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.UBRARY
MlChIg. .i State
University

 

 

 

This is to certify that the
thesis entitled

PERFORMANCE PROPERTIES OF A BIODEGRADABLE
FOAM (GFIREN CELL®) FOR PACKAGING APPLICATIONS

presented by

Samina Arif

has been accepted towards fulfillment
of the requirements for the

Master of degree in Packaging
Science

 

 

 

7 Major Profe'ssor’s Signature
& 7/2 5/0 7

Date

MSU is an affirmative-action, equal-opportunity employer

-.-.-.-.-.-u---------o-.—.---— -n-.-.--v--------.- -.-.-.-.-.-.-.-.-.-.- -------o-o---n--o-

PLACE IN RETURN BOX to remove this checkout from your record.
To AVOID FINES return on or before date due.
MAY BE RECALLED with earlier due date if requested.

 

DATE DUE

DATE DUE

DATE DUE

 

 

 

 

 

 

 

 

 

 

 

 

 

 

6/07 p:lCIRC/DateDue.indd-p.1

 

PERFORMANCE PROPERTIES OF A BIODEGRADABLE FOAM

(GREEN CELL®) FOR PACKAGING APPLICATIONS.

By

Samina Arif

A THESIS

Submitted to
Michigan State University
In partial fulfillment of the requirements
For the degree of

MASTER OF SCIENCE
The School of Packaging

2007

ABSTRACT

PERFORMANCE PROPERTIES OF A BIODEGRADABLE FOAM
(GREEN CELL®) FOR PACKAGING APPLICATIONS

By
Samina Arif

Green Cell® foam is a biodegradable foam packaging material produced from a
proprietary cornstarch blend. It is commercially available in a variety of laminations and
constructions. Cushioning ability and thermal resistance (R- value) are fundamental
properties needed to compete against synthetics. Since Green Cell® foam is starch based
and biodegradable, moisture is likely to affect its physical properties.

Cushioning characteristics and the R- values of 1 and 2-inch foams were determined as a
function of temperature and moisture content. ASTM method 1596 was used to
determine the cushioning properties and an ice melt method was used to determine
thermal resistance. Moisture sorption isotherms were developed at three temperatures
(20°C, 25°C and 30°C) to determine its moisture sensitivity. One-inch foam had a lower
G value at lower static stress than synthetic foams, but at higher static stress had higher G
values, while two-inch foam had G values similar to that of synthetic foam materials.
Dimensional changes were observed at higher relative humidity conditions especially at
30°C. The R-values at higher humidity were also less than that of synthetic materials.
Biodegradable Packaging materials will find niche markets, as long as their properties are
comparable to synthetic materials. Green Cell® foam’s hygroscopicity and its density
need to be more controllable, then this would open the door for new market opportunities
for this biodegradable foam manufactured from renewable resources. In the near, the

farm may make a significant in the area of biobased Packaging Materials.

Dedicated to my dear husband and son

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ACKNOWLEDGEMENTS

Words seem inadequate to express my feelings of gratitude, however, I would like to
thank Dr. Bruce Harte, Professor, The School of Packaging, MSU, East Lansing,
Michigan, for his continuous and substantive contributions during all phases of this
project. I, further, gratefully acknowledge all of his efforts and contributions to present
our research in two International proceedings (annual IFT conference2005, and 4th
International Biomechanics conference2003).

I extend my gratitude to Dr. Burgess for his insightful comments and very valuable
suggestions during our two poster presentations, master thesis writing and during all
phases of this Research.

Special appreciation to Dr. Ramani Narayan for serving on my guidance committee.
Thanks to all of my friends and teachers in the School of Packaging especially Dr. Rafael
Auras, providing the valuable information during my research when I was stuck.

I further would like to acknowledge to my Schoolfellow Krittika, Tanprasert (Kate)
giving her valuable time to help us to get our poster (Evaluation of biodegradable foam
for packaging applications) into the final shape when I was physically away from my
school.

Last but definitely not least; I would like to thank my family (husband and son) during
my very busy years of the school. My young son “Ibrahim Arif” could always cheer me

up even on the worst of the days and my husband who always kept me pushing forward.

iv

 

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TABLE OF CONTENTS

INTRODUCTION .................................................................................... 1
CHAPTER 1 ................................................................................... 4
1.0 Literature review .............. . ................................................................ 4
1 . 1 Introduction .................................................................................... 4
1.2 History ......................................................................................... 5
1.21 Early History ................................................................................. 5
1.22 1800’s .......................................................................................... 5
1.23 1900’s .......................................................................................... 6
1.24 1920’s .......................................................................................... 6
1.25 1960’s .......................................................................................... 7
1.26 2000 and Beyond ........................................................................... 7
1.30 History of Plastic Foam .................................................................... 8
1.31 .Early History (2680-2565 BC) ............................................................ 8
1.32 1000-1500 History ........................................................................... 9
1.33 1887 History ................................................................................ 10
1.40 Biodegradability ........................................................................... 1 1
1.41 Key Elements in Biodegradation ......................................................... 12
1.42 Bioplastics ................................................................................... 14
1.42.1 Starch ........................................................................................ 15
1 .43 Retrogradation .............................................................................. 16
1.43.1 Retrogradation process of starch ......................................................... 17
1.44 Thermal Insulation .......................................................................... 19
1.45 Green Cell® Foam ......................................................................... 22
1.45.1 Composition of Green Cell® foam ...................................................... 22
1.46 Foam Definition ............................................................................ 22
1.47 Types of Commercial Foam .............................................................. 23
1.47.1 Polystyrene foam .......................................................................... 25
1.47.2 Polyurethane Foam ........................................................................ 31
1.47.3 Polyolefin foam ............................................................................ 39
1.50 Manufacturing methods for Plastic Foams ............................................. 42
1.51 Injection molding .......................................................................... 42
1.52 Extrusion .................................................................................... 44
1.53 Other Processes ............................................................................ 47
CHAPTER 2 ......................................................................................... 50
2.0 Twin Screw Extrusion process ............................................................ 50
2.1 Cushioning Characteristics of Green Cell® Foam .................................... 53
2.1 1 Instrumentation ............................................................................. 53
2.12 Method ....................................................................................... 54

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2.13 Calculations .................................................................................. 55
2.14 Effect of % RH and temperature on G values ........................................... 56
2.15 Effect of Time on G values ................................................................ 57
2.2 Dimensional Changes ...................................................................... 58

Materials .................................................................................... 58

Methods ..................................................................................... 59

Dimensional changes at different relative humidity (%RH) conditions and

30°C ......................................................................................... 59

Material behavior at ambient conditions ................................................ 60

The Change in thickness of Green Cell Foam under Specific load ............... 60
2.3 Sorption isotherm .......................................................................... 61
2.31 To determine the moisture sorption isotherm of the product at 20°C, 25°C

30°C .......................................................................................... 61
2.32 Net weight changes ......................................................................... 63
2.40 The package insulating ability (R -Value) and bulk density of Green Cell®

foam ......................................................................................... 64
2.41 Materials .................................................................................... 64

Methods ..................................................................................... 65

Research Over view ....................................................................... 69
CHAPTER 3 ........................................................................................ 70

Results and Discussion .................................................................... 70
3.1 Cushioning characteristics of Green Cell Foam , G value at 25°C and 50%RH

and comparison of values ............................................................... 71
3.11 Time Effect on G values ............................................................... 78
3.12 Effect of relative humidity on G value ................................................. 79
3.20 Dimensional stability .................................................................... 87
3.21 Material behavior at ambient conditions ................................................ 93
3.22 Changes in thickness under load ......................................................... 95
3.23 Change in Thickness under load at ambient conditions .............................. 98
3.30 Moisture sorption ......................................................................... 100
3.4 Thermal insulation ....................................................................... 1 15
4.0 CHAPTER 4 .............................................................................. l 19
4.1 Conclusion ................................................................................ 1 19
4.2 Recommendations ........................................................................ 120

vi

APPENDIX -A .................................................................................... . 121

Cushioning Characteristics ....................................................... 121-139
APPENDIX- B ..................................................................................... 140
Dimensional Changes and Moisture gain/loss with respect to time at 11%

RH and 30°C ........................................................................ 140-174
APPENDIX- C .................................................................................... 175
Moisture Sensitivity of Green Cell® Foam ...................................... 175-196
APPENDD(- D ..................................................................................... 197
Thermal insulation properties calculations of Green Cell® foam ............ 197-199
APPENDIX- E .................................................................................... 200
Standards Salt Solution preparation ............................................. 200-202
References .................................................................................... 204-207

vii

LIST OF TABLES

Table 1. Table No.1. Major types of commercial plastic foam ..................... 23
Table 2. Typical Fragility Levels for Different Products ............................. 72
Table 3. Comparison of G value of Green Cell Foam® 2— inch thick
with the G values of other materials in the market.* (2” thickness,24 in
Drop height) ..................................................................... 74
Table 4. Comparison of G value of *Green Cell® foam with the G values

of other Commercial materials. (* 1” thickness 24” Drop Height). 77

Table 5. Comparison of G value of *GCF with respect to time Cell

(Thickness 1- inch Green foam) ............................................. 79
Table 6. G value and change in weight (Aw) of Green Cell® foam with

respect to time. .............................................................. 80
Table 7: Comparison of impact time and impact velocity before and after

keeping the material at specific %RH conditions .......................... 81
Table 8. Relationship between change in Thickness under load at

25°C and 50% RH .............................................................. 95
Table 9. Relationship between change in Thickness under load at 25°C

and 50% RH(* 2-inch Green Cell® foam) ................................. 96
Table 10. Relationship between change(A) .in Thickness at ambient conditions

(* 2-inch Green Cell® foam) .............................................. 98
Table 11. R-values of EPS cooler and Green Cell cooler at

different conditions .......................................................... 118

Tables Gl- G 7 Represent the information about the shock characteristics of Green

Cell® foam having thickness of 2- inch ............................. 121-124
Tables G 8 to Gl6.Represent the information about the shock characteristics of Green

Cell® foam having thickness of 2- inch ............................. 125-129
Table G17. Shock characteristic information before storing at different humidity

viii

conditions and 30°C ......................................................... 130

Table G18. Shock characteristic information after the storage study at different
humidity conditions at 30°C ............................................. 130

Table G19 (a, b and c). Comparison of shock characteristics of Green Cell® foam before
the storage studyand after the storage study at different relative

humidity (%RH) conditions and 30°C .................................... 131
Table G 20. Comparison of G values of Green Cell® foam at different relative
humidities with respect to time ............................................. 132

Table G 21-G23. Represent the information about the shock characteristics of Green
Cell® foam having thickness of 2- inch with respect to time . . ...133-134

Table G 24-G27. Represent the information about the shock characteristics of Green
Cell® foam having thickness of 1- inch with respect to time . . ...135-136

Table D l — D3. Dimensional Changes and Moisture gain/loss with respect to time at

11% RH and 30°C ...................................................... 140-141
Table D 4 mensional Changes and Moisture gain/loss with respect to time at
43% RH and 30°C ........................................................ 143-144
Table D 5-D8 Net Dimensional changes and weight loss/gain at 43% RH
and 30°C ............................................................... 145-146
Table D 9 — D13. Dimensional Changes and Moisture gain/loss with respect to time at
56% RH and 30°C ........................................................ 148-151
Table D 14 — D18. Dimensional Changes and Moisture gain/loss with respect to time at
75% RH and 30°C ........................................................ 153-156
Table D 19 — D23. Dimensional Changes and Moisture gain/loss with respect to time at
84% RH and 30°C ........................................................ 159-163
Table D 24 — D 28. Dimensional Changes and Moisture gain/loss with respect to time at
89% RH and 30°C ........................................................ 165-168
Table D 29 — D 33. Dimensional Changes and Moisture gain/loss with respect to time at
95% RH and 30°C ........................................................ 170-173
Table M . Initial moisture Content Calculations of Green Cell® foam ........... 175
Table M 1. ‘ Experimental Moisture Content “Me” Calculations at 20°C and different
humidity conditions ................................................... 176-181

ix

 

 

 

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Table M 2. RMS calculation for GAB model at 20°C and different %RH

conditions ....................................................................... 1 82
Table M 3. Experimental Moisture Content “Me” Calculations at 25°C and different

humidity conditions .................................................. 183-188
Table M 4. RMS calculation for GAB model at 25°C and different %RH

conditions ...................................................................... l 89
Table M 5. Experimental Moisture Content “Me” Calculations at 30°C and different

humidity conditions ..................................................... 190-195
Table M 6. RMS calculations at 30°C and different %RH conditions ............... 196
Table T 1. (R-Value ) calculation of GCF and EPS coolers at 50%RH and 25°C.

........................................................................... 197-198
Table T 2. (R-Value ) calculation of GCF and EPS coolers at 80%RH and 30°C

........................................................................... 198-199
Table T 3. Density calculation of l-inchand 2-inch Green Cell® foam ........ 199

Table S-l; Equilibrium Relative humidity values (standards and actual) for selected
saturated solutions ............................................................... 202

LIST OF FIGURES

Figure 1. Historic pyramids (2680-2565 BC) ............................................... 8
Figure 2. Easter island (1000-1500) ......................................................... .9
Figure 3. Statue of Liberty (1887) ........................................................... 10
Figure 4. Schematic diagram for biodegradation of polymers ............................ 11
Figure 5. Key elements for biodegradation process ....................................... 13
Figure 6 Shows the Plastic foam basic structure of Starch molecule .................... 15
Figure 7 —10 Examples of Green Cell® Foam practical usage ............................ 21
Figure 11. Major types of foam materials and their applications ........................... 24
Figure 12. Basic structure of polystyrene .................................................... 30
Figure 13. Basic diagram of Extruder machine ............................................... 47
Figure 14. Process Flow Diagram of Green Cell® Foam .................................... 52
Figure 15. Overall Research overview of the Performance properties of

Green Cell Foam ..................................................................... 69
Figure 16. Material damage at 1.75psi ,determine G value ,1“ impact .................... 74
Figure 17. G values of Green Cell® foam Vs Static Stress (psi) * 2-inch thick

GCF .................................................................................... 75
Figure 18. Comparison of the G value of the GCF with the G values of other materials

in the market available material. * (2” thickness 24” Drop Height) ......... 76
Fig19. Graphical representation of the G value of ‘Green Cell® foam with the G

values of other commercial materials. *(l” thickness 24” Drop Height). . ...77

Figure 20. Graph between G values of GCF Vs Static stress (* l-inch thick GCF). 78
Figure 21. (Front view) Comparison of Green Cell® foam kept at 25°C, 50%RH and

30°C, 75% RH ........................................................................ 81
Figure 22 (Side view) Comparison of Green Cell® foam kept at 25°C, 50%RH and

xi

30°C, 75% RH ........................................................................ 82

Figure 23. (Side view) Comparison of Green Cell® foam kept at 25°C, 50%RH and
30°C, 84% RH ...................................................................... .82
Figure 24. Material kept at 84% RH and 30°C ............................................... 83
Figure 25. (Front View) Comparison of Green Cell® foam kept at 25°C, 50%RH and
30°C, 89% RH ...................................................................... 83
Figure 26. Material kept at 89% RH and 30°C(Fungus Report) .......................... 84
Figure 27. (Side view) Comparison of Green Cell® foam kept at 25°C, 50%RH and
30°C, 89% RH ...................................................................... 84
Figure 28. (Front view) Comparison of Green Cell® foam kept at 25°C, 50%RH and
30°C, 96% RH ..................................................................... 85
Figure 29. Material kept at 96% RH and 30°C(Fungus Report) ........................ .85
Figure 30 (Side view) Comparison of Green Cell® foam kept at 25°C, 50%RH and
30°C, 96% RH ................................................................... 86
Figure 31. Comparison of samples maintained. at 84% RHI30°C and 50%RH /25°C.
(Front view) ........................................................................ 88
Figure 32. Comparison of samples maintained at 84% RH/ 30°C and 50%RH /25°C
(Side view) ........................................................................ 88
Figure 33. Comparison of samples maintained at 75% RH/ 30°C and 50%RH/25°C.
(Side View) ........................................................................ 89
Figure 34. Comparison of samples maintained at 75% RH/ 30°C and 50%RH /25°C.
(Front View) ........................................................................ 89
Figure 35. Net Change in thickness at 30°C at different humidity conditions ........... 90
Figure 36. Change in Width at 30°C at different humidity conditions ................... 91
Figure 37. Change of length at 30°C and different humidity conditions ................. 92
Figure No.38 (a and b). Comparison of samples kept at 95% RH, 30°C and 50%RH and
25°C. (Front View) ................................................................. 93
Figure 39. Comparison of 2-inch fresh and three month old material (side view) ...... 94
Figure 40. Comparison of l-inch fresh and three month old material ..................... 94

xii

Figure 41.

Figure 42.

Figure 43.

Figure 44.

Figure 45.
Figure 46.
Figure 47.
Figure 48.
Figure 49.
Figure 50.
Figure 51.

Figure 52.

Figure 53.
Figure 54.
Figure 55.

Figure 56.

Figure 57.
Figure 58.
Figure 59.

Figure 60.

Graph between Time (days) Vs Thickness of Green Cell® foam
at 25°C and 50%RH at constant load(* l-inch Green Cell® foam .......... 96

Graph between Time (days) Vs Thickness of Green Cell® foam
at 25°C and 50%RH at constant load(* 2-inch Green Cell® foam) ......... 97

Change in thickness under load at 25°C and 50%RH for 1 inch and 2-inch
GCF .................................................................................... 97

Relationship between change Thickness under constant load at 25°C and
50% RH(* 2-inch Green Cell® foam) ........................................... 99

Plot between the moisture content (%) and relative humidity RH (%). ....102
Plot between the moisture content (%) and relative humidity RH (%). ....103

Plot between the moisture content (%) and relative humidity RH (%). 104

Sorption isotherm of GCF at 20°C .............................................. 104
Sorption isotherm of GCF at 30°C .............................................. 104
Sorption isotherm of GCF at 25°C .............................................. 105
Plot of aw/Me and water activity at 20°C ....................................... 106
Comparison of Moisture sorption isotherm for Green Cell Foam based on

experimental data and GAB model at 20°C .................................... 107
Graph between aw/Me and water activity at 20°C ............................ 108
Moisture sorption isotherm of Green Cell® foam at 25°C .................... 108

Graph between moisture equilibrium content vs. Water activity

30°C and different relative humidity conditions ............................ 109
Comparison of the moisture sorption isotherm (GAB and experimental) of

Green Cell® Foam at 30°C ...................................................... 110
Fungus report at 20°C and 96% RH ............................................ 111

Comparison of fresh sample and material kept at RH75% and 30°C. . .. 112

Comparison of fresh sample and material kept at RH 95% and 30°C. .. 112

Net Change in weight at 30°C and different humidity conditions ........... 114

xiii

Figure G1. Graph between G value and Time (days) ....................................... 132

Figure G 2. Graph between G values and Relative Humidity conditions (RH%) ....... 133
Figure G 3. Comparison of Green Cell® foam material kept at 50% RH, 25°C and
11% RH, 30°C. (Front view) .................................................... 137

Figure G 4. Comparison of Green Cell foam material kept at 50% RH, 25°C and

11% RH, 30°C. (Side view) ........................................................ 137
Figure G 5. Comparison of Green Cell® foam material kept at 50% RH , 25°C

and 43% RH, 30°C.(Front view) ............................................... . 138
Figure G6. Comparison of Green Cell foam material kept at 50% RH, 25°C

and 43% RH ,30°C.(Side view) .................................................. 138
Figure G 7. Comparison of Green Cell foam material kept at 50% RH, 25C

and 43% RH ,30C.(Front view) ................................................ 139
Figure G 8. Comparison of Green Cell foam material kept at 50% RH, 25°C

and 43% RH, 30°C.(Side view) ................................................ 139
Figure Dl-a. Dimensional changes at 11% RH and 30°C .................................... 141
Figure Dl-b.Weight changes at 11% RH and 30°C ........................................... 142
Figure D 2. Dimensional changes at 43% RH and 30°C ..................................... 147
Figure D 3. Moisture gain/loss at 43% RH and 30°C ........................................ 147
Figure D 4. Dimensional changes at 56% RH and 30°C .................................. 152
Figure D5. Moisture gain/loss at 56% RH and 30°C ......................................... 152
Figure D6. Dimensional changes at 75% RH and 30°C ..................................... 157
Figure D 7. Moisture gain/loss at 75% RH and 30°C ......................................... 158
Figure D 8. Dimensional changes at 84% RH and 30°C ..................................... 164
Figure D9. Moisture gain/loss 84% RH and 30°C ........................................... 164
Figure D10.Dimensional changes at 89% RH and 30°C .................................... 169

xiv

Figure D 11.Moisture gain/loss at 89% RH and 30°C ........................................ 169
Figure D 12.Dimensional changes at 95% RH and 30°C .................................... 174

Figure D13. Moisture loss/gain at 95% RH and 30°C ........................................ 174

XV

 

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Nomenclature

D: density

M = mass of the specimen

L1 = length of the specimen

L2 = width of the specimen

T = original thickness of the specimen in
H = free fall drop height

Vi = measured impact velocity

G = acceleration due to gravity 386
Dynamic set can be calculated

T = original thickness of the specimen

F = thickness of specimen after test

W, = Initial weigh of the product

Wd = Final weigh of the product

We: Equilibrium or final weight of the product
Wiz Initial weight of the product

Mi: Initial moisture content of the product
Me: Equilibrium moisture content
lb:pounds

in: Inches

in/sec: inches per second

sec: second -

xvi

in Hg : inches of mercury

psi : pounds per inches

g: grams

inches/sec2: acceleration

lb/ft3: pounds per feet cube.

pcf : pounds per feet cube

BTU/lb: British thermal unit per pound
Temp. : Temperature

%RH : Percentage relative Humidity
GCF : Green Cell® Foam

Aw : Net weight

AV : Change in velocity

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INTRODUCTION

Through plastic engineering, it was recognized that expanded structures foams could be
easily achieved with polymers, especially in thermally reversible plastics. During the
twentieth century, polymer synthesis was greatly enhanced to improve polymer
structures. Several methods were developed to create a broad range of polymer structures
during the middle and later part of this century. This was the era when industrial foams
were developed. Also during this time, companies and municipalities faced major
problems in disposing of plastic foams because they are lightweight and bulky and do
not lend themselves to a viable economic and environmentally responsible recycling
operation because they are expensive to handle and transport. Synthetic foams are not
biodegradable, which makes disposal in soil or composting operations untenable.

Further, issues such as sustainability, industrial ecology, biodegradability, and
recyclability are becoming major considerations in a company’s product packaging

design, especially with single use disposable packaging.

There is thus, a market need for bio-based, biodegradable foam plastic packaging that can

be safely and effectively disposed of in soil or in composting operations, and that has all

. . ® .
of the current foam plastics performance requrrements. Green Cell foam rs a

commercially available, biodegradable foam produced from a proprietary cornstarch. It

has recently become available in a variety of laminations and constructions. To compete

with other presently available synthetic plastic foams, Green Cell® must have similar

performance characteristics. Cushioning and thermal resistance (R-value) are

 

 

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fundamental properties required for the foam to function act as a Packaging material for
insulating and cushioning applications. Since Green Cell® is biodegradable, it will absorb

some moisture, which will likely affect the above preperties.
ASTM standard 1596 was used to determine cushioning characteristics at 25°C and

50%RH and these results were compared with the published data of other synthetic

plastic foams available in the market. l-inch and. 2-inch thick Green Cell® foams were

evaluated. Green Cell® foam having a 2-inch thickness had G values similar to other

®
synthetic plastic foams. However, l-inch thick Green Cell foam had lower G values at

lower static stress, but at higher static stress showed significantly higher G values as

. . ®
compared to the synthetic plastic foams. Green Cell foam was also stored at seven

different relative humidity conditions at 30°C for two months and then tested to
determine its G values. Another experiment was conducted to determine the time effect

on G values and it was observed that G values decreased with passage of time.
The density of 2-inch thick Green Cell® foam was determined to be 3.37lbs/ft3, while 1-

inch thick foam had a density of 3.03Ibs/ft3.

Change of thickness under load at standards conditions and at ambient conditions was
also observed. No significant change in thickness was observed. Material behavior at
ambient conditions was also observed. One inch and two inch thick material was kept
under observation at ambient conditions for about three months where relative humidity
and temperature varied between 50%-85% and 70°F-80°F. Significant increase in

thickness was observed, demonstrating that the material is hygroscopic.

 

 

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Dimensional changes were observed at different humidity conditions and at 30 °C (86°F)
after three weeks. The most expansion in dimensional characteristics occurred at 75%
and 84% relative humidity and the material gained moisture at these conditions. The
material also gained moisture, but shrunk at higher humidity conditions (88% and 95%).
No significant dimensional change was observed at 11%, 43% and 54% RH.

Moisture sorption isotherms at three temperatures (20°C, 25°Cand 30°C) were developed

to determine its morsture sensrtrvrty. Initial morsture content of Green Cell Foam was

found to be =0.1263 gHZO/g solid. GAB model was used to develop the sorption
isotherms. GAB model results were compared with experimental values.

The ice melt method was used to measure the package insulating ability and the thermal

resistance (R- value). R-values of EPS and Green Cell® coolers were determined at

standard conditions (50%RH, 72°F) and at 86°C, 80%RH. EPS has a 10% higher R-value

than Green Cell® foam at standard conditions. But R-value of EPS cooler was found to

be 20% higher at 86°F and 80%RH reflecting that Green Cell® foam degrades with

increase rn temperature and relative humidity. Green Cell prcks up morsture, WhICh

increased its thermal conductivity and lowered its R- Value.

Biodegradable packaging materials will find niche markets, as long as their properties are

comparable. To be used more broadly, Green Cell® foam, must be modified to both

control its hygroscopic properties and weight problems (Green Cell® foam has high

density). In the near future, the farm may make a significant contribution for non-

traditional based uses of starch.

 

 

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CHAPTER 1

LITERATURE REVIEW

1.1 Introduction

The discovery of Bioplastic is presented in the feature article “How green are green
Plastics” by Tillman U. Gemgross, and Steven C.Slater. The author starts the paragraph
in the following way,

“Driving down a dusty gravel road in central Iowa, a farmer gazes toward the horizon at
rows of tall, leafy corn plants shuddering in the breeze as far as the eye can see. The
farmer smiles to himself, because he knows something about his crop that few people
realize. Not only are kernels of corn growing in the ears, but also granules of plastic are
sprouting in stalks and leaves”[46].

Growing plastics, which seems achievable in the foreseeable future, looks more
appealing than manufacturing plastic in petrochemical factories. According to the article
‘how green are green plastics’, “the plastic manufactured in the petrochemical factories
consume about 270 million tons of oil and gas every year worldwide. Fossil fuel is the
basic source, which provides both the power and the raw materials that transform crude
oil into common plastic. It is difficult to imagine everyday life without plastic. But the
sustainability of that production has increasingly been called into question. Known global
reserves of oil are expected to run low in approximately 80 years, natural gas in 70 years
and coal in 700 years but the economic impact of their depletion could bit much sooner.
As the resources diminish, prices will go up—a reality that has not escaped the attention

of policymakers”[46].

Biochemical engineers are pleased by the discovery of bioplastics/biodegradable plastics.
Plant based plastic can be “Green” in two ways, plastic can be made from a renewable
resource and it can break down upon disposal [16].

Using natural biopolymers is not totally a new idea. In one form or another, green plastics
have been around for a long time. A brief review of green plastics (biodegradable

plastics) is followed by a review of plastic foams.

1.2 History

1.21. Early History

Some natural resin was used even during the early Roman and Middle Eastern times.
Like amber and shellac, gutta (one of the series of small drop like ornaments on a Doric
entablature.), percha‘s name has been mentioned throughout history.

Native Americans used to make ladles and spoons from animal horns long before there
was any European contact. In Europe, molded horn jewelry and snuflboxes were very

popular in the eighteenth century [16].

1.22. 1800’s

Meaningful commercialization of bioplastics actually began during the middle of the
nineteenth century. An American inventor, John Wesley Hyatt Jr. was looking for a
substitute for ivory in the manufacture of billiard balls. He was able to patent a cellulose
derivative for coating non-ivory billiard balls in 1869. His effort was, however, affected
by the coating's flammability. Balls were occasionally ignited when lit cigars accidentally

came into contact with them. Hyatt did not loose his focus and continued working on this

 

pm:

“it:

1.23

 

 

 

 

 

35 .

4‘? 1.
er‘

\V.‘

CO:

CT‘

 

project and soon developed celluloid, the first widely used plastic. Today it is most

widely known for its use in photograph and movie films [16].

1.23 1900’s

In the 19005 the history of plastics changed dramatically, as petroleum started to emerge
as a source of firel and of chemicals. Early bioplastics were replaced by plastics made
from synthetic polymers. The production of plastics occurred on a very large scale after

World War II, and continues to the present time [16].

1.24 1920’s

In the 19205 Henry Ford experimented using soybeans in the manufacture of
automobiles. He had a desire to find non-food applications for agricultural surpluses,
which existed as they do now. Soy plastics were used in number of automobile parts, like
steering wheels, interior trim, and dashboard panels. Ford was able to produce a
complete prototype "plastic car." He exhibited the prototype with great fanfare in 1941
but was not able to commercialize a new plastic car by the end of that year, because of a
variety of reasons. At this point, World War II played a role; armament work supplanted
almost everything else, and steel shortages limited all non-defense production. Today,
plastic automobile parts are common, but the use of plastics made from renewable raw

materials got side-tracked [16].

1.25 1960’s
Cellophane is a well-established bioplastic. This material is derived from cellulose. Its
peak production was recorded during the 1960’s but it is still being used in packaging for

candy, cigarettes, and other articles though its total usage in Packaging has substantially

decreased [16].

1.26 The 2000’s and Beyond

Demand for plastics material is continually growing and it is not abating. The plastics
industry is an important component of any country’s economy in today’s world. The US.
plastics industry has over 20,000 facilities that produce or distribute materials or
products. The industry also employs over 1.5 million workers, and ship over $300 billion
in products each year [16].

The plastics industry does have some concerns, however pressures relating to waste and
diminishing resources are major hurdles that are leading many to re-discover natural
polymers and use them as materials for manufacturing and industry. Because of this,
there is an increasing interest in a new generation of green /biodegradable plastics [16].
Research on starch-based products has taken place in many countries around the world.
The Australian Government funded in 1995 a research project to develop starch-based
plastics from corn and wheat, using water and glycerin as a plasticizer. The
biodegradable plastic society was formed in 1989 with 48 member companies located
mainly in Japan. By 1990, the membership increased to 69 companies, including a
significant number of non-Japanese members. In 1992 a US Bio/environmental society

was formed and had over 200 members by 1998. As an example, many companies sell

 

 

 

Oi

fl
I
'.1

 

starch based foam peanuts for loose fill packaging as a substitute for expanded

polystyrene [21].

1.3 History of Plastic Foam

The texture of matter has been modified since ancient times. Survival of the human race
depended on softening rice and other foods using yeast, water and heat to make these
ingredients soft enough so that they would be acceptable to digestive organs. These
techniques were designed to create expanded structures. These structure can be found
everywhere in nature, ranging from tree pulp to marine organisms [46].

Through plastics engineering, it was recognized that expanded structures could be easily
achieved in polymers, especially in thermally reversible plastics. During the twentieth
century, polymer synthesis was upgraded to enhance the polymer structure. Several
methods were developed to create a broad range of polymeric products, during the middle

of this century. This is the era when industrial foams were developed. [46]

1.31 Early History (2680-2565 B.C)
It may have stated before 2680 BC, no one knows for sure, but the architects of

Stonehenge engaged the services and discoveries of foam masons. [7]

 

Figure 1. Historic pyramids (2680-2565 B.C)

Phg.

his

{55’

311'.

 

Pharoah Rameses II (2680-2565 B.C) presented the idea of a gigantic stone pyramid to
his engineers. They were, at that time hardly enthusiastic. No one wanted to spend the
rest of his career—watching slaves, stacking stones on top of each other. Yunghotstuff II ,
an intelligent bright engineer presented the idea of using foam for the pyramids. He
explained that the lightweight blocks would skim easily over the sand, and would be
easily elevated, as it grew taller. This also resulted in the tremendous reduction in
building cost. After that, pyramids popped up all over Egypt and they remain there
resisting the elements of sun and sand, a memorial to human ingenuity and the power of

foam [7].

1.32 1000-1500 History

Recent ethnographic studies of today’s Easter Islanders have revealed a fondness for
decorating the front’s parts of their homes with small icons. Experts have concluded that
they were simply large-scale foam lawn ornaments. The ancient figures on Easter Island

are a confirmation of the durability of well-build foam art [7].

Ea t r
tiara...

 
 

Figure 2. Easter island (1000-1500)

1.33 1887 History
When French Sculptor Fredeic Auguste Bartholdi was commissioned to build a
monumental statue, arcane zoning regulations could have blocked the famous statue

installation.

Stat e of
rty

 

Figure 3. Statue of Liberty (1887)

Before the American Revolution, New York City ordinance 56-0894 required that all
structures and vessels in New York Harbor be able to float. Originally the Statue of
Liberty had been originally commissioned to be built of bronze, sculptor Bartholdi
realized that his project could be easily scuttled if he could not propose an alternative
construction material. Bartholdi’s own countryman Gustave Eiffel was studying the use
of foam as substitute for steel in large engineering constructions. Eiffel was persuaded to
share his patented procedure with the sculptor. The bottom line is that, “it was foam,
francs and delightful Bordeaux that saved the jour” [7].

Polymer synthesis and processing have been improved since the middle of the twentieth
century. Many foaming methods have been started and transferred from lab scale to

industrial scale [22].

1.4 Biodegradability:

“The term biodegradability means that living organisms can use the plastic as a food
source, transforming its chemical structure within a reasonable period of time” [5]. In
practice we rely on microorganisms to transform carbon in the polymer to C02, CH4 and
other small molecules. Usually the time period required is several weeks to months. One
way to obtain biodegradable plastic is to use natural polymers, that is, those formed by
living organisms [14].

In figure 4, the basic “Central Principle” for biodegradation of polymers is shown in the

form of a schematic diagram.

 

 

 

Polymer
l (1
Conjugation, oxidation or hydrolysis Outside Cell
Polymerization l (Exo or Endo enzymes)
Depolymerization 1
Mineralization

I. inside the Cell

/\
H20 C02 _.

v
Biomass

 

 

Figure 4. Schematic diagram for biodegradation of polymers

ll

This process consists of two key steps: first, depolymerization or chain cleavage and
second, mineralization. [14]

The first step normally occurs outside of the organism (usually bacteria or fungi due to
the size of the polymer chain and insoluble nature of many of the polymers). In this step,
extra cellular enzymes are responsible for acting either endo (random cleavage of the
internal linkage of the polymer main chains) or exo (sequential cleavage of the terminal
monomer units in the main chain). [14]

Sufficiently small oligomeric chains are formed and then transported into the cell where
they are mineralized. The cell usually derives metabolic energy from the mineralization
process and the products, apart from ATP, are gases (e.g. C02, CH4, N2), water salts,
minerals and biomass [14].

Traditional plastics cannot undergo biodegradation; the reason is because of their long
polymer chains. These long chain polymers are too large and too tightly bonded such that
they are very difficult to break apart, and thus can not be transformed into relatively
simple components [16].

However, plastics based on natural plant polymers, such as wheat or cornstarch have

molecules that are readily attacked and broken down by microbes [16].

1.41 Key Elements in Biodegradation

There are three key elements in the biodegradation process as shown in the following

diagram. If any of the elements (below) is lacking, then the entire process will stop.

12

Biodegradation

Substrate
Organisms 1) Chemical bond Environment
1) Appropriate enzymes 2) Branching 1) Temperature
2) Appropriate enzymes 3) Hydrophilicity/ 2) Oxygen
Level Hydrophobicity 3) Moisture
3) Co- metabolism 4) Stereochemistry 4) Salts
4) Aerobic,anaerobic,facultative 5) Molecular weight 5) Metals
5) Enzymes kinetics 6) Chain flexibility 6) Trace nutrients
6) Inhibitors/inducers 7) Crytalinity 7) PH
7) Enzyme location 8) Interation with co 8) Redox potential
(intra,extra-cellular) polymer coatings 9) Stability
8) Predators 9) Surface area 10) Pressur
11) Alternate carbon
12) Light
Figure 5. Key elements in the biodegradation process [14]

13

 

 

 

 

1.42 Bioplastics:
Bioplastics are materials with plastic-like properties made from renewable resources such

as corn, wheat, rice, soy and potato:

Biopolymer(s) + Plasticizer(s) + other additive(s) = Bioplastic.

Biopolymers are inherently biodegradable. Biopolymers almost always have oxygen or
nitrogen atoms in their polymer backbones. This particular feature is mainly responsible
for their biodegradability [16].

There are three main new and important types of bio plastics material (carbohydrates,
Lignins and Polyesters). They differ according to the means of commercially producing
the resins from which the bioplastics are produced. There are also ready-made polymers
existing in nature, which can be used in manufacturing bioplastics. Starch being the
prime example [16].

Figure 6 shows the basic structure of a Starch Molecule. [49]

14

1.42.1 Starch

Structure of Stargh Polymers

CHZOH CHZOH
H H
OH H OH H

_—o __
H H H H

 

Linesr a —l-4- glucan—amylose
200 to 2000 anhydroglucose units
6)

H H HZOH
HO
EH2 CHZOH

 

 

 

 

 

Branched polymer —amylopectin
a -1,4-glucan with 1,6-glycosidic linked braches containing 20-30 anhydroglucose units

 

Figure no. 6 The basic structure of a Starch Molecule

Starch is the main component of most human and animal diets. It is found in the storage
organs of plants in the form of partially crystalline water-insoluble granules. [49] Starch
is composed of anhydroglucose units, which are the major source of storage energy in
various plants in nature. It can be widely found in cereal grain seeds (e.g. corn, wheat,
rice, sorghum), tubers (e.g. potatoes), roots (cassava, sweet potatoes, arrowroot), legume
seeds (e.g. peas beans and lentils), fruits and leaves (tobacco). [47]

The starch molecule consists of two master polymer components, amylose and
amylopectin. Their structure and the relative amount of both populations play an

important role in the starch properties. The amylose content and degree of polymerization

15

 

(DP) are important in the physical, chemical and technological properties of starch. [46].
Cornstarch typically consists of 28% amylase and 72 % amyl pectin but it can be
genetically modified to have as much as 85%. [22]

Starch based material is important not only because it is the least expensive material but
also it can be made into a thermoplastic when properly plasticised with water or other
plasticizers. Therefore, starch formulations can be made into film or container by any
method used for synthetic resins like extrusion, injection molding and thermo- forming
[16]. The main limitations of starch-based formulations are physical/chemical properties
such as poor water resistance and modest strength [16].

Starch based materials are being used for a number of applications and several major
companies produce starch based resins. These resins further have been used to
manufacture agriculture covers, compost bags and trash bin liners, house hold items such
as disposable bowls, eating utensils and straws, single use disposable packaging film,
diaper backing, disposable golf tees and personal hygiene articles like combs and

disposable razors. [16]

1.43 Retrogradation

The aging of starch systems has a major effect on the quality of many products. Starch-
based foods, such as bread and dough, stale with the passage of time. Low fat baked, or
convenience foods are particularly susceptible. Furthermore in non-food uses of starches,
for example in paper and adhesives applications, retrogradation affects the processing and
final properties of the product. Similarly, one of the most important practical problems

with recently developed starch plastics is their tendency to become brittle over time, a

16

process analogous to the staling process in baked goods. [47] The basic definition of
retrogradation is the returning to a former state or passing from a more complex to a

simpler biological form. [30]
1.43.1 Retrogradation process of Starch

When Starch is heated with water, it gelatinizes and the amylopectin is swelled. Starch
particles then proceed to harden. This process is called retrogradation. [39]

F. Lionetto et all, in his paper [24] described the process of retrogradation. Starch
consists of mainly two polysaccharides, amylose (linear polymer) and amylopectin
(highly branched macromolecule). Amylopectin is believed to be the main contributor to
the crystallinity of the starch granule [24].

The starch granules are made of concentric amorphous and semi-crystalline growth rings.
Starch granules are insoluble in cold water, but, when heated in the presence of excess
water, they swell. This swelling is reversible up to a certain temperature. This particular
temperature is known as the gelatinsation temperature, where a more pronounced
swelling takes place, accompanying the melting of the crystalline regions. Principally
linear amylose becomes soluble and leaches out of the disrupted granule. In addition to
thermal processing, the conversion of starch from its native partially crystalline granular
structure to a polymeric solution/melt and subsequent molecular degradation can be
driven by mechanical shear (e. g. in extrusion), chemical (e. g. through the use of solvents)
and biochemical (e.g. through enzymatic hydrolysis) processes, etc [24].

Upon cooling, and the during early storage stage, amylose gelation or retrogradation

occurs while in longer term storage (hours-weeks depending on composition and storage

17

conditions), amylopectin retrogradation occurs, which leads to the partial recrystallisation
of amylopectin producing an increase of firmness and a decrease of water-holding
capacity [24].

Retrogradation occurs because gelatinized starch is often super cooled and stored below
its melting temperature and therefore is not in thermodynamic equilibrium. Molecular
packing and crystallization occurs during storage. Starch retrogradation is scientifically
and technologically important since it leads to significant changes in the mechanical
properties of starch-based products and thus greatly affects their sensory (e.g. texture and
flavor perception), nutritional (availability) and processing (shredding, cutting, etc.)
characteristics. [24]

This is further described by Zhenghoug Chen [50] in his dissertation; starch pastes may
become cloudy and eventually deposit an insoluble white precipitate during storage. This
phenomenon is caused by recystallization of starch molecules. Amylose is considered
primarily responsible for the short —term retrogradation process due to the fact that the
dissolved amylose molecules reorient in parallel alignment. But the long-term
retrogadation is represented by slow recrystallization of the outer branches of
amylopectin [50]. Basically the rate and the extent of retrogradation increase with an
increasing amount of amylose. Retrogradation also depends on starch concentration,
storage temperature, PH, process temperature, and the composition of the starch paste.
Retrogradation is generally stimulated by high starch concentration, low storage

temperature and PH values between 5-7. [50]

18

1.44 Thermal Insulation

Defining R-Value

The demand for quality building insulation has soared during the 1970’s. At that time
many new products were introduced with many conflicting claims pertaining to their
insulating abilities. The federal Trade Commission with the participation and support of
the insulation industry created an objective method to report the performance of
residential insulating materials. This method was called the R-value Rule. [23]

Plastic foams are becoming more and more important in insulation. Price, performance
and special design considerations are the most significant features, to consider in
selecting any foam to be used for insulation. [12]

To reduce winter heat loss and summer heat gain, plastic foam is being more prominent
than other materials because of their significant energy saving capability. Plastic foam
insulation is the only viable method for building foundation walls and flat, steel deck
roofs, and for packaging needs [23]

Other insulating materials like mineral wood and fiberglass are being used in the building
industry as alternatives to foam board stock. Vacuum panels are also being used for
building insulation applications. Insulation for flat roofs and below grade foundation
walls requires compressive strength and the moisture resistance of closed cell foam. This
cannot be found with other insulating materials. [12]

The R- value gives information regarding product labeling (R-value) and advertising, and
mandates specific ASTM methods for thermal testing. The basic purpose of the R-value

Rule is to create a level —playing field for competing insulating materials.

19

“The R-value Rule has been helpful in comparing different brands of the same type of
insulating materials,” said Betsy de Campos, executive director of EPSMA, “ but as more
sophisticated materials and higher technology construction systems are introduced into
the building industry we find that the R- value of the material does not tell the whole
story.”[23]

R- value is based on the mathematical term known as R- factor. The term R- value was
developed to represent the ability of an insulation material to restrict flow. Thermal
resistance® of a material is its resistance to heat flow and is expressed as the reciprocal of
the material thermal conductivity. Simply put, the greater the R-Value the better the

insulation. [23]

1.45 Green Cell® Foam
Extruded starch foam is used as a loose fill packaging material (pallets or peanuts). Green
Cell® foam is a commercially available, biodegradable foam material produced from a

proprietary cornstarch. It has recently become available in a variety of laminations and

constructions. Green Cell foam can be used as a cushioning material and in applications

where thermal insulation is essential [5].

KTM Industries, Inc. develops, manufactures and markets new bioplastic technologies
for applications that incorporate proprietary, non-toxic, environmentally safe bio plastics
like Green Cell® Foam. Large-scale production of these polymers is being developed

because they have been found to have important commercial uses [5]. Typical current

applications for the use of Green Cell® Foam can be seen in Figures 7 to 10.

20

"1. :

 

 

 

(1":1'

Fig

 

 

"

.11.!
. ‘5
_Is

.. -.-
‘I- & fly» ..
r
.-

m '9'! I .

 

 

Figure 7. Die Cut

Figures 7 and 8.

 

 

 

 

Figure 9. Medical Shipper

Figure 10. Shipping Coolers

 

 

Figure 8. Die Cut Laminated End Cap

Green Cell® Foam is presently used as a Die Cut and

as a Die Cut Laminated End Cap

 

Figure 9 and 10. The major uses of Green Cell® Foam are for Medical Shipper

and for shipping Coolers purposes. [5]

21

 

I’)

""3

1.45.1 Composition of Green Cell® Foam.

1) Green Cell foam is made from Starch, HYLON VII (High Amylose, 70% Amylose)
with an inherent moisture content of 1’ 1.2%.

2) Water used as the plasticizing agent, as well as the Blowing agent (IO-12% of the dry
feed) for all products.

3) BLOX (Dupont), to provide adhesion and durability resin with the flexibility and
process ability of thermoplastic resins.

Green Cell® foam is made in thick nesses (t) of 1 and 2-inches. [5]

1.46 Foam Definition

According to S.T.Lee author of the foam extrusion book, “Foam can be defined as a
gaseous void surrounded by a much denser continuum matrix, which is usually in a liquid
or solid phase”. This phenomenon widely exists in nature, in cellulose wood, and marine
organisms. Foams can also be made using different synthesis processes (foamed plastics).
[45]

Plastics foams can be classified in different ways, for instance, as flexible and rigid, as
sheet or board, as low-density or high-density, as closed cell and open cell, and by cell
size as foam and micro cellular. To minimize confusion, it is desirable to have a standard
nomenclature for foam such as the one from IUPAC. In 1996, over six billion pounds
(three metric tons) of synthetic foamed plastics were consumed in the United States.

Today’s, this material is widely used for a variety of packaging applications. [45]

22

IiIA

1.47 Types of commercial foams
Types of commercial foams are shown in the table No.1 and Major types of foam and

their applications can also be seen in figure 11,.

Table No.1. Major types of commercial plastic foam

 

 

 

 

 

 

 

 

 

Types of Foam Types of Foams

Poly styrene foam Pyranyl foam

Poly Urethane foam Miscellaneous cellular plastics foams

Poly olefin foam Synthetic rubber and silicon foam
Polyvinyl-chloride foam Inorganic foams

Phenolic foam Expanded beads and spheres
Urea-formaldehyde foam Acrylonitrile and acrylate copolymer foams
Epoxy foam

 

 

23

 

Poly etymno

PIR

I]

 

 

'- 60-an

*— Rigid Pom-1e

lneulation —"

 

— Phenolc < 5% ——I:
b Appll-noo -— Rigid Pom -I:

Id PD —
.. m... ___r: :~,.,,,,,,M,,“__

Polyetymne- —'E
M %
Polyolefln ———-C
Packaging m neulatlon __ Polyurelhene

Moulded —-—- Polyolofln
Board about ---—- Polyolefln

 

__.__._._ Flexible
Cushioning ‘
"9““ Polyurethane

Moulded '———— Polyolefln m

Integral Sldn Polyurethane -—-——

83W Sheet Poly-olefin ——
Polyolefin ——

E a.“ —-——E _

Polystyrene

 

 

Figure 11. Major types of foam materials and their applications

Boerdmck

PIpO

Boom flock/F ioxblo Faced
Laminated Roofing

Sandwich Panel. 0
SproyIPour-in-Plaoo Rooting
Slabaaook

Plpe-In-Plpo

Boerdelock

Pipe HVAC

Roll-lg embrafireezete
Picnic BoxedOther
Sandwich Penele

Sandwich Panels

Single Service Ueee
Food Packaging
Mlec. Packaging
Frmiture

Cushion Pad-raging

Cushion Packaging
Cuehlon Packaging

Automotive Interior:
Corp“ Underley
Funlture

Sodding

Funltun

Automotive Cushioning
Auto Banner Systema

Auto Bumper SW
Steering WM.
Flotation - Life Vests
Flotation

Flotation

A more description of these foams and these uses in packaging follows.

24

1.47.1 Polystyrene foam

Modern man has known about styrene for centuries. Styrene is present as a naturally
occurring substance in many foods and beverages including wheat, beef, strawberries,
peanuts and coffee beans. It is also found in the spice cinnamon. Its chemical structure is
similar to cinnamic aldehyde (the chemical component that elicits cinnamon's flavor).
Polystyrene foam is one of the rigid foams currently sold, and in fact dominates the
market with urethane foam second. [13] Polystyrene foam was made first in Great Britain
in 1943 but the early development was accomplished in Sweden during the mid 1930’s.
DOW Chemicals Company was first introduced as extruded polystyrene foam in the
United States in 1943.The foam was used during world war II for construction of life

rafts on troops transports and for floating equipment to shore. [l 3]

Styrene is a primary raw material and is a petroleum by-product. Styrene played a vital
role during World War II. It was also used in the production of synthetic rubber during
that time. After the war, the styrene utilization shifted towards the manufacturing of
commercial polystyrene products. Synthetic styrene is also used in the manufacture of
products such as automobile parts, electronic components, boats, recreational vehicles,
and synthetic rubbers. [37]

Polystyrene (PS) meets tight (stringent) US. FDA standards for use in food contact
packaging and is safe for consumers. Health organizations encourage the use of single-
use food service products, including polystyrene, because they provide increased food

safety. [37]

25

All packaging (glass, aluminum, paper, and plastic - including polystyrene) contain
substances, which can "migrate," or transfer, to foods or beverages. The FDA (Food and
Drug Administration) monitors and regulates residual levels of different components in
food packaging to ensure safe packaging. [37]
Rigid thermoplastic polystyrene foam is available in densities ranging from 1pcf to over
20 pcf. PS foam can be purchased as a film, sheet and rod or as large slabs and containers
made by steam molding techniques. Foamed film and sheet can be thermoformed into
different low cost trays and for other uses in the packaging industry.
The thermal insulation properties and low cost of polystyrene foam make it competitive
with other commercial insulating materials. Because of its closed cell structure, PS foam
has excellent water resistance and low water vapor transmission. These properties make it
possible to use as a support for floating docks and for other floatation applications. The
closed cell structure and inert surface render polystyrene foams resistant to rot and mold
growth. [13]
Manufacturing of poly styrene foam
Polystyrene foam can be produced either by direct extrusion and expansion of foamable
beads and granules or by the injection of a blowing agent into the resin at high pressure,
followed by expansion at atmospheric pressure. [13]
The two basic methods of manufacturing are being discussed below.

1) Dow Chemical Process: In this method, polystyrene and expanding agent, usually

a low —boiling chlorocarbon such as methyl chloride, are blended together and

extruded. [13]

26

 

hr]

I'll
r"

2) Badisch Anilin and Soda Fabrik process: In this method the styrene monomer and
a low boiling hydrocarbon are polymerized together. The product is ground into
chips and ultimately converted into low-density foam by extrusion. [13]

The production of polystyrene foam from expandable beads is as follows;

a) Preparation of expandable beads and pellets.

b) Pre expansion of beads.

c) Conditioning of the expanded beads.

d) Molding of the expanded beads.

e) Extrusion of expandable bead and pellets to form sheet and film.

The most important and the major step in producing foam sheet is Extrusion. Three major
systems are used to produce polystyrene foam sheet and film for various applications.
Two systems involve the extrusion of expandable high molecular weight polystyrene
beads or pellets containing pentane as a blowing agent (6-7%) to produce a thin, low-
density sheet and film. Pellets are being used more as a preferred feedstock than
foamable beads because they give a more uniform feed. [13]

The third system incorporates two stages (bead preparation and extrusion expansion) into
one step. In the one step system, high molecular weight crystals of polystyrene are used
as a feedstock and produce foam sheet by addition of hydrocarbon or methyl chloride as a
blowing agent during the extrusion process. This system produces a low-density sheet
and / or film and is considered to have many economic advantages over the two-stage
extrusion of expandable beads or pellets. [13]

Polyurethane foam has one major advantage over PS and that is that it can be “put in

place” or “on the site placement”. High temperature is a requirement in the

27

 

r;

’I

manufacturing of polystyrene foam, thus on the site foaming is not feasible. PS beads
require a large quantity of heat to induce foaming, therefore, in place foaming is not
possible. However, the low cost of PS foams (6-8c/bd ft) is a strong incentive for its use.
[13]

Environmental concerns and blowing agents

Polystyrene foam products are 95 percent air and only five percent polystyrene. When
polystyrene foam packaging is produced, a blowing agent is used in the process. Most
polystyrene foam products were never made using chlorofluorocarbons (CFCs) as a
blowing agent. The very few polystyrene products that were made with CF Cs contained a
very small portion of the nation's CFC use. According to the US. Environmental
Protection Agency (EPA), only two to three percent of CFCs used in the United States in
the 19805 went toward production of polystyrene packaging products. Polystyrene
manufacturers exceeded government goals and timetables during the CFCs phase out
period of in the late 19805. Polystyrene foam products are now manufactured using

primarily two types of blowing agents: Pentane and Carbon Dioxide. [37]

Pentane gas has no effect on the upper ozone layer, although, if not recovered, it can
contribute to low-level smog formation. Therefore, manufacturers use state-of-the-art

technology to capture pentane emissions. [37]

Some manufacturers use carbon dioxide (CO; or other hydrocarbons in some cases) as an
expansion agent for polystyrene foam. C02 is a non-toxic, non-flammable gas. It does not
contribute to low-level smog, and has no stratospheric ozone depletion potential. In

addition, the carbon dioxide used for this technology is recovered from existing

28

 

00111111

increi

 

 

commercial and natural sources. As a result, the use of this blowing agent does not

increase the levels of C02 in the atmosphere. [35]

However, there is still serious concern regarding the use of polystyrene products as a
food packaging material. Due to present economic conditions, polystyrene food service
packaging is generally not recycled. Polystyrene protective packaging and the packaging
non-durables (i.e., video/audio cassettes, agriculture trays, etc.) are the primary forms of
polystyrene collected for recycling. The amount of polystyrene food service packaging
that is recycled has decreased during this period. Non-food service packaging is not
contaminated with food and other wastes, as is food service polystyrene packaging.
Therefore, it is more cost-effective to recycle. Presently, food service polystyrene
packaging is not recycled because it is not economically sustainable. It is important to
note that because of unfavorable economics, no other post-consumer foodservice

disposable material, including paper and paperboard, is recycled in a measurable way

[28].

Properties

Extruded polystyrene foam has been produced in densities ranging from 2.0pcf to 6.0pcf
in many configurations. The properties and the quality of foam sheet depend on
extrusion, pressure temperature, nucleating agent, polymer structure and other process
variables. Low densities polystyrene foam is flexible and can be laminated to paper and
high impact styrene sheet. [11]. Polystyrene foam is soluble in many organic solvents.
Polystyrene foam is water repellent because of its aromatic structure and is unaffected by

changes in RH. [28]. Figure 12 shows the basic structure of the polystyrene molecule.

29

 

 

 

 

Structure of Polystyrene

Figure 12. The basic structure of polystyrene

Since polystyrene foam is a thermoplastic, it has a well-defined softening point. The
softening point of the foam is similar to that of the parent polymer and is independent of
the volume fraction of gas present (density). The specific heat of the polymer depends on
its structure. The specific heat of the cellular composite depends on both density and
structure. The thermal expansion of the polystyrene foam mainly depends on polymer
structure and is independent of density but affected by the closed cell structure. As
polystyrene foam is an organic material, it can burn and since it is a thermoplastic it can

melt. [12]

The molecular weight (molecular size) of polystyrene determines the structure of both
extruded polystyrene foam and styrene foam beads. Decreasing the molecular weight of
polystyrene increases its sensitivity to shrinkage. In general, the following rules apply

regarding the molecular weight of the polymer.

1) Cell size decreases as the molecular weight of the resin increases.
2) The boundary between expanded beads (where the beads are firsed to beads) is

thicker for high molecular resins. [12]

30

 

J

1.47.2 Polyurethane Foam

The manufacturing of flexible polyurethane foams is a large business. Polyurethane
foams play a vital role in every day life. The foam is used in houses, cars, schools, work
places, airlines and for packaging applications. [31]

History

Mankind’s curiosity, imagination and needs have pushed research and development to
create a vast number of products. Once a basic product has been ‘invented’, then
questions about its applications, uses and economical factors are considered.[38]
Polyurethane was invented by Otto Bayer in the late 1930’s. Early in the 1940’s, some
prestigious companies such as I.G. F arben of Germany, ICI of the United Kingdom and
El. Dupont of the United States developed urethane systems for such applications as
coatings for the Barrage balloon, synthetic bristles and submarine insulation/flotation.
[38] Further development brought in new urethane products. These products greatly
expanded the markets for flexible, rigid and energy-absorbing foams. This research led
first to Poleset, then to Freon-free Poly-Set, and now our latest backfill system, Poly-

Ground. [38]

Forward Enterprises was a pioneer in the use of a rigid polyurethane foam to set direct-
embedment utility structures. Numerous companies have investigated the effectiveness of
the use of foam in areas of corrosion-protection and structural integrity for direct-

embedment structures. [3 8]

The long-term effectiveness of polyurethane foams has been established by Forward

Enterprises and by E. I. Dupont. Their research showed that partial embedment of foam-

31

 

faced panels in soil for ten years “showed negligible deterioration of the foam and of the

attached metal protected by the foam.”[3 8]

Bayer has a vast variety of case studies of urethane foam applications for protecting metal
structures from chemical attack, both above and below ground level. These show that

urethane applications counteract the porosity of masonry structures. [3 8]
Manufacturing process;

The Urethane foam manufacturing process involves a series of complex chemical
reactions. These reactions lead to the formation of many chemical bonds in addition to
the urethane groups. The two most important reactions in the manufacturing of flexible
urethane foam are the reaction between isocyanate and hydroxyl compounds (polyesters
or polyester polyols) and the reaction between isocyanate and water. The former reaction

is considered as the chain ——propagating reaction and is shown below. [13]

O

l |
R—N=C=O+R‘ -—OH—> R _ NH—C_ o_R/
(Urathane)

This reaction is common to both flexible and rigid polyurethane foam formation. [13]

An alcohol molecule first reacts with an isocyanate to form an active complex. This
complex firrther reacts with another alcohol, forming an interrnediately, which
decomposes to produce the urethane group and free alcohol. The general expression for

this type reaction may be written as follows:

32

R\NCO + catalyst —"—’ complex —* active hydrogen —’
Compounds

———> products + catalysts

The second reaction is called the water —isocyanate reaction. This reaction is responsible
for foam formation and liberation of carbon dioxide. The first step is the formation of
unstable carbamic acid, which decomposes to form an amine and carbon dioxide. The
thermal conductivity of the encapsulated gas is very important in insulation and because
of that the second step is minimized in the production of closed cell rigid urethane foam.
The blowing agent Freon is used in the later case, and the expansion of the foam is the
result of the volatilization of the fluorocarbon, caused by the exothermic isocyanate

alcohol reaction which is shown below. [13]
O

R—N=C=O+HZO ’[R NH_C_OH] ’
Carbamic acid

R— NH2 + C02

The reaction mechanism is too slow to produce economical, commercial urethane foams.
Catalysts are used to increase the reaction rate and to establish the proper balance
between chain extension and the foaming reaction. It is essential to entrap the gas (CO2)

efficiently and'to provide sufficient strength in the cell walls and struts at the end of the

33

 

TOP."
013?
Ia. .;
1 St.

531C]

hit

C]?
r‘.-

rb
v.

 

foaming reaction to maintain the structure without collapse. For rigid insulation foams, a
proper balance between exothermic chain —propagating reactions and endothermic
volatilization of the Freon blowing agents is essential. The objective is to produce a
stable foam during final curing of the structure. [13]

A second important function of the catalysts in the foam reaction is to complete the
reactions, resulting in a proper cure of the foam. Catalyst selection and concentration is
governed by the type of foam to be made, the nature of the foaming process and the foam
processing equipment and conditions available. [12]

The most commonly employed catalysts are tertiary amines and organmetallic catalysts.
[12]

Types of polyurethane Foams:

Currently urethane foam is primarily available by three types.

1) Flexible foams:
These foams are based on a propylene oxide adduct of glycerol (3000 mol.wt.). The
desired properties of the resulting foam are low density, high load bearing ability and low
set.

2) Rigid Foams:
These are made by both prepolymer and one shot processes. The one-shot method
produces low cost, high performance foams.

3) Semi rigid Foams;

Semi rigid foams are mainly used in the automotive industry where shock absorbing and

elasticity are desired. [12]

34

Manufacturing Methods

Foam properties are generally dependent upon the mode of preparation and the
mechanical processes used. In general, three methods are used:
1. Poured in place, this method is used for filling irregular voids with foam.
2. Slab stock; this method is used in applications where foam can be most
economically cut to required shape.
3. Sprayed; used in applications where field moldability is required. [13]

Foam properties vary depending on how the foam is produced [13]
Flexible foam

Polyether polyols based on alkylene oxide adducts of simple polyhydric alcohols, highly
active tin catalysts and alkyl silicon —polyoxyalkylene copolymer surfactants are the
major components of one- shot urethane foam systems. These materials and other
formulation components, together with processing variables, play a significant role in the
successful production of foam. [13]

In the one-shot system, a polyol and a diisocyanate, water, catalysts and other processing
materials are mixed. Chain extension, cross-linking and foaming reactions take places
within seconds during the gas foaming step. As the molecules line up and form a
network, viscosity increases, the carbon dioxide released is retained in the bubble and
within a few minutes the foam has turned into a solid cellular mass. [13]

The major properties of flexible foam that influence its use are [32]

35

1. Density

2. Compression
3. Sag Factor
4. Fatigue loss
5. Hysteresis
6. Tensile

7. Elongation

8. Tear

Density levels started out at around 2.0 lbs/cu. ft. The density levels were lowered as the
industry became more competitive. Currently, the most popular foam has a density of
1.2-lbs/cu. ft, though there is a trend to increase densities up to 3.5—lbs./cu. ft. In most
cases, except for high quality, high price items, it is best to maintain a minimum of 1.4-

lbs./cu. ft. density. [32]

Compression refers to a definition adopted by the American Society of Testing Materials
(ASTM). By definition therefore, compression is "the load bearing capacity of a standard
specimen indented by a circular compressor foot of 50 sq.in. at 25% deflection." The
normally accepted standard is a piece of foam measuring 25 in. x 15 in. x 4 in. thick.
Increasing the water in the formula and decreasing the amount of auxiliary blowing agent

can increase compression during the production process. [32]

Sag Factor is the compression of a piece of foam at 65% deflection divided by the
compression at 25% deflection and expressed as a pure numeric. The higher the density,

the higher the sag factor, regardless of the type of foam. The higher the sag factor, the

36

 

-l is”

better the foam. The sag factor range on most foam is from a low of 2.0 to a high of 3.0.
Any foam having a sag factor less than 2.0 is usually poor quality foam, which indicates

that it was poorly manufactured. [32]

Fatigue loss is a factor that describes what will happen to a cushion during service.
Typically it predicts what the height loss and compression loss will be after it has been in

service for some time. Inexpensive 1.32-lb./cu. Ft foam will have a height loss usually
over 2 1/2 % with a compression loss of about 30%, whereas a 2.0 lb. urethane density

foam will have height losses as low as 1/2% and compression losses as low as 10%. [32]

Hysteresis loss is relative to compression readings. The lower the hysteresis loss (higher
the resilience) the better the foam quality. No foam should have a hysteresis loss greater

than 40%. If it does, generally there is something wrong with the foam. [32]

Tensile, Elongation and tear are three material tests used to determine foam quality and
are simple to perform. Tensile strength is the force required to pull apart a piece of foam
and is expressed in pounds per square inch. Elongation is the amount the of foam will
stretch before it pulls apart. Tear strength is the force required to actually tear the foam.

The value is expressed in pounds per linear inch. [32]

Rigid foam

Rigid polyurethane foam has versatility in both directions because of its physical strength
and mechanical properties. These qualities enable it to be used in a wide variety of multi-
functional building products, which combine insulation with load bearing, sealing, impact

resistance, weight and space saving, and ease of maintenance. [13] Rigid polyurethane

37

foam provides a high level of compression and shear strength, which is further enhanced

by bonding with facing materials such as metal or plasterboard. [48]

Low thermal conductivity

Rigid polyurethane foam has one of the lowest thermal conductivity ratings of any
insulant, which allows efficient retention of heat or, alternatively, maintenance of a
refiigerated or frozen environment. [48] Effective insulation in all types of buildings is
important in the conservation of non-renewable fossil fuels. [48]

Adhesion

The adhesion strength of polyurethane foam is extremely high. This strength develops
during the short period between mixing and the final curing process. Due to its high
adhesive strength, rigid polyurethane foam can be effectively bonded to a wide range of
building facings. The adhesion is so strong that the bond strength is usually higher than
the tensile or shear strength of the foam. [48]

Compatibility/Stability

Rigid polyurethane foam is compatible with a large number of building and packaging
facings, including paper, foil, glass fiber, aluminum, plasterboard, plywood and bitumen.
These materials add to the inherent strength of the foam, which enable its use as semi-
structural panels and cladding and allowing foam to accept a variety of finishes so that it
can operate effectively as a moisture barrier in conditions of high humidity. The water
vapor permeability of rigid polyurethane foam is low and is enhanced in most building
applications by the incorporation of a moisture barrier of polyethylene film or aluminum
foil. [48] Rigid polyurethane foam provides excellent resistance to a wide range of

chemicals, solvents and oils. [32]

38

Heat and Fire properties

Like all organic building materials - wood, paper, plastics, paints - rigid polyurethane
foam is combustible, although its ignitability and rate of burning can be modified to suit a
variety of building applications and it can be formulated to meet the relevant national
regulations. [48] Rigid polyurethane foam can be used in applications which experience
exceptional extremes of temperature, from -200°C to +100°C.

Density

At low densities (e.g. 30kg/m3), the volume of polyurethane polymer in rigid
polyurethane foam is around 3 per cent. The remaining 97 per cent of the foam is gas
trapped within the cells, which provides the low themial conductivity properties. The
lightness of the foam is an important aspect in terms of transportation, handling and ease

of installation. [48]

1.47.3 Polyolefin foam

Polymer Foams are used in many different types of applications and it is hard to find an
area where they are not utilized. [28] Polyolefin Foams are a relatively recent
development compared to the other types of foam. “Olefins” or “alkenes” are defined as
unsaturated aliphatic hydrocarbons. Ethylene and propylene are the main monomers used
for polyolefin foams, but dienes such as polyisoprene are also be included. The
copolymers of ethylene and propylene (PP) are included, but not polyvinyl chloride
(PVC), which is usually treated as a separate polymer class. The majority of these foams
have densities <100 kilograms per cubic meter, and their microstructure consists of

closed, polygonal cells with thin faces...” [32]

39

 

 

r—1

‘7)
'"1

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The tremendous growth of polyolefin resins is well known to the plastic technologist or
anyone else connected with the plastic industry. From its beginning in Europe in the early
1940’s, the production of low density polyethylene has risen to phenomenal heights (over
3.7 billion pounds in 19670.1n the early 1950’s plastic foams based on polyolefin resins
first appeared commercially. Since then the market has increased, but not at the
phenomenal rate of growth that polystyrene and polyurethane foam have enjoyed. The
primary reason for this relatively slow growth is high process costs that result in an
unbalanced cost/performance ratio. [13]

History:

The earliest patent, which was issued for the preparation of expanded polyethylene, was
granted to Calendar’s cable and construction Co. Ltd. in 1945 and described the physical
expansion of polyethylene using carbon dioxide. Other patents have been issued dealing
with the physical expansion of polyethylene by using volatile liquids or gas pressurized
into the polymer melt, with subsequent depressurization to produce cellular polyolefin.
These processes were commercially not successful since they did not produce cellular
products of acceptable cost/performance ratio. However, similar methods using volatile
liquids or expanding agents have been successfully developed and commercialized. [13]
Polyolefin Foams are a relatively recent development compared to the other types of
foam. Polyolefin foam processes were developed in the 19605 and 19705. [32]

Methods of preparations:

In general, cellular plastics or composites based on polyethylene and polypropylene can

be produced by both physical and chemical methods. Each process produces a specific

40

structure that depends on polymer properties, volume fraction present in the foam and
cell morphology.[13]
At present, there are four methods involving chemical foaming agents that are used
commercially;

1. Direct extrusion expansion.

2. Compression molding using organic peroxides.

3. Pressure molding (Engelite and U.C.process)

4. Atmospheric expansion of radiation - cured sheet.

Polyolefin foam properties;
Low density chemically cross linked PE foam made by the high pressure molding
process and by atmospheric pressure expansion of procured materials has been
evaluated by Kadowaki and compared with other foams and found out that it is more
flexible, strong and semi rigid than other foams. It has shock absorbing characteristics
and water absorption is low than other plastic foams. It has a superior chemical
resistance and electrical properties. It is harmless to human beings and does not
corrode any surface metal. Polyolefin’s process ability is good. Cross-linking
polyethylene has further advantages like Very foam uniform closed cells (1-6 mils). It
has excellent esthetic appeal and acceptable heat insulation properties. Cross- linking
polyolefin has a density as low as 1pcf. and an excellent ultra violet and weather

resistance

41

1.5 MANUFACTURING METHODS FOR PLASTIC FOAMS

There are many processes to make plastic foams. Selection of a process depends on many
factors, for example
1) Quantity and production rate
2) Dimensional accuracy and surface finish
3) Form and detail of the product
4) Nature of material
5) Size of final product
Typically, plastics processes have three phases:
1. Heating - To soften or melt the plastic resin
2. Shaping / Forming - Under constraint of some kind
3. Cooling - So that it retains its shape [8]
The most common processes are injection molding and extrusion processes. A brief
overview of these processes is given below. The most universal and efficient for creating
a uniform thick and equally dense skin is the rotational molding or roto molding process.
[3 ll
1.51 Injection molding
. The most common way of producing foam parts is injection molding. Different
classification systems exist. The classification described by Fydor A.Shutov [26] into
four groups is mentioned below
1) Low pressure (LP) processes, up to 20 MPa

2) High pressure (HP) processes, up to 100Mpa or more

42

3) Gas counter pressure process and

4) Two- (or more) component processes. [26]

Basic Principle.

Plastic foam injection molding is similar to conventional injection molding. [26]

Injection Molding is the process of forcing melted plastic in to a mold cavity. The part
can be ejected after the plastic has cooled. Sometimes injection molding is used in mass-
production and prototyping. Injection molding is a relatively new way to manufacture
plastic foam. The first injection molding machines were built in the 1930's. [31]
There are six major steps in the injection molding process:

1.Clamping

An injection-molding machine consists of three basic parts; 1) the mold, 2) the clamping
and 3) injection units. The clamping unit is used to hold the mold under pressure during

injection and cooling. Basically, it holds the two halves of the injection mold together.

[31]

2. Injection

Plastic material in the form of pellets is loaded into a hopper on top of the injection unit
during the injection phase. The pellets feed into the cylinder where they are heated until
they become molten. A motorized screw within the heating cylinder mixes the molten
pellets and forces them to the end of the cylinder. Once enough material has accumulated
in front of the screw, the injection process begins. The molten plastic is inserted into the
mold through a sprue, while the pressure and speed are controlled by the screw. Some

injection molding machines use a ram instead of a screw. [31]

43

3. Dwelling, Cooling, Ejection

The dwelling phase consists of a pause in the injection process. The molten plastic has
been injected into the mold. Pressure is applied to make sure all of the mold cavities are
filled. The plastic is then allowed to cool to its solid form within the mold. The clamping
unit is opened, which separates the two halves of the mold. An ejecting rod and plate
eject the finished piece (plastic foam) from the mold. Foam formation takes place
following injection, either as a result of mold expansion or due to regression of plastic
material from the mold. [26]

1.52 Extrusion

Extrusion methods to produce plastic foams are readily available. The main advantages
of these methods include continuous and high productivity, simple equipment and
precisely sized articles. Solid and hollow profiles made of plastic foam can be
successfully substituted for wooden articles (without any further machining) and profiles
made of unformed plastics reduce feed stock consumption by 15 to 40 percent. Extrusion
is particularly economical for fabricating finished articles that do not require any

secondary processing. [26]

Basic principle

Extrusion occurs when a solid plastic (also called a resin), in the form of beads or pellets,
is continuously fed into a heated chamber and the product is carried along by a feed
screw. The feed screw is driven via drive/motor machine. Tight speed and torque control
are critical steps in producing quality product. The product is compressed, melted, and

forced out of the chamber at a steady rate through a die. Dies have been engineered and

44

machined to ensure that the melt flows in a precise desired shape. There is almost always
downstream processing equipment that is fed by the extruder. Depending on the end
product, the extrusion may be blown into film, wound, spun, folded, and rolled, and a
number of other possibilities. [40]

Plastics are very commonly extruded. Rubber and foodstuffs are also quite often
processed via extrusion processes. Occasionally, metals such as aluminum are extruded
plus trends and new technologies are allowing an ever-widening variety of materials and
composites to be extruded at continually increasing through put rates. [40]

Foam formation takes place when the polymer contains blowing agents which cause
foaming at the extruder exit (or die) [26]. Figure 13 represents the basic extrusion
machine structure.

Basic Extruder Machine

The feed screw, barrel, and temperature controller form a section of the extruder called
the plastication unit. Plastication is defined as the conversion of a thermoplastic to a melt.
This is critical to successful extrusion processes. [40]

The major components in an extruder are following.

Feed screw

The job of the feed-screw is to move the resins through the barrel chamber in a steady
and predictable manner. There are three main defined sections in a basic feed screw.

The feed zone takes resin from the hopper and conveys it along. Resin pellets encounter
friction from feed screw surfaces, barrel surfaces, and each other. This mechanical
fi‘iction provides about 85% of the required heat, so it is critical that the drive equipment,

which turns the screw, must have the HP (horse power) capabilities to overcome fiction

45

.‘l‘l

and turn the feed screw at a steady and controlled rate. Some extruders can continue to
plasticate materials long after their external heat sources are shut down. [40]
The compression zone is next. The channel depth between screw flights diminishes and.
the result is to pressurize melting resin. Friction, barrel heating, and compression
complete the melting process. Two important design parameters are associated with this
zone.
' The compression ratio is measured the channel depth at the end of this zone.
Different compounds or operating pressures require different compression ratios.
' The length of the compression zone affects the rate of compression. These two
parameters will be different for different compounds. [40]
The metering zone has a constant channel depth and primarily exists to further mix

molten resin. The end result is a smooth consistent melt with uniform temperature. [40]

Devolatizing section.

4. In some processes, a de-gassing or devolatizing section is required. This is a shorter
zone that immediately follows the compression zone (See figure 13). Channel depth is
suddenly increased, and the resulting pressure drop causes a release of gas, which can be
vented or drawn off via a vacuum pump. The remaining melt is re-compressed and

metered. The following figure 13 show a basic Extruder machine. [40]

46

 

F -_ -1

ENE.
Pr _
1! Iii

 

 

Figure No. 13

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Plastic
Hons industrial Camol Realm Hate
Fumful / Screw
u 2%; a...
Euruda
I // r Die
Paws Um Elma
Imam . Plait:
”PM | JL-IJ------:yr /Mmal
T -' ' #Dmmln
"l'""l"J_'.' ,. 511113131
_ __g___ /T
min / ] ADPuanuinr
II: MC It i .
Basic Extuder

Figure 13. Basic diagram of Extruder machine

1.53 Other processes

a) Rotational Molding
The most universal and efficient method for creating uniform thick and equally dense
foam is rotational molding [26] In this process; plastic powder is scooped into a mold.
The mold is rotated over a large gas burner. As the mold gets hot, the plastic melts and

sticks to the mold. This method is used to make large hollow objects like water tanks and

barrels.

47

b) Compression Molding
Compression molding is used for thermoset resins. Dry powder is put in a mold, which is
squeezed and heated until the plastic melts and cured. This is used for making ashtrays,
cups and plates, and some electrical switches.

c) Reaction injection Molding
In this process, two chemicals are mixed together and squirted into a mold and the
chemicals react together. This is used to they make car bumpers, some disposable cups
and plates, and meat trays.

d) Vacuum forming
In vacuum forming process a sheet of plastic is clamped in a frame and heated until it
becomes stretchy. It is then sucked into a mold. This process is used to make the inside of
your refrigerator, bath and hand basin. It is also used to make a lot of packaging for
cosmetics, chocolates, biscuits, some yogurt containers and disposable cups.

e) Fabrication
Some thermoplastics are fabricated like sheet metal. Sheets of plastic are cut to the
desired shape. They can then be folded by heating a narrow line through the plastic.
When it is soft, the sheet will bend along the heated line. Sheets can be joined together by
gluing, or by welding. The joint is heated with hot air and a thin filler rod is forced into
the gap. These fabrication methods are used to make acrylic signs and displays, and
industrial tanks and equipment. They can also be used to manufacture laboratory fume

cupboards and exhaust fans. Thin flexible plastic sheets are used for making folders,

48

ulz:

 

 

 

wallets, swimming pool liners, inflatable toys and raincoats. The seams are welded using
ultrasonic vibration.

f) Styrene Foam.
To make blocks of styrene foam, or complicated shapes like a cycle helmet, pallets are
scoop into a mold and heated with steam. The steam makes the pellets swell and stick

together. [1]

49

CHAPTER 2

MATERIALS AND METHODS

Chapter 2 covers the material and methods section for the research “ Performance
properties of biodegradable foam (Green Cell® foam) .The following M&M are
presented

2.0 Twin Screw extrusion process

2.1 Cushioning characteristics

2.2 Dimensional stability

2.3 Moisture sorption

2.4 Thermal insulation

2.0 Green Cell® Foam is produced by twin Screw extrusion process
Materials:

The type of starch used was hydroxypropylated high amylose cornstarch (70%
amylose content). The starch was purchased from National Starch and Chemicals
(Indianapolis, IN), under the trade name of HYLON 7. The inherent moisture content of
the starch was 11.2% under ambient conditions.

Water was used as the plasticizer as well as the blowing agent. Water content was
maintained at 7-10% of the starch used. Talc (Magnesium Silicate), used as the

nucleating agent, was obtained from Luzenac (Ontario, Canada). It has a specific gravity

50

 

 

 

:1

7:1

 

of 2.76 and a bulk density of 150 kg/m’. The tale content was maintained at 1% for all the
experiments.
Poly (hydroxyamino ether) (PHAE) is an additive, which offers the adhesion and
durability of epoxy resins with the flexibility and process ability of thermoplastic resins.
PHAE was purchased from Dow Chemicals (Midland, MI), under the trade name BLOX
110. PHAE has a melt temperature of 75°C, and is produced by reacting liquid epoxy
resin (LER) with hydroxy functional dinucleophilic amines and resorcinol diglycidyl
ethers (RDGE) [45].
Experimental Setup:
EQUIPMENT FOR GREEN CELL

1) Thick material. Twin Screw Co —Rotating Food Extruder: Wenger TX-80. (D=80

mm, L/D=20)

2) Positive displacement pump: For injecting water.

3) Screw Feedersl&

4) An Annular Die: 2.5mm width

5) Down stream equipment for cutting and rolling or laminating foam sheets.

6) Figure 2 represents a process flow diagram of making Green Cell foam.

The experimental setup used in this study was a twin-screw extrusion system (fig. 14).
The twin-screw extrusion system consisted of an extruder driver with a speed control
gearbox, a Werner Pfleiderer ZSK-3O twin-screw co-rotating extruder with a screw
diameter of 30 mm, an MD of 32, a positive displacement pump for injecting water into

the extruder, accurate single-screw feeders for feeding starch, and PHAE and talc could

51

mmi

WOUT

{UHC

8351

The

We.“

3m.

mhl

 

 

be fed individually or as a mixture. A cylindrical filament die 2.7mm in diameter and 8.1
mm in length, with a cooling sleeve was assembled to the extruder. The sensors were
mounted on the die to measure the temperature and pressure of the melt. A high-speed

cutter was used to get cylindrical foam samples of required size.

Basic principle

The foam sheets are being produced on an industrial scale twin-screw food extruder,
Wenger-80, having a screw diameter of 80mm and an L/D of 16. An annular die of width
2mm is used. Talc is not used in the production of starch foam sheets in order to get the

minimum density product. Also, the addition of talc rendered the product more brittle.

Water

 

Figure 14. Process Flow Diagram of Green Cell Foam.

[45]

52

of

 

 

2.1 Cushioning Characteristics of Green Cell® Foam.

The cushioning characteristics of Green Cell Foam were deterrnrned, and compared

with the G values of different plastic foams commercially available. The effect of relative

humidity and time on the G value of Green Cell® foam was also evaluated.

2.11 Instrumentation (Lansmont drop tester)
G value of one and two inch thick GCF were determined using Lansmont drop tester,
(Monterey CA) at the controlled temperature 22°C and 50% RH .The instrument consists
of the following components.

1) Instrumentation and shock sensors

2) A dropping platen
The dropping platen must have a mechanism to attach additional mass for adjusting its
total mass to a desired value.

3) Reaction Mass
Reaction mass would be attached to the testing machine. Reaction mass would be
sufficiently heavy and rigid so that no more than 2% of the impact acceleration is lost to
the reaction mass while conducting dynamic tests. The reaction mass must be in contact
with the ridged impact surface so that the two bodies move as one.

4) Accelerometer
The accelerometer is a data storage system and is required to monitor acceleration versus
time histories. The instrumentation system needs the following minimum requirements.

Frequency response range from 2H2 or less to at least 1000Hz.

53

 

l:

71.

Ci.

ffi

 

 

Accuracy reading to within 5 % of the actual value

Cross axis sensitivity less than 5 % of full scale, and the instrumentation are required to
measure the impact velocity to an accuracy of

i 2% of the true value.

Test material

KTM Industries, Inc. develops, manufactures a bioplastic Green Cell® Foam. The type of

starch used was hydroxypropylated high amylose cornstarch (70% amylose content). The

. . . . . ®
inherent morsture content of the starch was 11.2% under ambient conditions. Green Cell

Foam is produced by twin Screw extrusion process. 25 pieces each of Green Cell® foam
having dimensions of 8”x8”x1” and 8”x8”x2”were used.
20 pieces each of Green Cell® foam having dimensions of 6”x 6”x 1” and 6”x 6”x 2”

were used

2.12. Methods.

Conditioning

The Material was conditioned at standard conditions (25°C and 50% relative humidity)
prior to do the cushion testing. [3]

Determining dynamic shock cushioning characteristics.

The specimen was loaded onto a rigid plate or onto the machine platen to 0.025 psi
(17.55 kg/mz) on the top surface area. After a 30 sec interval, the thickness to an accuracy
of 1/32 inch was measured by averaging the thickness measurements of the four corners

of the specimen. This value was recorded as the specimen thickness.

54

The top surface area of the specimen was measured with an apparatus yielding values
accurate to 1/32 in. The mass of the specimen was measured with an apparatus yielding
values accurate to 30g. [3]

The test specimen was centered on the impact surface face and the platen was positioned
to strike the cushion on its top surface area. The specimen was subjected to a series of
five drops at a pre-deterrnined static loading and impact velocity allowing a minimum of
1 min between each drop. A complete acceleration time record for each drop was
recorded and the impact velocity of the platen was measured just before impact to ensure
that it was representative of the impact velocity equated to the desired free drop height.
To obtain dynamic data for a given cushion, it is necessary to repeat the five test drops on
new specimens varying some aspect of the test such as static loading impact velocity or
cushion thickness. [3]

2.13 Calculation

The density of a test specimen was calculated using the following equation.

D = (3.81x M)/ (leszT)

D= density (1b /ft3)

M = mass of the specimen (g)
L1 = length of the specimen (in)
L2 = width of the specimen (in)

T = original thickness of the specimen in

55

For free fall height, the following equation was used

H = Vi2 /2g

and impact velocity can be calculated using the following equation.

Vi = \/2gh

H = free fall drop height (in)

Vi = measured impact velocity in/sec

G = acceleration due to gravity 386 in/sec2

Dynamic set can be calculated using the following equation

Dynamic set % = [(T-F)/T] x 100

T = original thickness of the specimen (in)

F = thickness of specimen after test (in) [3]

2.14 Effect of % RH and temperature on C values

Method.
To determine the effect of relative humidity on GCF ’s G value, 2- inch thick material was

tested to determine its G value according to ASTM standards D-1596. Seven pieces of

GCF were determined based upon 1St impact and then these seven pieces of Green Cell®

56

foam were held under seven different relative humidity conditions at 30° C for two
months.
After two months, GCF pieces were again tested to determine their G value at the same

static load, drop height and weight. _

2.15 Effect of Time on G values.

1-inch thick material and 2-inch thick material were tested at different times during three
months of storage. The G value of l-inch foam was 80.80(average) initially. The same
batch of material was then tested after two months at ambient conditions (humidity and
temperature conditions varied according to the external weather conditions). 2"° set of
fresh material was then received and was tested again to determine the G values at same
the drop height, bearing area of foam and static load. Fresh material had a G value of

80.804(average of five drops).

57

Ed
I)

 

 

 

 

2.2 Dimensional Changes

Dimensional changes (length, width and thickness) of GCF and net weight loss /gain of
the product (Green Cell®) at 30°C/ several different humidity conditions was determined.
An experiment was set up using samples of Green Cell® foam and saturated salt
solutions. Salt solutions were prepared according to ASTM standard E104 [2]. Detailed
can be seen in appendix E.

Dimensional changes and weight loss/gain were measured periodically until equilibrium

conditions were achieved. Effects of ambient conditions on GCF were also determined.

Materials and Methods,
Materials.
Dimensional changes at different relative humidity (%RH) conditions and
30°C
I 14 pieces of Green Cell® Foam having dimensions of 2”x 2” x 1”
I Seven RH chambers
I Digital vemier caliper (supplies)
Material behavior at ambient conditions
I Three pieces of Green Cell foam having a dimension 5 of 8” x 8”x 2” were used
to examine the Green Cell® behavior at ambient conditions.
Change in thickness under load
I Several pieces of Green Cell® foam having a dimensions of 8”x8”x2” and

8”x8”x1” were used. to examine the effects in thickness under load conditions.

58

I Vernier caliper
I Dematerialized water
I 8 one gallons of bottles

I 8 wooden blocks 8”x 8”x '/2”

Methods:

Dimensional changes at different relative humidity (%RH) conditions and 30°C.

Salt solutions were prepared according to ASTM standard E104 (Appendix E). Green
Cell® foam material was cut into 2x2xl inch pieces. The dimensions were measured
using a digital vemier caliper and weight was measured using an analytical balance. All
the pieces were placed into the HDPE buckets containing different salt solutions to create
specific humidity conditions. All the HDPE buckets were placed inside an environmental
chamber at 30°C.

Each piece was marked as to its length width and thickness. Dimensional change in each
piece was measured by vemier caliper and weight was checked by analytical balance
each day for the first week and then at a time interval of 1-3 days until the weight of the
product became constant. Each piece was marked at one specific location when taking the
first reading and all subsequent readings were taken using this as reference. One piece of
material was removed from the bucket and measurements, at a time, measured quickly as
the product is sensitive to moisture. Latex gloves were used to avoid any contamination

or hand moisture.

59

Material behavior at ambient conditions.

1” and 2” Green Cell® foam was kept under observation in. the experimental lab where
temperature and relative humidity conditions change according to the weather conditions

for about three months.

The Change in thickness of Green Cell® Foam under Specific load

a) At 50%RH and 25°C

b ) At ambient conditions

Two sets of experiments were conducted to determine the change in thickness under load.
One set of experiments was conducted in a room where temperature and relative
humidity conditions varied according to ambient conditions. Another set of experiments
was conducted in a controlled conditioned room where temperature and relative humidity
conditions were maintained at 25°C and 50% RH. One gallon Plastic bottles were filled
with water and placed on top of the Green Cell® foam pieces which had been covered
with wooden blocks. Wooden blocks were placed over the Green Cell® foam to provide
uniform weight distribution over the foam pieces.

Thickness of GCF was measured periodically with using a digital vemier caliper.

Thickness was determined at the same location each time to minimize error.

60

2.3 Sorption isotherm
Sorption isotherm was developed at different RH% conditions and net weight changes at

30°C and different RH %conditions were measured.

2.31 Sorption isotherm at different %RH and 20°C,25°C and 30°C

2.32 Net weight changes at 30°C and different %RH conditions

2.31 To determine the moisture sorption isotherm of the product at 20°C, 25°C
30°C

Empty aluminum dishes were weighed and approximately 0.5-2 grams of product was
added to each dish. Green Cell® foam was cut into small pieces to increase the surface
area of the product to allow it to reach equilibrium conditions. Dishes were reweighed.
Triplicates were prepared for 7 or 8 humidity conditions. Aluminum dishes containing
GF C were then placed over saturated salt solution prepared at different relative humidity
conditions. Three replicates were prepared. Storage temperatures used were 20°C, 25°C
and 30°C.Weight readings were taken every day for the first week, then at a time interval
of 1-3 days until the weight of the product became constant. The equilibrium moisture

content of the samples, was determined using the following formula:[18]

Me

We

 

W,(M,+l)-1

Where,

61

We, Equilibrium or final weight of the product
Wi_ Initial weight of the product

Mi. Initial moisture content of the product

Sorption isotherms were then plotted at the three temperatures used GCF.

The GAB model was used to obtain the best fit for the product. Graphs were plotted
between aw/Me and Me to obtain various constants (a, [3, y) for each temperature to
develop the GAB model. Comparison was made between experimental values and the
GAB model values. RMS values were then calculated. The best fit was determined using
the RMS value, the lower the RMS value, the better fit.

Determination of the Initial Moisture Content (Mi) of the product by

Gravimetric method:

Initial moisture content was determined using the AOAC official method 934.06. as
modified. [4]

Three empty aluminum dishes were weighed and 1-2grams of product added and
reweighed. The product was then placed in a Laboratory National vacuum oven at 75-
80°C under 22-25in Hg for 8-9 hours to determine the moisture loss from the product.

Initial moisture content of the product (dry basis) was then calculated using the following

 

formula: [4]

Initial Moisture content of the product = Wi-Wd x 100
Wd

Where,

62

W: = initial weigh of the product

Wd = Final weigh of the product

2.32 Net weight changes

Salt solutions were prepared according to ASTM standard E104 [2]. Detailed calculations
can be seen in appendix E. Green Cell® foam material was cut into 2 x 2 x 1 inch pieces.
The weight was measured using an analytical balance. All the pieces were placed into the
HDPE buckets containing different salt solutions to create specific humidity conditions.
All the HDPE buckets were placed inside an environmental chamber at 30°C.

Weight was checked by analytical balance each day for the first week and then at a time
interval of 1-3 days until the weight of the product became constant. One piece of
material was removed from the bucket and measurements were taken quickly to avoid
extra moisture absortion/desorption. Latex gloves were used while taking the reading to

avoid any contamination or hand moisture.

63

2.4 The package insulating ability (R -Va1ue) and bulk density of Green Cell®
foam.

A modified version of ASTM D3103 (ice melt method) [10] was used to quantify the
insulating ability of a package by specifying a means for calculating its thermal resistance
(R -value). Density of the foam was calculated .In order to calculate the R- value R-
value, a cooler measuring 11 x 10 x 9 ”8 inches was fabricated from GCF and used as the
test specimen. EPS and Green Cell® coolers were made to have the same dimensions. To
compare the R- value of Green Cell® with EPS, experiments were performed at the same
time, in the same environments with the same equipment and the same amount of ice.
Experiments were performed in two different environment, 30°C and 80% RH and 25°C
and 50% RH. [5 a ]
2.41 Materials.
I For density calculations three pieces of Green Cell® foam having dimensions
8”x8”x2” and three pieces of Green Cell® foam having dimensions
8”x8”x 1 ”were taken.
I Ruler
I Analytical balance
I Ice Melt method [10]
Regular cubed ice or crushed store ice can be used. The amount of ice was used was
based on the available inside volume of the coolers (EPS and GCF). Approximately, 1/2
of the inside volume was filled with ice.

I Package:

64

I Green Cell® cooler. A GCF cooler was made by using couurugated fiberboard as
a frame. Hen placed into the fiberboard Slabs of GFC were then placed into the
fiberboard box.
I b) EPS Coolers:
An EPS cooler was made of l l’Q-inch thick EPS foam.
I Bucket:
Plastic buckets was used the coolers it. Metallic buckets can interfere with the calculation
of the package R-value by providing a reflective surface not associated with the coolers
itself. Same size and same color buckets were used for GCF and EPS coolers.
I Duct tape or any sealing adhesive tape:
Sealing is a very important step. Stray air currents can flow in and out even through the
smallest of openings. This can carry enough heat to render the best insulator ineffective.
I Ruler: to measure the dimensions.

I Thermometer: graduated cylinder or weight scale [10]

2.42 Methods

Density of the Green Cell® Foam:
Density of Green Cell® foam were calculated .Two Green Cell® foam dimensions were
used to determine it’s density, 8”x8”x2” and 8”x8”x1”.
Weight of the material was measured using an analytical balance. Length, width and
thickness were measured using a measuring tool (ruler). Averaged density was calculated

from three replicates.

65

Calculation

The density of the specimen was determined according to the following formula

D = (3.81x M)

 

(leszT)

D: density (lb /ft3)

M = mass of the specimen (g)
L1 = length of the specimen (in)
L2 = width of the specimen (in)

T = original thickness of the specimen in

R-value

Ice Melt method.

This test closely resembles the situation in which an insulating container would be used
be used & it is also similar ASTM D3103: Standard Test method for thermal Insulation
Quality of a Package [10].

In the ice melt test a quantity of regular cubed or crushed ice is placed in a non— metallic
bucket (preferably plastic made of HDPE) inside the package. The package was sealed
with duct tape to avoid any air circulation from the outside environment into the package
or vice versa. This assembly was stored at 50%RH and 25°C (77°F). A second trial was

done at 80% RH and 30°C (86°F). The amount of ice used, was selected to fill at least

66

half of the available volume. The ice was then allowed to melt for several hours, after
which the bucket was removed, and the water drained out and discarded. This was a
preconditioning procedure intended to ensure that the ice was uniformly at its melting
temperature, (32°F) before the actual test would begin. This then maintained a constant
temperature difference across the package wall.

Metallic buckets must not be used because they could interfere with the calculation of the
package R value by providing a reflective surface not associated with the package itself
[10].

The buckets were then placed back inside the package near the center and the package
was sealed with tape to make it relatively airtight. Sealing is very important. Stray air
currents may flow in and out through the smallest of openings and carry enough heat to
render even the best insulator ineffective [10].

The day and time were recorded and the package was immediately placed in a draught
free constant temperature environment, at 50% RH and 25°C, on a shelf or other surface
off the floor. The package was then allowed to sit in this environment for at least one day
and possibly two or three days depending upon the package. The aim is to get most, but
not all, of the ice to melt. The experiment was replicated three times as specified in
ASTM [10].

The day and the time were recorded at the end of this time period. The box was opened,
the bucket removed, and the water was drained out. The water collected during this
procedure was weighed, since it takes 144 Btu of heat to melt 1 lb of ice (the latent heat).
The heat transfer rate in Btu fh into the package was the melt rate multiplied by the latent

heat. This can then be depicted as a system R- value using the following formula.

67

System R- value = (box area) (Temperature difference)

 

(Melt rate) (Latent heat)

The R- value mainly depends on the wall construction, and not the size of the package
and is a reciprocal of the effective coefficient of heat transfer. The box area term is the
inside surface area of the package. The temperature difference term is the temperature
difference between the outside air and the ice. The melt rate term is the rate at which ice
melts during the experiments and is equal to the weight of the water (melt ice) collected
divided by the exposure time.

The same experiment can be done with dry ice (solid C02). Since dry ice goes directly
from a solid to a gas, the melt rate would be calculated as the difference between the
starting & ending weights of the block of dry ice, divided by the exposure time.

The temperature difference must be based on an ice temperature of —180.4°F instead of
32°F, & latent heat of 240 Btu/lb instead of 144 cal. Whichever method is used the R-
value should be the same [10].

The summary of research on the performance properties of Green cell Foam (GCF) can

be seen in figure no. 1 5

68

Research overview

 

Performance properties of Green Cell
U ' E B F to

31'

       

a.

 

Cushioning Dimensional Sorption R- Value
Effects Changes Isotherm

G Value at 25“C and Dimensional Different R11 and R-Valuc at 25°C and
50%RH Changes at 20.25 50% R11
Different R11 and and 30"C
30°F

Comparison of GCF Atmospheric Effects Net weight Changes R- value at 30“(‘
with at And 86% RH
other plastic foam 30C and different
"AR"

Time Effect on G Changes in Ihickness
l \"alue under load

%RH and At
Temperature 50%RH
Effect on (i \alue And 25"('

Atm
Fond.

 

Figure No 15. Overall Research overview of the Performance properties of Green Cell

Foam.

69

CHAPTER 3

RESULTS AND DISCUSSION

The results and discussion are divided into different sections as follows.
3.1 Cushioning characteristics
3.11 G value at 25°C and 50%RH and comparison of G values
3.12 Time Effect on G values
3.13 Effect of relative humidity on G value
3.2 Dimensional stability
3.21 Dimensional changes at different relative humidity (%RH)
conditions and 30°C
3.22 Material behavior at ambient conditions
3.23 Changes in thickness under load
3.23-a at 50%RH and 25°C
3.23-b at ambient conditions
3.3 Moisture sorption
3.31-a Sorption isotherm at different %RH and 20°C, 25°C and 30°C
3.3 l-b Net weight changes at 30C and different %RH conditions
3.4 Thermal insulation
3.41 Density calculations
3.42 R- value at 25C and 50% RH

3.43 R- value at 86%RH and 30C

70

Results and Discussion

3.1 Cushioning Characteristics of Green Cell Foam.

The cushioning characteristics of Green Cell® Foam was determined and the G values of
Green Cell® foam were compared with the G values of different plastic foams
commercially available. Effect of relative humidity and time on the G value of Green
Cell® foam was determined.

Packaging designers face many challenges in predicting the performance of cushioning
materials, when designing protective package .The prime objective is to choose the
proper cushioning material that will protect the product from the hazards of the
distribution environment, such as shock and vibration. It is also to achieve the most cost
effective package. Classically, shock attenuation characteristics of cushioning material
have been considered a material characteristic. Shock attenuation is commonly presented
as a cushioning curve, which is a plot of peak acceleration in G’s vs static loading and is
used to compare and qualify materials. [41]

Peak acceleration is represented by G; such forces are basically a shock of very short
duration, and high deceleration. [42]

By definition, deceleration is the rate at which an object slows down, and can be written
as

G = deceleration

 

g

71

G is a dimensionless number and important in designing a package because it is
proportional to the impact force on the product and impact force is what damages the
product [42].

Fundamental information about the product is necessary to develop a precise and low
cost package for product protection. Thus, fragility level is the most vital parameter to
determine. [41]. Gorman [41] defines fragility as “The maximum acceleration and
velocity change the product can withstand before damage occurs”. Typical fragility levels

for different products is presenting in the following table 2 [42]

 

Extremely Missile guidance systems, precision aligned test 15-25 G’s

fragile instruments.

 

Very delicate Mechanically shock mounted instruments and 25-40 G’s

electronic equipment, Disk drives.

 

Delicate Aircraft accessories, Computers, Laptops, Flat 40-60 G’s

Panel monitors, Standard Monitors, Printers,

 

 

 

Scanners.
Moderately Television Receivers, Aircraft accessories 60-85 G’s
Delicate
Moderately Major Appliances 85-1 15
Rugged G’s
Rugged Industrial Machinery 115 G’s

 

 

 

 

and above

 

Table 2. Typical Fragility Levels for Different Products [42]

72

This information is then charted to form a damage boundary curve (DBC). A Damage
boundary curve is drawn between the critical. velocity change (AV) and critical
acceleration (AG) and is obtained from drop tests. From the DBC curve, the fragility of
the product can be determined. [11.].

Classically, cushion curves are used to identify a material thickness and loading range
based on a pre-determined drop height and required acceleration level. By comparing
cushion curves of various materials (generated using the same test method), a cushioning
material with the least amount of surface area and thickness can be chosen [41].

Cushion characteristics can be determined by plotting cushion curves. A cushion curve is
a graphic representation of a transmitted shock (G) over a variety of static loading
conditions (psi or kg/m2) for a specific cushioning material thickness at a specific
equivalent free fall drop height [11].

G values of the Green Cell® Foam (two inch and one inch thickness) were determined at
different static stresses (psi) by keeping the same drop height (24- inches) and then
comparing these G values for the same thickness and drop height with commercial foams
(tables 3 and 4).

It was also found that GCF could not bear the total reaction mass 63.3le. Green Cell®

Foam tore as shown in the figure 16.

73

 

Figure 16. Material damage at 1.75psi, determine G value, 1St impact

Table 3: Comparison of the G value of Green Cell Foam® two inch thick with the G
values of commercial materials.* (2” thickness,24 in Drop height) [5-a]

Static

 

74

The G values of commercial material were taken from the literature [15]. At lower static
stress, Green Cell® foam had low G values as compared with the other materials while at
higher static stresses the material behave about the same as the market competitors [5-a].
This results shows that G values of 2-inch thick Green Cell foam is competitive with the
other foams as for as G values are concerned. Graphical representation of the comparison

of the G values can be seen in figure 18.

G vs ststic stress(2-inch thickness)

 

45
40 .-.. -- -- ..-v. .WJ. ‘l

35 __- , ’ We .1 ,_ , --
30 T T T" ”‘27" "WT“ ":lggE'Gg
25 — . - -- -_ -- ,_----,_ , , .

20 -—--— -, W — .-
15 -~ , - ~ .

1° [*GCF -ffi, . M ]

G's

 

 

 

 

0 0.5 1 1 .5 2
Static stross(psi)

 

 

Figure 17. G values of Green Cell® foam Vs Static Stress (psi) * 2-inch thick GCF

75

Comparison of G values 2" thickness

 

 

 

 

 

 

 

 

 

80

70 ]—

°° ’” +PE ,G's
i; 50 ~ -—— +GC ,G'e
o +EPS,G'e ,
2 40 -_
g EPE(Dow)
o 30 r _ +EPE(Arco) ‘

20 i- - - _ - -__ - __-_ _ ,_. _ _-O—EPE(D9wL

1o

0

o 0.5 1 1.5 2
Static Stress(psi)

Figure 18 Comparison of the G values of 2 in thick GCF with the G values of commercial
materials. * (2” thickness 24” Drop Height)

1-inch thick Green Cell® foam was also tested to determine its G values and these values
were compared with the G values of other foams.

At lower static stress, Green Cell® foam had lower G values as compared with other
materials, but at higher static stress, had higher G values as compared to the competititive
foams [5-a]. This comparison can be seen in table 2 and graphical representation is

shown in figure 19.

76

Table 4. Comparison of the G values of Green Cell® foam with the G values of other

commercial materials(l” thickness 24” Drop Height).

 

 

 

 

 

 

 

 

 

 

 

 

PE (1.25pcf) (220ch (2.2pcf) (2.2pcf) Green Cell
Static stress G value EPS EPE(Dow) EPE(Arco) Dow (3.4pcf)
S.S psi PE ,G's EPS,G'5 EPE(Dow) EPE(Arco) EPE(Dow) GC ,G's Stdev
0.2 120 116 81 92 100 56.6 4.6
0.355 105 87 65 81 64 63.0 1.1
0.403 73 8O 63 73 63 72.0 3.1
0.8 64 63 59 95 60 81.0 1.2
1.305 75 65 90 73 117.0 0.0
1.44 83 70 97 80 116.0 4.5
1.58 90 78 105 83 117.0 2.0
1.722 105 84 110 87 131.0 1.6

 

 

 

 

 

 

 

 

Graphical representation of the comparison of the G values can be seen in figure 19.

77

 

Comparison of 6 values 1" thick foam

 

 

 

 

 

 

 

 

140
120 .
100 . - PE .6'3
9 —I— GC ,G's
9 so -
g +EPS,G'e
E 60 , EPE(Dow)
a —I— EPE(Arco)
4o 4 -_- —— - — W W W W- - |W3—EPE(Dow)7
20 a. _ _ - _ _ -- #_ 7 + W- __--
0 W
0 0 5 1 1 5 2

Static Stross(psi)

F ig19. Graphical representation of the G value of ‘Green Cell® foam with the G values of
other commercial materials. *(1” thickness 24” Drop Height)

G vs static stress(1-inch thickness)

 

140.0
120.0 -—er -__- WWW W a O ‘
100.0 -W W -W—- __,-_, .- .. _ . _------

80.0 -_ .._-.--- _.‘ __ -----,,--___- f -
. I
60-0: ---- —---W W — _-_-_- .e-__- m

40.0 W WW . . WWW -.-_.-_-_--
20.0 W- __ - - .- ..__-_ . ________._. _-
0.0

 

G's

 

 

 

 

 

 

L Static Stress (psi)

 

Figure 20. Graph between G values of GCF Vs Static stress (* l-inch thick GCF)

78

3.11 Effect of Time on G values:

The G values of GCF decreased with time.

l-inch thick material and 2-inch thick material were tested at different times during three
months of storage. It was observed that the G value of l-inch foam was 80.8(average)
when material was received. The same batch of material was tested two months later. The
material was kept in an ambient air-conditioned environment where humidity and
temperature conditions varied according to the weather conditions. The G value was
found at that time to be 51.6. A 2nd set of fresh material was then received and tested to
determined the G values at same the drop height (24 inches), bearing area of foam (64
inz) and static load (51.0 lbs). Static stress was kept constant (0.8lpsi). The fresh material
had a G value of 80.8(average of five drops

This behavior can be seen in table 5.

Table 5: Comparison of G value of *GCF with respect to time
Thickness 1- inch Green Cell® foam

 

 

 

 

 

 

 

 

 

Type of
material C value s.dev
Fresh material
lSt set 80.0 2.2
Two months
later-1St set 51.7 3.3
Fresh material
2nd set 50.3 1.7
Two months
later-2nd set 80.8 2.2

 

79

Similarly, two-inch thick foam was tested and showed the same pattern. The first set of
fresh material was tested and had a G value of 34.9 with the st. dev of 3.8. It was then
kept at ambient conditions where temperature and humidity conditions varied according
to the weather conditions. Two months later it had a G value of 24.2(st dev. 1.3). A 2"d

set of fresh material was tested at the same drop height (24 inches), bearing area of foam
(64 inz) and static load (51.001bs). Static stress was kept constant (0.81psi).

Fresh material had a G value of 35(average of five drops) with the st.dev of 1.02.

3.1 2 Effect of relative humidity on G value:

Relative humidity had a significant effect on the G values of Green Cell® foam. Green
Cell Foam® at 11% and 43% had an increased G value (from 39.97 to 51.84) and (from
43 to 45.2) [S-a]. No significant increase in weight was observed.

There was no distinct change observed in G values at 54%, 75%and 86% RH.

But at 89%RH and 96% RH, an increase in G values were observed along with
Significant increase in weight [5-a]. Expansion in the thickness direction was observed at
75% RH, 30°C. This behavior can be seen in figure 20. Fungus was also observed on the
material at 89% RH and 96% RH, contracted significantly and lost its shape. The bearing
area of the Green Cell® foam decreased. As toughness and bearing area decrease, G
value increases. These results are shown in the following figures (21-30) and tables. (6

and 7) Detailed calculations and material physical changes are shown in appendix A

80

Table 6. G value and change in weight (Aw) of Green Cell® foam with respect to time.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

if Two
Fresh Two months Fresh months
material later material later Aw
s.no RH G value G value wt. wt. met wt. gaim
% (g) (g) (g)
1 11 39.97 51.84 51.62 52.68 1.06
2 43 38.58 45.21 52.65 52.64 -0.01
3 54 32.18 38.29 54.58 54.7 0.12
4 75 39.22 36.53 51.86 53.96 2.1
5 86 32.9 37.25 56.34 62.03 5.69
6 89 39.15 50.63 51.51 60.59 9.08
7 97 38.42 76.77 52.38 67.31 14.93

 

 

 

Table 7: Comparison of impact time and impact velocity before and after keeping the
material at specific %RH conditions.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

l—\ Fresh Two months Two months
material later Fresh material later
JJlo RH time time velocity velocity
% (ms) (ms) (in/sec) (in/sec)
l 11 22.8 17 177.25 182.63
2 43 23 18.1 170.57 174.4
3 54 25.2 21 158.19 171.59
\4 75 22.9 22.6 172.57 169.08
\5 86 25.8 18.8 164.47 153.64
\6_ 89 22.1 16.4 169.92 163.43
\7 97 22.8 12.4 169.86 184.1

 

81

 

Figures 21-30. Show the Green Cell Foam kept at 25°C/ 50%RH, at 30° C 75% RH,30

°C /84%RH,30 °C /89%RH and 30°C /96% RH.

25°C and 50% RH 30°C and 75% RH

 

Figure 21 (Front view) Comparison of Green Cell® foam kept at 25°C, 50%RH and
30°C, 75% R

 

25°C and 50% RH 30°C and 75% RH

Figure 22 (Side view) Comparison of Green Cell® foam kept at 25°C, 50%RH and 30°C,
75% RH [5'3]

82

25°C and 50% 30C and 84%
RH

Figure 23. (Side view) Comparison of Green Cell® foam kept at 25°C, 50%RH and
30°C, 84% RH

 

 

Material became soggy, lost its shape and

And showed marks of deterioration

 

83

Figure 24 GCF kept at 84% RH and 30°C

25°C and 50% 30°C and 89%
RH RH

 

 

Figure 25 (Front View) Comparison of Green Cell® foam kept at 25°C, 50%RH and
30°C, 89% RH [5-a]

Fungus growth

 

84

Figure 26. Material kept at 89% RH and 30°C

l 25°C and 50% RH 30°C and 89% RH

Figure 27 (Side view) Comparison of Green Cell® foam kept at 25°C, 50%RH and
30°C, 89% RH

 

. 2." i
25°C and 50% RH 25°C and 50% RH

 

85

Figure 28 (Front view) Comparison of Green Cellq‘ foam kept at 25°C, 50%RH and
30°C, 96% RH

Fungus Growth

 

Figure 29. Material kept at 96% RH and 30°C

25°C and 50% RH 30°C and 96% RH

 

Figure 30 (Side view) Comparison of Green Cell® foam kept at 25°C, 50%RH and
30°C, 96% RH

86

3.2 Dimensional stability

The dimensional stability of Green Cell® Foam was determined. Dimensional changes
(length, width and thickness) and net weight loss /gain of the product (Green Cell®) at
30°C and different humidity conditions were determined.

Dimensional changes at 30°C at several % RH conditions

A 4.3-6.0 kg weight was placed on the material and changes in thickness were observed
periodically. An experiment was set up using samples of Green Cell® foam and saturated
salt solutions. Dimensional changes and weight loss/gain were measured periodically
until the equilibrium conditions reached.

Change in thickness:

The most expansion accrued at 75% and 84% and this behavior can be seen in Figs 21-
25. The material expanded 0.400 inches during 408 hrs at 84% RH and 30°C, and 0.332
inches during 408 hrs at 75 % RH and 30°C [5-a]. Detailed calculations are shown in
appendix B-Dimensional Changes.

Negligible change in thickness was observed (0.03-0.075 inches) at 11%, 43% and 56%
RH% at 30°C.The material contracted slightly ((—0.053, - 0.055) inches) at 89%RH and

95% RH%.

87

,_ ka Saw-(3'4 F” *9 7°,
” a “z‘aixf 7m MN
Ti gi i.” ”‘15-'11“:

 

Figure 31. Comparison of GCF maintained at 84% RH/30°C and 50%RH /25°C.
(Front view)

84% RH/ 30°C

‘n' i -. RH 8117.
_ "WME One. WEEK!

 

Figure 32. GCF maintained at 84% RH/ 30°C and 50%RH /25°C
GCF pieces were compared afier one week of time period. (Side view).

88

"Vb

50% RH and 25°C 75% RH and 30°C

Figure 33. Comparison of samples maintained at 75% RH/ 30°C and 50%RH/25°C.
(Side View)

 

 

50% RH and 25°C i 75%RH and 30°C

 

Figure 34. Comparison of samples maintained at 75% RH/ 30°C and 50%RH /25°C.
(Front View)

89

 

 

 

 

 

 

 

 

 

 

Net Change in thickness

0.6000
:5. 0.5000 w W W _
3 04000 _ “ml-‘5 .. T 11%RH
E ' I ‘ “'. ;—I—43%RH
g 0'3000‘” *’ ‘11 I fl * ’ “f0 l 56%RH
‘E 0.2000 -- 11L W 7, W 75% RH
E, 0.1000 — r .. .. _. .. .. —W 1+34%RH
"é“: ‘si‘hé— +39%:

‘ ~‘ - —+—— 5

§-o.1ooo W |— R» ‘9'Q!'n_ 0 l +°
C

-0.2000 7

Time (hrs)

Figure 35. Net Change in thickness of GCF at 30°C at different humidity conditions
Width:

Significant change in width was observed at 89% and 95%. Material shrunk in the width
dimension (—0.60 inches and -0.50 inches) at these two RH% conditions. At 84 % RH,
material contracted in the width dimension slightly “ —0.132 inches”. At the remaining,
RH% conditions (11%, 43%, 56% and 75%), only slight (0.02- 0.04 inches) change was
observed. in width during the storage study period. Change in width can be seen in the

following graph.

90

 

 

 

 

 

 

 

 

 

 

Net Change in Width at 30C

0.2
.73: 0'1 flrfim —I 7* __ ¢_ ¢ _; I
E o 37...... =— . WWW—— +11%RH
§-0.1'WW W m Wu W--: W -m - 500 +43%RH‘
5-02. WWW W W WWW W - W 56%RH
'; -o_3 _ ‘ __ 1 W 75% RH
€044 ‘ ~ ~ ~ , '—x—-84%RH*
-= -o.5 - W '\§‘ ‘ W +89% RH
o
.6 _0_6. . M’ s ..- s, - +95%.RI1
z -o.7W W WW W ~

-0.8

Time(hrs)

Figure 36. Change in width of GCF at 30°C at different humidity conditions.

Length

Significant change was also observed in length at higher humidity conditions (95% and
89%). The material shrunk almost 0.90 inches in the length direction. At 84%RH material
contracted in the length direction only 0.23 inches. This behavior of the material can be
best seen in figure 6.

No significant change was observed at 1 1%, 43%, 56% and 75% RH.

91

 

Net Change in length at 30C

 

    

   

 

 

0.2000
A T
C
2. 0.0000 I 7 * +11%RH
'- 1 500 _
2’ 02000 W ”43% R“
2 56% RH
§ 04000 — 75% RH
g +84%RH
g '0-5000’ ‘—o—89%RH
‘5 -0.8000 W +9§%,RH
C

4.0000

 

 

1 Time(hrs)
Figure 37. Change in length of GCF at 30°C and different humidity conditions.

Figure (a)

 

50%RH and 25° C 95%RH and 30°C

 

92

Figure (b)

 

50% RH and 25°C 95% RH and 30°C

 

Figure No.38 (a and b): Comparison of GC F samples kept at 95% RH, 30°C and 50%RH
and 25°C. (Front View)

3.21 Material behavior at ambient conditions:

1” and 2” Green Cell foam was kept under observation in an air conditioned lab but not
controlled where temperature and relative humidity conditions changed according to the
weather conditions for about three months. Physically it was observed that material

increased in thickness. This behavior can be seen in the following figures 39 and 40.

93

 

Fresh GC F sample Three months Old GCF
(2- inch thickness) sample (2- inch
thickness)

 

Figure 39 (side view). Comparison of 2” fresh and three month old GCF material [5-a]

Fresh GCF sample Three months Old GCF
‘ (1- inch thickness) sample (l- inch thickness)

 

 

 

Figure 40. Comparison of l-inch fresh and three month old material

94

3.22 The Change in thickness of Green Cell® Foam under constant load at
controlled conditions (50% RH and 25° C)

The effect of load over time on the thickness of GCF was also determined. Both l-inch
and 2- inch foams decreased slightlyover time under load at 25 °C and 50%RH.

No significant change was observed during the storage period in thickness under load. A
weight of 4.3-4.5 kg weight was placed on the top of the foam pieces for 53 days. Only
0.0230 inches of net change in thickness was observed for 2-inch thickness material
during the storage period. While only 0.068 inches decrease in thickness was observed
for 1-inch thickness material. No physical, change was observed during the study period.

This behavior of material can be best seen in the following figures and tables

Table 8. Relationship between change in Thickness under load at 25°C and 50% RH

( 1- inch thick sample)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Time Thickness Thickness Thickness Average
days (i_n) (in) (in) thickness 5 dev
0 1.23 1.1965 1.2455 1.2240 0.03
1 1.205 1.1865 1.208 1.1998 0.01
2 1.209 1.208 1.223 1.2133 0.008
4 1.1885 1.1905 1.155 1.1780 0.02
6 1.188 1.176 1.145 1.1697 0.02
8 1.187 1.1725 1.144 1.1678 0.02
10 1.2245 1.1925 1.1715 1.1962 0.03
12 1.2035 1.174 1.1685 1.1820 0.02
15 1.2065 1.1955 1.1785 1.1935 0.01
17 1.171 1.1605 1.147 1.1595 0.01
19 1.202 1.1635 1.1645 1.1767 0.02
27 1.172 1.1495 1.164 1.1618 0.01
35 1.179 1.152 1.186 1.1723 0.02
48 1.1535 1.1385 1.1735 1.1552 0.02
Net change -0.0688

 

95

 

 

thickness under load

1.2600 .
1.2400
1.2200
1.2000
1.1800
1.1600
1.1400
1.1200

0 thickness

Thickness(ln)

R2 = 0.5239

 

0 10 20 30 40 50 60
Time(days)

 

Figure 41. Graph of Time (days) Vs Thickness of Green Cell® foam (1-ich thick GCF) at
25°C and 50%RH at constant load

Table 9. Relationship between change in Thickness under load at 25°C and 50% RH
(* 2-inch Green Cell® foam)

Time Thickness Thickness Thickness Average

2.2324 2.0695 2.

2. 06 1
2.2412 2.1255

2. 1

2.134

2.1

2.1605

2.

2.1335

1245

2.1
2.15
2.1125
2.1165

2.1215

 

96

 

2.30000

Thickness under load

 

2.25000

 

 

2.20000 ‘

 

2.15000 4

Thickness(in)

2. 1 0000

2.05000 —

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2.00000

0

20

4O
Time(days)

 

E 0 thickness

Figure 42. Graph between Time (days) Vs Thickness of Green Cell® foam
at 25°C and 50%RH at constant load(* 2-inch Green Cell® foam)

Combined results of 1-inch and 2-inch thick Green Cell® Foam can be seen in figure 43.

 

 

 

 

 

2.4000 ,
2.2000 W .T 3;: I4; -__ T__ ”T

1i {1- ’5 1E1 E i 1
2.0000 - WW- WW W. -.-._ . ,.
1.8000 ~— , *2_.
1.6000 WWWWW W k - 2- “if _

I 1.4000 «- W 1
1.2000 Wish ‘37- “i .32! 2W
1.0000
0 10 20 30 40 50

 

60

 

+—

E +

L,

1" thickness 1
axe.thickness '
2"
ave.thickness

l

 

1

1

 

Figure 43. Change in thickness under load at 25°C and 50%RH for 1 inch and 2-inch

GCF

97

3.23 Change in Thickness under load at ambient conditions:

Not significant change was observed during the storage period in thickness under load at
ambient conditions. This experimental set up was placed in air-conditioned room but not
controlled conditions (temperature and relative humidity conditioned varied). Total 5.9
kg weight was placed over the foam piece. Experiment was kept in progress for 23 days.
Inconsistence decrease and increase in thickness was observed during the
observation/study time. Only “-02.0 inches” of net change in thickness was observed for
2- inch thick GCF sample on the 24th day. While total 0.023 inches change in thickness
was observed on 24th day of storage study for the 2- inch thick GCF sample, which was
kept at controlled conditions (50% RH and 25°C).

Physically appearance of the foam was detoriated, material become soggy (because of
absorption of moisture from the environment) and slight change of shape was observed.

This behavior of material can be best seen in the following figure and tables.

Table 10. Relationship between change (A) in Thickness under ambient conditions.
(* 2-inch Green Cell® foam)

 

thickness(in)
2.135
2.181
2.13
2.137
2.071
2.048
2.129
2.067
2.042
1.945

Net change -0.19

 

 

 

 

 

 

 

 

 

 

a
N—k m
wuowmthWo<

 

 

 

 

 

98

 

Thickness vs time

N
to;_ro
AOIN

    
   

 

1'3
§ 0 Series1
c 2.05 ' 1‘
a :PdY- 13:06511‘
E 2 1
l-
1-95 R2=0.8211 ‘
l
1.9
0 5 10 15 20 25 1
l
l

Time(days)

Figure 44. Relationship between change Thickness under constant load at 25°C and
50% RH(* 2-inch Green Cell® foam)

99

3.3 Moisture Sorption
Moisture Sorption lsotherm.
Sorption isotherms of the biodegradable starch based foam (Green Cell®) were
determined at 20°C, 25°C and 30°C at several relative humidity conditions, by plotting
equilibrium moisture content of the product against water activity of the product
experimentally and the GAB model. In order to do this, it was necessary to determine the
foam moisture content. A Gravimetric method was used to determine foam moisture

content .
Sorption isotherm at different %RH and 20°C, 25°C and 30°C.

Since Green Cell® foam is biodegradable, it absorbs moisture, which affects its packaging
performance properties. Moisture sorption isotherms at three temperatures were
developed to determine the moisture sensitivity of the product.

Gesamtverband der Deutschen versicherungswirtschaft e.v defines the term hygroscopity
as the “capacity of a product to react to the moisture content of the air by absorbing or
releasing water vapor. Of decisive significance for the absorption or release of water

vapor is the water of a product”[27].

Further the sorption isotherm is defined, as “A sorption isotherm is the graphic
representation of the sorption behavior of a substance. It represents the relationship
between the water content of a product and the relative humidity of the ambient air

(equilibrium) at a particular temperature”.

100

Sorption behavior of a hygroscopic product is related to its ability to absorb or release
water vapor from air (or into the air) until equilibrium is reached.

Sorption isotherms were plotted to determine the moisture sensitivity of the Green Cell®
Foam. Initial moisture content (Mi) of the foam was determined to be 1.26%. Moisture
sorption isotherms were determined at three different temperatures 20°C; 25°Cand 30°C.
The GAB model was then used to obtain the best fit of the data. Quadratic regression
analysis was performed by plotting aw/Me vs Me to obtain various model constants.

The material was much more hygroscopic at higher temperatures as compared to lower
temperature. Green Cell® foam was shown to have a hygroscopic nature. The sorption
isotherm profile is a characteristic of the hygroscopic nature of a product. The sorption
behavior of a product is dependent on temperature. Highly hygroscopic products exhibit a
steep sorption isotherm, while sparingly hygroscopic products exhibit flat sorption
isotherms [27]. The hygroscopic nature of a product can be judged by the magnitude of
the increase or decrease of a product’s water content as a function of relative humidity or
water activity at a certain temperature. Weakly hygroscopic products exhibit no or only a
slight change in their water content as a consequence of variations in relative humidity. In
strongly hygroscopic products, water content may vary widely [27], which was found to

be the case for Green Cell® foam.

Types of Sorption isotherm:
Generally in the literature three types of sorption isotherm are considered.
1) Sorption isotherm in which the product shows strong hygroscopic nature. As
shown‘in Figure 45,this product exhibits a steep rise in product moisture content

as a function of %RH.

101

 

 

 

WCZ

EST

30""

 

25 «.-
20 ~r-
lS--

10 *1-

o 1?: sin 2&3 42) sin ti: 'fio an: 9E) idmr""""l

 

 

#1—

 

Figure 45. Plot between the moisture content (%) and relative humidity RH (%)

2) Sorption isotherm, in which the product exhibits an S-shaped profile, as, shown in
Figure 46

 

 

 

Water cnntent Z
35--

 

301*

25 ...-

10'“

5+-

 

 

 

 

: n
T Y

:::: 1' WW'
010203040506008090100

Figure 46. Plot between the moisture content (%) and relative humidity RH (%)

102

The flat linear portion of this graph represents the most stable form of the product. Above
and below this region, harmful changes may occur in the product. [27]

3) Anhydrous product generally exhibits 10w hyrosocopicity, however, once the flow
moisture point has been reached, the product rapidly absorbs large amounts of water
vapor, its exhibits a deliquesce (hydrous form), as shown in figure 47. Many crystalline
products (salt, sugar, potash, tartaric acid) exhibit this behavior. [27]. Equilibrium

sorption isotherm provides information about the hydroscopic nature of material. [19]

 

Water content %

 

 

 

SS-F
130-1-
25 --
20-1-
15 w-
10 -‘-

5.1-

0 1'0 2'0 3'0 4'0 5'0 6'0 7'0 8'0 9'0 1 00L

 

 

4A A

 

Figure 47. Plot between the moisture content (%) and relative humidity RH (%)

Sorption behavior of Green Cell® Foam was found to more closely resemble with type
two at 20°C, 25°Cand 30°C as shown Figure No. 48. 49 and 50.

Sorption isotherm was determined using a liner method and graphical representation is

shown in the following figures 48-50.

103

 

 

0.4

0.35 11- —

.0
w
1

0.25 ~» ,

0.15 ~

1

.0
o
01
1
T

 

Equlibrlum water content(Me)(g)
O
N
1

 

O

y = 0.2749x + 0.0208
0 - _- ~ 1 * *- R2 = 0.8549

 

'+ Me
]—_Linear (Me)

 

 

 

0.00

Figure 48.

0.20 0.40 0.60 0.80 1.00
water activity(Aw)

Sorption isotherm of GCF at 20°C

 

 

 

Equilibrium moisture
content(Me)(g)

y = 0.3545x - 0.0117
R2 = 0.811

 

1+ Me
.—_ WMLifnear (Me)

 

 

 

 

 

 

Water activity(Aw)

Figure 49. Sorption isotherm of GCF at 30°C

104

 

0.3

 

0.25 -
y = 0.2422x - 0.0011
0.2 . R2 = 0.8918
1] A Lilear (Me)

 

0.1 1

 

0.05

 

 

Equilbrium moisture content(Me)(g)

 

 

 

 

Water activity

Figure 50. Sorption isotherm of GCF at 25°C

Since the product did not follow a linear relationship between the aW and Me, the GAB

model was selected to represent the sorption isotherm.
GAB (01, B, Y) constants were taken from slope of the line for aw/Me vs. aw and

calculating T, C, Wm and K to get the calculated GAB value. T, C, Wm and K (GAB
constants) were calculated using the following formula. Detailed calculations can be seen

in appendix-C, moisture sensitivity of Green Cell® Foam.

T

fij+4
-ory

C

r :l: r T2 — 4T)"2

2
w...= 1/13 [ 1- 2/C]

K = 1/7 *1/Cw...

105

Calculation of Me (cal) can be achieved using the following expression
M = CkAw

Wm (l-kAw) (l-kAw+CkAw)

Substituting the values into the above equation and solving for Mme, gives a value of
Me (cal) at different water activities.

The RMS values are calculated using the following formula.

 

RMS = \1[2{(Mexp _ Mcal)/Mexp}2 /N] * 100

Sorption isotherm by GAB Model:
GAB model (01, B, y) constants were taken from the slope of the following Graph(figure

51) in order to get the calculated Me (GAB) values at 20°C

 

) _y =;1_1_.1o1x’_+ 13.55:: - 0.1467 __
R2 :- 0.9892

 

 

 
   
 

 

 

awlllo
N
1

 

 

{14 05 DEL (17 QB 09

Water activ lty(aw)

Figure 51. Plot of aw/Me and water activity at 20°C

106

Comparison of GAB model (calculated values) and experimental values of Me are
shown. Detailed calculations are shown in appendix-C, Moisture sensitivity of Green
Cell® Foam.

The RMS value was calculated to be 5.00.

 

   
 

 

 

 

 

 

 

0.3
8 0.25W W n, f ,- -0
"6
2
g 0.2 - _
8
:9} 0.15W- - ,,
C
s
S
o 0'1 i 0 Experimental ‘ T
g —I—GAB ‘
I» 0.05 W30. - 2--
O
E
o .
o 02 0.4 06 08 1
aw

Figure 52. Comparison of Moisture sorption isotherm for Green Cell Foam based on
experimental data and GAB model at 20°C [5-a].

To plot the sorption isotherm using the CAB model at 25° C
GAB model (01, B, y) constants were taken from the slope of the following Graph

(figure 53) to get the calculated Me values.

107

Plot of Aw/M Vs Aw

 

 

 

 

 

 

 

6
o
5 __ fl _ ._ .
o
4 1 _ _ WWW W W W _
E31 -- *4 WWW—WW - ----~y=-1L635x’W*18.702x¢0.1599. -0- 4-.-
g a
(21* W -___ -_0Rz'°9‘£’ H _ n - _
11W W _ WWW W -W ,____ _ _ .W W. W
0 . . . .
_1 (L 0.1 0.2 0.3 0.4 - 0.5 0.6 0.7 0.8 09

 

AW

Figure 53. Graph between aw/Me and water activity at 20°C

The GAB isotherm and experimental values at 25°C is presented in figure 54.

 

 

 

 

 

 

“6
9 0.3
O
N 0.25«» W- - — _ - . m
E O Experimntal .
g“ 0.2 ..__ ___ .- -_ m
E 3!
0‘ 0.15 W-W- W W-
a 8
0
0 0.1 W- WW __ _m
2 M
:3 0.05/ ‘ ~ W 40A-
0
2 o .
0 0.2 0.4 0.6 0.8 1

Aw

Figure 54. Moisture sorption isotherm of Green Cell® foam at 25°C.

108

Detailed calculations are presented in appendix-C, Moisture sensitivity of Green Cell®
Foam.

The RMS value was found to be 8.53 [5-a].

To plot the sorption isotherm at 30 C using the CAB model
GAB model (OK, 8, y) constants were taken from the slope of the Graph (figure 55) to

get the calculated Me values using the GAB model.

Plot of Aw/M Vs Aw

 

      

v = 412295? + 153543! 99123
R2 . 0.9805

AwIM

 

 

 

43.5 0.1 Q.Z___Q.3___0.4 M 0.1 (LL—.93 1.9
Aw

 

Figure 55. Plot of aw/Me and water activity at 30°C

Comparison of the GAB predicted isotherm and the experimental isotherm is shown in

figure 56.

109

0.45

 

0.35W , , - o —-

 

 

Moisture Content(gofH20/g of solid)

 

 

 

Figure 56. Comparison of the moisture sorption isotherm (GAB and experimental) of
Green Cell® Foam at 30°C [5-a].

Detailed calculations can be seen in appendix-C, Moisture sensitivity of Green Cell®

Foam.

RMS value was found to be 8.6847. [5-a]

Moisture loss or gain
Moisture absorbing/desorbing behavior under different humidity conditions at 20° C,25°C

and 30°C is shown in the figures 57 and 59.

110

Moisture gain/loss behavior at 20°C followed the same pattern as GCF at 25°C and 30°C

but at a slower rate. Fungus was observed on the GCF at 96%RH afier 35 days of storage.

 

Figure 57. Fungus on GCF at 20 C and 96% RH

Most significant weight changes were obserevd at 75%, 84% and 96%. At 75%and 84%
RH, material expanded during the first week of storage and gained moisture. At higher
humidity conditions like 96% RH, material lost its shape and contracted during the first
few days of storage but gained moisture. After the first week of storage, the material
again started to expand but never regained its shape. After one month of storage, it was
observed that mold was growing on the material which was kept at 96% RH.

At 25°C the most significant change can be seen at 75% and 84% .At 75%RH, material
expanded during the first week of storage study and gained moisture. No significant

physical change was observed at 51%, 35% and 23% RH.

111

At 75% and 84% material gained moisture and also expand. This behavior is shown in

the following Figures 58 and 59.

   

 

Sample kept at RH75°/o Fresh sample
And 30 C

Figure 58. Comparison of fresh sample and material kept at RH75% and 30°C

 

 

 

2% A5 /.
Th“. On kink
So MM

“P“ 6‘4“...

   

 

l
Fresh sample Sample kept at 95% RH
and 30C

 

 

 

Figure 59. Comparison of fresh sample and material kept at RH 95% and 30°C

112

At higher Relative humidity conditions (89% and 95%) material lost its shape, contracted
but gained moisture. Retrogradation may affect Green Cell® foam at higher humidity
conditions and may be why it lost its shape and became brittle. At 43% and 54% no
significant change was observed during the storage.

The material absorbed moisture at 75%, 84%, 89% and 95% RH at 30°C. At 95% RH, the
material absorbed the maximum quantity of moisture as compared to 89% RH, 84%RH
and 75% RH. At 95% RH, material absorbed 0.844 grams of moisture during 408 hrs of
storage [S—a]. At 89%, material absorbed 0.74 grams, at 84% RH 0.32 grams and at 75%
RH 0.177grams.At 11% RH the material lost moisture (-0.10 grams).

At higher Relative Humidity conditions (89% and 95%) material shrunk but gained
moisture. At 43% and 54% no significant changes were observed At 56% RH the
material absorbed only 0.0001 grams of moisture and thus it is concluded the ideal
relative humidity conditions for Green C ell® Foam.

This behavior is shown in the following graph [5-a].

113

 

Net weight change at 3°C

 

:35 +11% RH ‘
2’ +43% RH .
2 56%RH K
3:3 75%RH 1“
3,2: +84% RH 1
3 _ . a _ +89%RH ‘
g .1 4. 0;} W “1;, gen“.- £4" 5".) .4 . m. :QEflRl-Ll

...J‘IEQV “v.3 WWW “w

{wwmwfl‘xdh l

 

Time(hrs)

Figure 60. Net Change in weight at 30°C and different humidity conditions.

At 11%, 43% and 54%, no significant changes were observed. Detailed calculations can
be seen in appendix B— dimensional changes. The most ideal conditions for the material is
at 30°C was 56% RH .L, x W, x T change (—0.01 x —0.01 x0.075) inches) respectively.
Ideal conditions for Green Cell® Foam is 56% relative humidity. Net moisture gain at
55% RH and 20°C was only 0.01 grams after 35 days of storage, while at 25°C and 51%
RH, net moisture gain was only 0.0008 grams after 15 days of storage. This leads to the
conclusion that the ideal storage condition for this material is 50-56% RH at 25°C.

The product showed the same pattern of absorbing/desorbing behavior under the different

temperature conditions of 20° C, 25°C and 30°C as this pattern.

114

3.4 Thermal insulation

Package insulating ability (R Value) and bulk density of Green Cell foam.

The insulating ability of Green Cell® foam and EPS coolers was determined at two
different conditions (25°C, 50% RH and 30°C, 80%RH). Bulk density of one inch thick
and two-inch thick Green Cell® foam was calculated.

Bulk density

Bulk density is defined as the weight per "unit volume of the material [9] .For one-inch
thick foam was found to be 3.071bs/ft3and two inch thick foams was found to be
3.35711bs/fi3 [5-a]. Density values were calculated from triplicate measurements and
detailed calculations can be seen in appendix D, R-value and density calculations.
Traditionally, expanded polystyrene (EPS) has been the sole foam packaging material
used for coolers.

The bulk density of Green Cell® foam, is much higher than expanded polystyrene foam
and other commercial foams. Total weight of the package would increase substantially
because of the higher density of the GCF. Bulk densities range from 1.25 pcf to
2.2pcf,density for EPS, PE, ARC EL512, and polyurethane.

R—value:

“The R-value Rule has been helpful in comparing different brands of the same type of
insulating materials” said Betsy de Campos, executive director of EPSMA, “ but as more
sophisticated materials and higher technology construction systems are introduced into
the building industry we find that R- value of the material does not tell the whole

story.”[23]

115

The R- value is based on the mathematical term known as the R- factor. The term R-
value was developed to represent the ability of an insulation material to restrict flow.
Thermal resistance of a material is its resistance to heat flow and is expressed as the
reciprocal of the material’s thermal conductivity. Simply put, the greater the R-Value the
better the insulation. [23]

Traditionally, expanded polystyrene (EPS) was the sole foam packaging material [12].
Polystyrene foams are considered to have excellent balance between cost and
performance for the insulation and packaging fields. Polystyrene also has superior shock
absorbing properties. [13] This, therefore; was the basic reason to compare the R- value
of Green Cell® coolers with EPS coolers.

EPS and Green Cell® coolers were made to have the same dimensions. Identical buckets
(same size and same color) were used in the EPS and Green Cell® coolers. To compare
the R— value of Green Cell® cooler with the EPS coolers, experiments were performed at
the same time, in the same environments with the same equipment and the same amount
of ice. The conditions used a) 50%RH and 25°C b) 30°C and 80% RH

It was found that the EPS cooler had a 10% higher R- value than GC at 50% RH and
25°C and at the higher temperature and relative humidity the EPS cooler had 20% higher
R —value as compared to Green Cell® cooler. This indicates that Green Cell® degraded
with increase in humidity. It absorbed moisture, which increased its thermal conductivity
and thus lowered it’s R- value.

Thermal conductivity of cellular plastic is directly affected by factors like density, cell
size, polymer composition and gas phase. [12] Thermal conductivity of cellular plastic

and elastomers is defined by the K factor, which is defined by Fourier’s equation for

116

conduction through homogeneous materials. Total K factor (MC Intire and Keddedy,
1948) is separated into components of different modes of heat transfer .As shown in the

following equation.

K= ks+kg+kr+kc

Where

k5 = conduction through solid
kg = conduction through gas
kr = radiation

kc = convection in the gas

These factors can affect the R-value of cellular plastic foams.

As density increases, kr (thermal conductivity due to radiation) decreases but in this case
no mode of radiation and convection existed only conduction was available, which is
responsible for the R- value. The overall change in k usually decreases with increase in
density to a minimum at 2pcf(lbs per cubic feet) [12] and then increases with increasing

density of the foam above 2 pcf. Since the R- value is the reciprocal of K factor [12], thus
Green Cell® will have a lower R— value than the EPS cooler because of its higher density.
(3.3pct).

At higher relative humidity conditions Green Cell® shows a greater discrepancy than EPS
(about 20%) as the material has a more hygroscopic nature as compared to EPS and picks

up moisture at a faster rate.

117

At higher humidity conditions, the carbohydrates in Green Cell® foam can absorb more
moisture than EPS, thus causing a decrease in the R-value. Green Cell® polymer
composition and cell size at different humidity conditions effect R-values.

It is difficult to extrapolate, based on these studies, R-values of Green Cell® foam at
other temperatures, because of the direct effect of relative humidity. R-value is not linear

with temperature and RH increase.

Table 11. R-values of EPS cooler and Green Cell cooler at different conditions [5-a].

 

 

 

 

 

 

 

 

 

 

 

 

 

Temp. RH Time EPS Green Cell® R-Value
°F % hr Unit
77 50 24 14.2019 13.24 fi2*h.r*°F/BTU
77 50 48 12.8250 11.918 fi2*hr*°F/BTU
86 80 26 10.0455 7.803 ft2*hr*°F/BTU

 

* Dimensions of EPS cooler and Green Cell cooler: l 1W l6"‘10”8*9” 8

118

CHAPTER 4

CON SLUSION S

Biodegradable packaging materials will find niche markets as long as their properties are
comparable to currently used synthetics.

Dimensional stability is an important parameter for plastic foams. It represents the
ability of a material to retain its original shape and size in varying environmental
conditions. Since GCF is a hygroscopic material it was not able to retain its dimensions at
high RH and temperature conditions. Cushioning characteristics of Green Cell® Foam
are also affected by high temperature, high RH and long storage time. Green Cell® Foam
can be used for those products such as electronics which are not moisture sensitive and
have fragility level 30-45 G. One-inch foam can be used for rugged appliances when
these items are shipped and stored in controlled environments for a short period of time.

Thermal insulation properties of Green Cell® Foam showed comparable results

with EPS at standard RH and temperature (25 °C, 50% RH) conditions. Green Cell®

coolers could be an effective package for pharmaceuticals when these items are shipped
and stored in controlled environments for short periods of time.

Green Cell® Foam is a hygroscopic material whose properties change
substantially at high RH. For high RH applications, and for the packaging of produce
and other perishables, this will need to be addressed to create more opportunities for its

use as packaging foam.

119

4.2 RECOMMENDATIONS

Polymer composition and cell size of Green Cell® at different humidity conditions
should be investigated and affect of these factor upon R-values are those points which are

recommended for further study.

Molecular structure of Green Cell® Foam would be studied in depth to investigate its

hydroscopic nature.

120

APPENDIX A

CUSHIONING CHARACTERISTICS

' Tables G 1 to G 7 represent the information about the shock characteristics of
Green Cell® foam having thickness of 1 inch.
Table G1. Shock characteristics

Shock characteristics 1" thickness

Weight = 12.8|bs
Area=64in2

Static pressure=0.2 psi
Gate time=3.67

 

 

 

 

 

 

 

 

Height =24in
Filter = 156
s.no G value time Velocity
1 56.76 17 187.06
2 55.56 17.2 187.6
3 56.29 16.9 186.07
4 57.41 17.5 196.37
5 57.09 17.7 193.69
Ave. 56.622 17.26 190.158
s.dev 0.7241 0.3362 4.5803

 

 

 

 

 

 

 

Table G2. Shock characteristics

Shock characteristics 1" thickness

Weight = 12.8|bs
Aear=36in2

Static pressure=0.355 psi
Gate time=3.67

 

 

 

 

 

 

 

 

Height =24in
Filter = 156
s.no G value time Velocity
1 59.39 17.3 195.45
2 64.92 16.1 197.76
3 61.28 16.4 196.31
4 65.04 15.8 198.03
5 64.29 15.9 195.96
Ave. 62.984 16.3 195.02
s.dev 2.5249 0.6042 1.1352

 

 

 

 

 

 

121

Table G 3. Shock characteristics

Shock characteristics 1" thickness

Weight = 51lbs
Aear=64in2

Static pressure=0.8 psi
Gate time=3.67

 

 

 

 

 

 

 

 

Height =24in

Filter = 156
.no G value time Velocity
1 79.6 12.9 196.35
2 78.12 12.9 193.67
3 80.93 12.6 194.22
4 84.26 12 193.37
5 81.11 12.4 193.69
Ave. 80.804 12.56 195.02
s.dev 2.2752 0.3782 1 .2078

 

 

 

 

 

 

Table G4. Shock characteristics

Shock characteristics 1" thickness

Weight =

47|bs

Aear=36in2
Static pressure=1.305 psi
Gate time=3.67

 

 

Height =24in

Filter =156
s.no Gvalue time VelocitLl
1 117 10.3 226.42I

 

 

 

 

 

122

Table G5. Shock characteristics

Shock characteristics 1" thickness

 

Weight = 52|bs

Aear=36in2

Static pressure=1.44
Gate time=3.67

Height =24in

Filter = 156

6 value

122.1
107.
117.3

115.806
7

Table G 6. Shock characteristics

Shock characteristics 1" thickness

Weight = 57|bs
Aear=36in2

Static pressure=1.58
Gate time=3.67

 

 

 

 

 

 

 

 

 

 

 

 

Height =24in
Filter = 156
s.no G value time Velocity
1 114.18 10.6 219.51
2 124.69 9.6 223.1
3 112.62 10.4 219.62
Ave. 117.1633 10.2 220.7433
s.dev 6.5648 0.5292 2.0417

 

123

 

Table G7.Shock characteristics

Shock characteristics 1" thickness

Weight = 62|bs
Aear=36in2

Static pressure=1.722
Gate time=3.67

 

 

 

 

Height =24in
Filter = 156
s.no G value time Velocity
1 131.47 9.6 229.4
2 130.92 9.3 228.96
3 130.23 9.5 226.49

 

 

 

Ave. 130.8733 9.4667 228.2833

 

 

 

 

s.dev 0.6213 0.1528 1.5686

 

 

 

124

' Tables G 8 to G16 represent the information about the shock characteristics of

Green Cell® foam having thickness of 2- inch.

Table G8. Shock characteristics

Shock characteristics 2" thickness

Weight =12.8lbs

Area =36in2
Static pressure = 0.355 psi

Gate time =3.67

Height = 24in

 

 

 

 

 

 

 

 

 

 

 

Filter = 156

s.no G value time Velocity

l 39.97 22.8 177.25

2 38.58 23 170.57

4 39.22 22.9 172.57

6 39.15 22.1 169.92

7 38.42 22.8 169.86
ave. 39.0680 22.7200 172.0340

st dev. 0.6127 0.3564 3.1158

 

 

125

 

Table G 9. Shock characteristics
Shock characteristics 2" thickness

Weight = 37lbs

Area = 64in2

Static pressure = 0.578
Gate time = 3.67
Height = 24in

 

 

 

 

 

 

Filter = 156
s.no G value time Velocity
1 34.61 21.5 164.56
2 38.3 20.7 166.49
3 37.99 20.5 167.81
4 34.1 21.8 165.1
5 31.96 21.9 162.47

 

Ave. 35.392 21.28 165.286

 

 

 

 

 

s.dev 2.7049

 

 

Table G 10. Shock characteristics

Shock characteristics 2" thickness

Weight = 421bs
Aear=64in2

Static pressure=0.65625
Gate time=3.67

Height =24in

 

 

Filter = 156
s o Gvalue time Velocity
34.65 22.5 169.45

 

31.75 22.9 165.88

 

31.16 22.9 166.67

 

34.59 22 170.05

 

Mauro—M:

31.79 22.9 165.86

 

Ave. 32.788 22.64 167.582

 

 

 

 

 

s.dev 1.6910

 

 

126

 

 

Table G11. Shock characteristics

Shock characteristics 2" thickness
Weight = 51.001bs
Aear=64in2
Static pressure=0.8125
Gate time=3.67
Height =24in

 

 

 

 

 

 

 

 

Filter = 156
s.no G value time Velocity
l 37.14 21.1 168.34
2 38.23 23 168.26
3 34.54 21.6 175.91
4 29.56 25.7 161.83
Ave. 34.8675 22.85 168.585
s.dev 3.8621

 

 

 

 

 

 

Table G12. Shock characteristics
Shock characteristics 2" thickness

Weight = 521bs
Aear=36in2

Static pressure=1.444 psi
Gate time=3.67

Height =24in

 

 

 

 

 

 

 

 

Filter = 156
s.no G value time Velocity
1 40.03 23.9 174.2
2 40.96 21.8 171.93
3 40.01 21.7 170.31
4 48.65 20.6 189.95
5 40.31 21.8 167.7
Ave. 41.992 21.96 174.818
s.dev 3.7417 1.1971 8.7848

 

 

 

 

 

 

127

Table G 13. Shock characteristics

Shock characteristics 2" thickness

Weight = 57le
Aear=36in2

Static pressure=1.583 psi
Gate time=3.67

Height =24in

 

 

 

 

 

 

 

 

Filter = 156
s.no G value time Velocity
1 36.97 21 158.4
2 36.63 22.3 162.21
3 31.55 22.6 143.42
4 31.7 22.8 142.45
5 31.31 24.1 148.79
Ave. 33.632 22.56 151.054
s.dev 2.8978 1.1104 8.8861

 

 

 

 

 

 

Table G 14. Shock characteristics
Shock characteristics 2" thickness

Weight = 621bs
Aear=36in2

Static pressure=1.722 psi
Gate time=3.67

Height =24in

Filter = 156

 

o G value time Velocity

 

39.57 21.5 164.46

 

43.13 22.3 178.81

 

39.75 20.8 163.49

 

hWNu—Ib

41.15 21.4 174.37

 

 

Ave. 40.9 21.5 170.2825

 

s.dev 1.6459 0.6164 7.5159

 

 

 

 

 

 

128

Table G 15. Shock characteristics

Shock characteristics 2" thickness

Weight = 63.3le
Area=36in2

Static pressure=1.758 psi

Gate time=3.67
Height =24in

 

 

 

Filter = 156
s.no G value time Velocity
1 37.52 21.8 161.13

 

 

 

 

Table G16. Shock characteristics

Shock characteristics 2" thickness

Weight = 12.8|bs

Aear=36in2

Static pressure=0.355

Gate time=3.67
Height =24in
Filter = 156

129

 

. Table G17 represents the shock characteristic information before storing at
different humidity conditions and 30°C and table G 18 represents shock

characteristic information after the storage study at different humidity conditions
and 30°C.

Table G17. Shock characteristic information before storing at different humidity

conditions and 30°C.

 

 

 

 

 

 

 

 

 

 

 

Date: 10/21/2003
s.no G value time Velocity Wt. of sample
G's ms in/sec g
1 39.97 22.8 177.25 51.62
2 38.58 23 170.57 52.65
3 32.18 25.2 158.19 54.58
4 39.22 22.9 172.57 51.86
5 32.9 25.8 164.47 56.34
6 39.15 22.1 169.92 51.51
38.42 22.8 169.86 52.38
Ave. 37.203 23.51429 168.976
s.dev 3.2311 1.3981 6.0859

 

 

 

 

 

 

 

Table G18. Shock characteristic information after the storage study at different humidity

conditions and 30°C.

 

 

 

 

 

 

 

 

 

 

s.no RH % G value time velocity wt. Of sample
% G's ms in/sec g
1 11 51.84 17 182.63 58.68
2 43 45.21 18.1 174.4 52.64
3 54 38.29 21 171.59 54.7
4 75 36.53 22.6 169.08 53.96
5 86 37.25 18.8 153.64 62.03
6 89 50.63 16.4 163.43 60.59
7 97 76.77 12.4 184.1 67.31

 

 

 

 

 

 

130

 

I Table G19 (a, b and c). Shows the comparison of shock characteristics of Green
Cell® foam before the storage study and after the storage study at different
relative humidity (%RH) conditions and 30°C.(Table G19-a)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Table G19 (a)
10/21/03 12/23/03 10/21/03 12/23/03 Aw
s.no RH G value G value wt. wt. net wt. gain
% (8) (8) (g)
1 11 39.97 51.84 51.62 52.68 1.06
2 43 38.58 45.21 52.65 52.64 -0.01
3 54 32.18 38.29 54.58 54.7 0.12
4 75 39.22 36.53 51.86 53.96 2.1
5 86 32.9 37.25 56.34 62.03 5.69
6 89 39.15 50.63 51.51 60.59 9.08
7 97 38.42 76.77 52.38 67.31 14.93
(Table G19-b)
Date 10/21/2003 12/23/2003 10/21/2003 12/23/2003
s.no RH time time velocity velocity
% (ms) (ms) (in/sec) (in/sec)
1 11 22.8 17 177.25 182.63
2 43 23 18.1 170.57 174.4
3 54 25.2 21 158.19 171.59
4 75 22.9 22.6 172.57 169.08
5 86 25.8 18.8 164.47 153.64
6 89 22.1 16.4 169.92 163.43
7 97 22.8 12.4 169.86 184.1
Table G19. Comparison of G values of Green Cell® foam at different relative humidities
and time (days)
Table 19-c)
Time RHl 1 1% RH 45% RH 56% RH 77% RH 8400% RH90% RH 96%|
10/21/03 39.97 38.58 32.18 39.22 32.9 39.15 38.42 I
12/23/003 51.84 45.21 38.29 36.53 37.25 50.63 76.77 I

 

 

 

 

 

 

 

 

 

131

 

 

 

 

 

 

 

 

time (days)

Graph between G values and time

90 .
80 ~ —, 1 o RH11°/o ‘
a 70 ’ J I RH 45% 5
£3 60 ” ‘ 7 '7 ‘ RH 56% l
3 50 h . ’1 1 RH 77°/ 1?
7:; 40 7 ’9 x ’ l 00 ll
> 30 1, x f , .. :1: RH 8400/...g
(D 20 WW -W -_ W - W W W WWWWWWW .W W WWWW .4 O RH90% ‘
10 W W + RH 96% l

0 .
10/6/200 10/26/20 11/15/20 12/5/200 12/25/20 1/14/200 1
3 03 03 3 O3 4

 

Figure G1. Graph between G value and Time (days)

Table G 20. Comparison of G values of Green Cell® foam at different relative humidities
with respect to time

 

 

 

 

 

 

 

 

lRH % 10/21/2003 12/23/2003
1 1 39.97 51 .84
45 38.58 45.21
56 32.18 38.29
77 39.22 36.53
84 32.9 37.25
90 39.15 50.63
96 38.42 76.77

 

 

 

 

 

132

 

copmarison of G values

70710/2—172-063
. 12/23/2003.

G values

 

Relative Humidity(RH°/n)

 

Figure G 2. Graph between G values and Relative Humidity conditions (RH%)

Shock characteristics and time effect

Table G 21. Shock characteristics of Green Cell® foam

Shock characteristics 2" thickness
Weight = 51.001bs
Aear=64in2
Static pressure=0.8125
Gate time=3.67
Height =24in
Filter = 156

G value
37. 4

34.54
29.56

 

133

 

Table G 22. Shock characteristics of Green cell foam

Shock characteristics 2" thickness
Weight = 51.001bs
Aear=64in2
Static pressure=0.8125
Gate time=3.67
Height =24in
Filter = 156

Time : Sept.19,2003

 

s.no Gvalue time Velocity Condition

 

l 22.05 30.1 130.95 Platen donot bounces back

 

2 24.28 28.2 130.67 Platen donot bounces back

 

24.28 28.5 134.34 Platen donot bounces back

 

24.88 27.6 133.59 Platen donot bounces back

 

(II-bu)

25.6 27 137.1 Platen donot bounces back

 

Ave. 24.218 28.28 133.33 Platendonotbouncesback

 

 

 

 

 

 

s.dev 1.3282 laten donot bounces back

 

 

Table G 23. Shock characteristics of Green cell foam

Time oct. 21,2003

2nd set of material fresh samples

Weight = 51.001bs
Aear=64in2

Static pressure=0.8125
Gate time=3.67
Height =24in

 

 

 

 

 

 

 

 

 

 

 

 

 

Filter = 156
s.no G value time Velocity
ms in/sec

1 34.28 21.1 166.34

2 37.32 23.2 168.34

3 34.54 21.6 173.91

4 37.14 24.7 161.83

5 35.38 23.02 169.29

' Ave. 36.095 22.724 167.942
s.dev 1.3567 1.424739 4.4021438

 

 

134

Table G24. Shock characteristics of Green cell foam

Shock characteristics 1" thickness

Weight = 511bs
Aear=64in2
Static pressure=0.8 psi
Gate time=3.67
Height =24in
Filter = 156
Time : July 15, 2003

 

 

 

 

 

 

 

 

 

 

 

 

s.no G value time(ms) Velocity(in/sec)

1 79.6 12.9 196.35

2 78.12 12.9 193.67

3 80.93 12.6 194.22

4 84.26 12 193.37

5 81.11 12.4 193.69
Ave. 80.804 12.56 195.02
s.dev 2.2752 0.3782 1.2078

 

Table G 25. Shock characteristics of Green cell foam

Shock characteristics 1" thickness

Weight = 511bs
Aear=64in2
Static pressure=0.8 psi
Gate time=3.67
Height =24in
Filter = 156
Time : Sept 19,2003

 

 

 

 

 

 

 

 

 

 

s.no G value time(ms) Velocity(in/sec)

1 55.84 14.8 173.52

2 51.41 15.7 166.83

3 47.59 16.6 167.4

4 51.89 15.2 165.76
Ave 51.683 15.575 168.3775
s.dev 3.3740 0.7762 3.4951

 

 

 

135

 

Another attempt
Weight = 511bs
Aear=64in2

Static pressure=0.8 psi

Gate time=3.67
Height =24in

Table G26. Shock characteristics of Green cell foam

 

 

 

 

 

 

 

Filter = 156 Time sept.20,2003
s.no G value time(ms) Velocity(in/sec)
l 48.24 16.6 163.12
2 51.39 15.6 167.73
3 52.08 15.2 168.48
4 49.65 16.5 168.78
Ave. 50.34 15.975 167.0275
s.dev 1.7336 0.6850 2.6422

 

 

 

 

 

 

 

Table G27. Shock characteristics of Green cell foam

Shock characteristics 1" thickness

Weight = 511bs
Aear=64in2
Static pressure=0.8 psi
Gate time=3.67
Height =24in

 

 

 

 

 

 

 

 

Filter = 156
Oct.2l,2003
s.no G value time Velocity
1 79.6 12.9 196.35
2 78.12 12.9 193.67
3 80.93 12.6 194.22
4 84.26 12 193.37
5 81.11 12.4 193.69
Ave. 80.804 12.56 195.02
s.dev 2.2752 0.3782 1.2078

 

 

 

 

 

136

 

 

Figure G 3. Comparison of Green Cell® foam material kept at 50% RH ,25°C and 11%
RH ,30°C.(Front view)

Material kept at 1 Material kept at 30C
25C and 50%RH and 11% R11
1

 

Figure G 4. Comparison of Green Cell® foam material kept at 50% RH, 25°C and 1 1%
RH, 30°C.(Side view)

137

 

Figure G 5. Comparison of Green Cell® foam material kept at 50% RH , 25°C and 43%
RH ,30°C.(Front view)

Material kept at Material kept at
25C and 50% RH 30C and 43% RH

 

Figure G6. Comparison of Green Cell foam material kept at 50% RH, 25C and 43% RH
,30C.(Side view)

138

Material kept at Material kept at
25C and 50% RH 30C and 43%

 

 

Figure G 7. Comparison of Green Cell foam material kept at 50% RH, 25C and 43% RH
,30C.(Front view)

Material kept at Material kept at 30C
25C and 50% RH and 54% RH

 

 

Figure G 8. Comparison of Green Cell foam material kept at 50% RH, 25C and 43% RH,
30C.(Side view)

139

APPENDIX B

DIMENSIONAL CHANGES AND MOISTURE GAIN/LOSS

Dimensional Changes and Moisture gain/loss with respect to time at 11% RH and

30°C.

Table D 1. Dimensional change data of sample no. “1”

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

S.No.1

Date Time Length Width Thickness Weight
hrs (L) in (W) in (T) in (wt) g

10/22/2003 0 2.1105 2.019 1.1785 4.1529
10/23/2003 24 2.077 2.0045 1.166 4.016
10/24/2003 48 2.1075 1.978 1.1585 4.0182
25-Oct 72 2.109 2.013 1.1785 4.0091
10/27/2003 96 2.0915 2.03 1.1935 4.0378
10/28/2003 120 2.099 2.016 1.19 4.0094
10/29/2003 144 2.122 2.014 1.197 4.0195
11/31/2003 192 2.1025 1.994 1.187 4.0605
1 1/2/2003 240 2.107 2.005 1.2095 4.0715

11/5/2003 312 2.0755 1.996 1.2 4.08
11/7/2003 360 2.083 2.007 1.207 4.0728
11/9/2003 408 2.057 1.987 1.19 4.053
Ave. 2.0951 2.0053 1.1880 4.0501

Table D 2. Dimensional change data of sample no. “l-A”
S.No l-A

Date time Length Width Thickness Weight
hrs (L) in (W) in (T) in (wt) g

10/22/2003 0 2.1025 2.097 1.2865 4.4403

. 10/23/2003 24 2.0865 2.062 1.2508 4.291
10/24/2003 48 2.093 2.112 1.2985 4.2882
25-Oct 72 2.1025 2.128 1.323 4.2842
10/27/2003 96 2.092 2.113 1.3325 4.2978
10/28/2003 120 2.0975 2.1155 1.3235 4.2802
10/29/2003 144 2.1002 2.0915 1.3585 4.2915
11/31/2003 192 2.0985 2.0902 1.334 4.3047
11/2/2003 240 2.114 2.122 1.3645 4.3478
11/5/2003 312 2.1085 2.0995 1.3545 4.3576
11/7/2003 360 2.105 2.0865 1.346 4.3493
11/9/2003 408 2.0915 2.082 1.338 4.3273
Ave. 2.0993 2.0999 1.3259 4.3217

 

140

 

 

Table D 3. Averaged Dimensional Changes (thickness, length and width) data

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Time Length st.dev Length Width Width st.dev. 1" Net Wt. st.dev.
(hrs) (in) net change in net change Thickness Change(g)
(in) ' (in) (in) (in)
0 2.0834 0.0269 0.0000 1.9474 0.0000 0.1317 1.2325 0.0000 0.0764
24 2.0505 0.0364 -0.0329 1.9210 -0.0264 0.1319 1.2084 -0.0241 0.0600
48 2.0543 0.0553 -0.0292 2.0001 0.0527 0.1257 1.2285 0.0040 0.0990
72 2.0634 0.0493 0.0200 2.0078 0.0604 0.1231 1.2508 0.0183 0.1022
96 2.0571 0.0413 -0.0263 2.0164 0.0690 0.1067 1.2630 0.0305 0.0983
120 2.0677 0.0384 -0.0158 2.0128 0.0654 0.1040 1.2568 0.0242 0.0944
144 2.0775 0.0417 -0.0060 2.0036 0.0562 0.1012 1.2778 0.0453 0.1142
192 2.0660 0.0402 -0.0174 1.9932 0.0458 0.1120 1.2605 0.0280 0.1039
240 2.0770 0.0392 -0.0064 2.0161 0.0687 0.1189 1.2870 0.0545 0.1096
312 2.0630 0.0368 0.0204 2.0020 0.0546 0.1172 1.2773 0.0448 0.1092
360 2.0561 0.0450 -0.0273 1.9960 0.0486 0.1135 1.2765 0.0440 0.0983
408 2.0410 0.0413 0.0424 1.9863 0.0389 0.1132 1.2640 0.0315 0.1047
Ave. 2.0631 0.0410 1.9919 0.1166 1.2569 0.0975
Dimensional Changes at 11% RH and 30C
0.0800

.3 0.0600 WW.

g» 0.0400 +Length net change

2 (in) 1

o 0-0200 l '—l—Width net change

To in

: 0.0000 ‘ i ( ) l

.3 6 0 Thickness Change

5 -0.0200 5“ (in)

E

a -0.0400

-0.0600 W

 

 

 

 

 

Time (hrs)

 

Figure Dl-a. Dimensional changes at 11% RH and 30°C.

141

 

 

wt. change at 11%RH at 30 C

 

0 t . 1 1
¥ 1 00 200 300 400 5&0

 

-0.1 W W W W W W

 

+ "- . 1
-0.15 — W ,. 1,, ave ‘
T"..Z_'a.v§;.

. Change(g)

wt
95
N
1

-0.25 -. W WWWWW W

 

 

 

-0.3

 

Time(hrs)

l ,3 - 5 L,

Figure Dl-b. Weight changes at 11% RH and 30°C.

142

Dimensional Changes and Moisture gain/loss with respect to time at 43% RH and

30°C.

Table D 4. Dimensional Changes data at 43% and 30°C.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Length
ate 10/22/03 10/23/03 10/24/03 25-Oct 10/27/03 10/28/03
s.no. hrs 0 24 8 72 96 120
43-B 2.096 2.108 2.107 2.098 2.108 2.1045
43-B-1 1.936 1.964 1.9965 1.9805 1.994 1.983
Ave. 2.016 2.036 2.05175 2.03925 2.051 2.04375
st.dev .1131 .1018 0.0781 0.0831 0.0806 0.0859
Width
ate 10/22/03 10/23/03 10/24/03 25-Oct 10/27/03 10/28/03
Is.no hrs 0 24 48 72 96 120
43-B 1.918 1.9435 1.9445 1.9535 1.936 1.964
43-B-1 2.0735 2.049 2.094 2.081 2.077 2.0615
Ave. 1.99575 1.9435 2.01925 2.01725 2.0065 2.01275
st.dev 0.1 100 .0746 .1057 .0902 0.0997 .0689
Thickness
Date 10/22/03 10/23/03 10/24/03 25-Oct 10/27/03 10/28/03
.no hrs 0 24 48 72 96 120
43-B 1.258 1.2625 1.275 1.2765 1.287 1.2925
3-B-l 1.187 1.2155 1.212 1.2145 1.219 1.2275
Ave. 1.2225 1.239 1.2435 1.2455 1.253 1.26
t.dev 0.0502 .0332 0.0445 .043 8 .0481 0.0460
wt. change
I Date 10/22/03 10/23/03 10/24/03 5-Oct 10/27/03 10/28/03
|s.no. hrs 0 24 48 72 96 120
43-B 4.1342 4.0945 4.0908 4.0915 4.0865 4.0835
43-B-1 3.9382 3.9011 3.8989 3.8974 3.8951 3.8919
Ave. 4.0362 3.9978 3.99485 3.99445 8.9908 3.9877
8t.dev 0.1386 0.1368 0.1357 .1372 .1353 .1355

 

 

 

 

 

 

 

 

 

143

 

 

 

 

(continued from Table D4)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Length
Date 10/29/2003 11/31/200311/2/2003 11/5/200311/7/2003 11/9/2003
S.no. hrs 144 192 240 312 360 408
43-B 2.0955 2.096 2.097 2.09 2.0735 2.0795
43-B-1 1.9735 1.982 1.983 1.987 1.9615 1.971
Ave. 2.0345 2.039 2.04 2.0385 2.0175 2.02525
st.dev 0.08626703 0.0806102 0.080610170072832 0.07919596 0.07672109
Width
Date 10/29/2003 11/31/200311/2/2003 11/5/200311/7/2003 11/9/2003
1s.no hrs 144 192 240 312 360 408
43-B 1.9475 1.9535 1.9555 1.935 1.9205 1.944
43-B-1 2.0635 2.095 2.093 2.0445 2.016 2.0395
Ave. 2.0055 2.02425 2.02425 1.98975 1.96825 1.99175
st.dev 0.0820 .1001 0.0972 0.0774 0.0675 .0675
Thickness
I Date 10/29/2003 11/31/200311/2/2003 11/5/200311/7/2003 11/9/2003
.no hrs 144 192 240 312 360 408
43-B 1.291 1.2865 1.2873 1.28 1.267 1.2805
43-B-1 1.2165 1.226 1.229 1.2115 1.1955 1.295
Ave. - 1.25375 1.25625 1.25815 1.24575 1.23125 1.28775
[st.dev .0527 0.0428 0.0412 .0484 0.0506 .0103
wt. change
Date 10/29/2003 11/31/200311/2/2003 11/5/200311/7/2003 11/9/2003
Is.no. hrs 144 192 240 312 360 408
43-B 4.0834 4.0843 4.0848 4.083 4.0825 4.0815
43-B-1 3.8924 3.8953 3.8952 3.8915 3.8908 3.8905
Ave. 3.9879 3.9898 3.99 3.98725 3.98665 3.986
jst.dev 0.1351 .1336 .1341 0.1354 0.1356 0.1351

 

 

 

 

 

 

 

 

144

 

 

 

 

Table D 5-D8: Net Dimensional changes and weight loss/gain at 43% RH and 30°C.

Length
Table D5: Change in length with respect to time
Net change
Date hrs Length st.dev Length
10/22/2003 0 2.0160 0.1 131 0
10/23/2003 24 2.0360 0.1018 0.020
10/24/2003 48 2.0518 0.0781 0.036
25-Oct 72 2.0393 0.0831 0.023
10/27/2003 96 2.0510 0.0806 0.035
10/28/2003 120 2.0438 0.0859 0.028
10/29/2003 144 2.0345 0.0863 0.019
1 1/31/2003 192 2.0390 0.0806 0.023
1 1/2/2003 240 2.0400 0.0806 0.024
1 1/5/2003 312 2.0385 0.0728 0.023
1 1/7/2003 360 2.0175 0.0792 0.002
1 1/9/2003 408 2.0253 0.0767 0.009
Width

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Table D 6. Change in Width with respect to time

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Net change
Date hrs Width st.dev Width
10/22/2003 0 1.9958 0.1100 0

10/23/2003 24 1.9435 0.0746 -0.0523
10/24/2003 48 2.0193 0.1057 0.0235
25-Oct 72 2.0173 0.0902 0.0214
10/27/2003 96 2.0065 0.0997 0.0107
10/28/2003 120 2.0128 0.0689 0.0170
10/29/2003 144 2.0055 0.0820 0.0097
11/31/2003 192 2.0243 0.1001 0.0285
1 1/2/2003 240 2.0243 0.0972 0.0284
1 1/5/2003 312 1.9898 0.0774 -0.0060
1 1/7/2003 360 1.9683 0.0675 -0.0276
11/9/2003 408 1.9918 0.0675 -0.0041

 

145

 

Thickness

TableD7. Change in Thickness with respect to time

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Net change
Date hrs Thickness st.dev Thickness
10/22/2003 0 1.2225 0.0502 0
10/23/2003 24 1.2390 0.0332 0.0165
10/24/2003 48 1.2435 0.0445 0.0210
25-Oct 72 1.2455 0.0438 0.0230
10/27/2003 96 1.2530 0.0481 0.0305
10/28/2003 120 1.2600 0.0460 0.0375
10/29/2003 144 1.2538 0.0527 0.0313
1 1/31/2003 192 1.2563 0.0428 0.0338
11/2/2003 240 1.2582 0.0412 0.0357
1 1/5/2003 312 1.2458 0.0484 0.0233
1 1/7/2003 360 1.2313 0.0506 0.0088
11/9/2003 408 1.2878 0.0103 0.0653
Weight Change
TableD 8. Moisture gain/loss with respect to time
Net change
Date hrs wt.(g) st.dev. wt. Change
10/22/2003 0 4.0362 0.1386 0.0000
10/23/2003 24 3.9978 0.1368 -0.03 84
10/24/2003 48 3.9949 0.1357 -0.0414
25-Oct 72 3.9945 0.1372 -0.0418
10/27/2003 96 3.9908 0.1353 -0.0454
10/28/2003 120 3.9877 0.1355 -0.0485
10/29/2003 144 3.9879 0.1351 -0.0483
11/31/2003 192 3.9898 0.1336 -0.0464
1 1/2/2003 240 3.9900 0.1341 -0.0462
11/5/2003 312 3.9873 0.1354 -0.0489
11/7/2003 360 3.9867 0.1356 -0.0496
11/9/2003 408 3.9860 0.1351 -0.0502

 

146

 

 

 

 

Dimensional changes at 43% RH and 3°C

 

 

 

 

 

 

0.08

0.06 l
E
g 0.04
g —W—W:
E 0.02 +Length ‘
2 +Width ‘
g 0 Thickness
“ l
5 .002
E
n -o.o4

-0.06 l

Time(hrs)
Figure D 2. Dimensional changes at 43% RH and 30°C.
Net Weight Change
0.0000 . . .
100 200 300 400 5130

’3 0.01001 WW WW W W.
Ti
2' 0.0200
.2
‘5
'7: -0.0400 -
3 0.0500 1

 

 

 

 

-0.0600

Time(hrs)

 

Figure D 3. Moisture gain/loss at 43% RH and 30°C.

147

 

Dimensional Changes and Moisture gain/loss with respect to time at 56% RH and

30°C.

Table D 9. Dimensional Changes data at 56% and 30°C.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Length
Date 10/22/2003 10/23/2003 10/24/2003 25—Oct 10/27/2003 10/28/2003
S.no. Time(hrs) 0 24 48 72 96 120
56—B 1.964 1.966 1.985 1.973 1.969 2.0025
56—B-1 2.03 2.048 2.0305 2.0085 1.986 2.04
Ave. 1.997 2.007 2.00775 1.9907 1.9775 2.02125
st.dev 0.0467 0.0580 0.0322 0.0251 0.0120 0.0265
Width
Date 10/22/2003 10/23/2003 10/24/2003 25-Oct 10/2 7/2003 10/2 8/2003
s.no Time(hrs 0 24 48 72 96 120
56-B 2.085 2.0888 2.09 2.0805 2.096 2.1005
56-B-l 2.0185 2.045 2.0485 2.0595 2.061 2.0885
Ave. 2.05175 2.0888 2.06925 2.07 2.0785 2.0945
st.dev 0.0470 0.0310 0.0293 0.0148 0.0247 0.0085
Thickne
55
Date 10/22/2003 10/23/2003 10/24/2003 25-Oct 10/27/2003 10/28/2003
s.no Time(hrs) 0 24 48 72 96 120
56-B 1.2455 1.2835 1.2615 1.2945 1.317 1.321
56-B-1 1.229 1.255 1.2635 1.275 1.2845 1.285
Ave. 1.23725 1.26925 1.2625 1.28475 1.30075 1.303
st.dev 0.01 17 0.0202 0.0014 0.0138 0.0230 0.0255
wt.
change
Date 10/22/2003 10/23/2003 10/24/2003 25-Oct 10/27/2003 10/28/2003
s.no. Time(hrs) 0 24 48 72 96 120
56-B 3.5927 3.5958 3.5987 3.5975 3.5956 3.6
56-B-1 3.9728 3.9752 3.9797 3.9776 3.9758 3.9791
Ave. 3.78275 3.7855 3.7892 3.78755 3.7857 3.78955
st.dev 0.2688 0.2683 0.2694 0.2688 0.2688 0.2681

 

 

 

 

 

 

 

 

148

 

 

 

 

(Continued from table D9)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Length
Date 10/29/2003 1 1/31/2003 1 1/2/2003 1 1/5/2003 1 1/7/2003 1 1/9/2003
S.no. Time(hrs) 144 l 92 240 3 12 360 408
56-B 1.989 1.99 1.9855 1.966 1.9625 1.9665
56-B-1 2.006 2.0335 2.018 1.997 1.9955 2
Ave. 1.9975 2.01 175 2.00175 1.9815 1.979 1.98325
st.dev 0.0120 0.0308 0.0230 0.0219 0.0233 0.0237
Width
Date 10/29/2003 1 1/31/2003 11/2/2003 1 1/5/2003 1 1/7/2003 1 1/9/2003
s.no Time(hrs) 144 192 240 3 12 360 408
56-B 2.0815 2.0875 2.082 2.071 2.044 2.064
56-B-l 2.041 2.0565 2.056 2.034 1.999 2.0195
Ave. 2.06125 2.072 2.069 2.0525 2.0215 2.04175
st.dev 0.0286 0.0219 0.0184 0.0262 0.0318 0.0315
Thickness
Date 10/29/2003 1 1/31/2003 11/2/2003 1 1/5/2003 1 1/7/2003 11/9/2003
5 -no Time(hrs) 144 1 92 240 3 12 360 408
561-3 1.3175 1.3625 1.3515 1.321 1.3105 1.359
56—B-1 1.271 1.2745 1.2665 1.2645 1.2465 1.266
[1 Ave. 1.29425 1.3185 1.309 1.29275 1.2785 1.3125
ll st.dev 0.0329 0.0622 0.0601 0.0400 0.0453 0.0658
wt. change
Date 10/29/2003 1 1/31/2003 11/2/2003 1 1/5/2003 1 1/7/2003 1 1/9/2003
s.no. Time(hrs) 144 192 240 3 12 360 408
56-B 3.5958 3.602 3.5987 3.5975 3.594 3.5923
56-B-1 3.9756 3.9833 3.9772 3.9748 3.9741 3.9735
Ave. 3.7857 3.79265 3.78795 3.78615 3.78405 3.7829
st.dev 0.2686 0.2696 0.2676 0.2668 0.2688 0.2695

 

149

 

 

 

 

Table D10:

Change in Length with respect to time

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Time Length st.dev Net change
Date (hrs) (in) Length
10/22/2003 0 1.9970 0.0467 0
10/23/2003 24 2.0070 0.0580 0.0100
10/24/2003 48 2.0078 0.0322 0.0108
25-Oct 72 1.9908 0.0251 -0.0062
10/27/2003 96 1.9775 0.0120 -0.0195
10/28/2003 120 2.0213 0.0265 0.0243
10/29/2003 144 1.9975 0.0120 0.0005
11/31/2003 192 2.0118 0.0308 0.0148
11/2/2003 240 2.0018 0.0230 0.0047
11/5/2003 312 1.9815 0.0219 -0.0155
1 1/7/2003 360 1.9790 0.0233 -0.0180
1 1/9/2003 408 1.9833 0.0237 -0.0138
Table D11. Change in Width with respect to time
Time Width Net change
Date (hrs) (in) st.dev Width
10/22/2003 0 2.0518 0.0470 0
10/23/2003 24 2.0888 0.0310 0.0370
10/24/2003 48 2.0693 0.0293 0.0175
25-Oct 72 2.0700 0.0148 0.0182
10/27/2003 96 2.0785 0.0247 0.0267
10/28/2003 120 2.0945 0.0085 0.0427
10/29/2003 144 2.0613 0.0286 0.0094
1 1/31/2003 192 2.0720 0.0219 0.0202
1 1/2/2003 240 2.0690 0.0184 0.0172
11/5/2003 312 2.0525 0.0262 0.0007
11/7/2003 360 2.0215 0.0318 -0.0303
11/9/2003 408 2.0418 0.0315 -0.0101

 

 

 

 

 

150

 

 

Table D12. Change in Thickness with respect to time

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Time Net change
Date (hrs) Thickness st.dev Thickness
10/22/2003 0 1.2373 0.01 17 0
10/23/2003 24 1.2693 0.0202 0.0320
10/24/2003 48 1.2625 0.0014 0.0253
25-Oct 72 1.2848 0.0138 0.0475
10/27/2003 96 1.3008 0.0230 0.0635
10/28/2003 120 1.3030 0.0255 0.0658
10/29/2003 144 1.2943 0.0329 0.0570
11/31/2003 192 1.3185 0.0622 0.0813
1 1/2/2003 240 1.3090 0.0601 0.0718
11/5/2003 312 1.2928 0.0400 0.0555
1 1/7/2003 360 1.2785 0.0453 0.0413
11/9/2003 408 1.3125 0.0658 0.0753

 

Table D13. Moisture gain/loss change with respect to time

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Time Weight change Net wt.
Date firs) (g) st.dev Change(g)
10/22/2003 0 3.7828 0.2688 0
10/23/2003 24 3.7855 0.2683 0.0027
10/24/2003 48 3.7892 0.2694 0.0064
25-Oct 72 3.7876 0.2688 0.0048
10/27/2003 96 3.7857 0.2688 0.0029
10/28/2003 120 3.7896 0.2681 0.0068
10/29/2003 144 3.7857 0.2686 0.0029
1 1/31/2003 192 3.7927 0.2696 0.0099
1 1/2/2003 240 3.7880 0.2676 0.0051
11/5/2003 312 3.7862 0.2668 0.0034
1 1/7/2003 360 3.7841 0.2688 0.0012
1 1/9/2003 408 3.7829 0.2695 0.0001

 

151

 

 

 

Dimensional changes at 56% RH and 30°C

 

0.1000 _
0.0800-1W” W W WW WW W WW W4
0.0600 ’

0.0400 1; __ fit; WWW W— W — WWW«
0.0200 « l y \
0.0000 ' T v . \Ta W_
{10200 ,, "30“ 2Q_ 711193,,400 500 1

.7— 7 T 1
-0.0400 *

 

+ Length
—I— Width
-, chknese-

    

 

 

 

Dlmenslonal changesfln)

 

 

Time(hrs)

 

Figure D 4. Dimensional changes at 56% RH and 30°C.

 

Net weight Change at 56% RH and 30°C

0.012
0.01

0.008
1

0.006 I + net wt. Change(g) ‘5
0.004

0.002

Net change In weight (g)

 

0 100 200 300 400 500
Time (hrs)

 

Figure D5 . Moisture gain/loss at 56% RH and 30°C.

152

Dimensional Changes and Moisture gain/loss with respect to time at 75% RH and

30°C.

Table D14. Dimensional Changes data at 75% and 30°C.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Length
Date 10/22/03 10/23/2003 10/24/2003 10/25/2003 10/27/2003 10/28/03
S.no. hrs 0 24 48 72 96 120
75—B 1.968 1.975 1.998 1.966 1.998 1.983
75-B-1 2.043 2.023 2.0245 2.0245 2.028 2.0195
Ave. 2.0055 1.999 2.01125 1.99525 2.013 2.00125
St.dev. St.dev. 0.0530 0.0339 0.0187 0.0414 0.0212 0.0258
Width
Date 10/22/2003 10/23/2003 10/24/2003 25-Oct 10/27/2003 10/28/2003
hrs 0 24 48 72 96 120
s.no
75-B 2.0795 2.11 2.1259 2.107 2.1235 2.115
75-B-1 2.048 2.12 2.1281 2.125 2.1395 2.108
Ave. 2.06375 2.11 2.127 2.116 2.1315 2.1115
St.dev. 0.0223 0.0071 0.0016 0.0127 0.0113 0.0049
Thickne
ss
10/22/2003 10/23/2003 10/24/2003 25-Oct 10/27/2003 10/28/2003
hrs 0 24 48 72 96 120
s.no
75-B 1.318 1.5615 1.5856 1.6215 1.6585 1.6625
75-B-1 1.249 1.4275 1.48 1.482 1.515 1.5285
Ave. 1.2835 1.4945 1.5328 1.55175 1.58675 1.5955
St.dev. 0.0488 0.0948 0.0747 0.0986 0.1015 0.0948
Weight chan e
F 10/22/2003 10/23/2003 10/24/2003 25-Oct 10/2 7/2003 10/28/2003
lliwt. change hrs 0 24 48 72 96 120
s.no.
75-B 4.0916 4.2395 4.2406 4.2558 4.2714 4.2595
75-B-1 4.1859 4.3341 4.346 4.349 4.3638 4.3521
Ave. 4.13875 4.2868 4.2933 4.3024 4.3176 4.3058
St.
de
v 0.0667 0.0669 0.0745 0.0659 0.0653 0.0655

 

 

 

 

 

 

 

 

 

153

 

 

 

 

(Continued from table D14)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Length
Date 10/29/2003 11/31/2003 11/2/2003 11/5/2003 11/7/2003 11/9/2003
S.no. hrs 144 192 240 312 360 408
7513 1.9715 1.971 1.963 1.964 1.96 1.9595
75-B-l 2.018 2.0105 2.0015 2.005 1.996 1.9965
Ave. 1.99475 1.99075 1.98225 1.9845 1.978 1.978
St.dev
St.dev. 0.0329 0.0279 0.0272 0.0290 0.0255 0.0262
Width
Date 10/29/2003 11/31/2003 11/2/2003 11/5/2003 11/7/2003 11/9/2003
hrs 144 192 240 3 12 360 408
7513 2.1125 2.1795 2.1115 2.103 2.1105 2.0895
75-B-1 2.08 2.142 2.109 2.0975 2.0775 2.0795
Ave. 2.09625 2.16075 2.11025 2.10025 2.094 2.0845
St.dev
0.0230 0.0265 0.0018 0.0039 0.0233 0.0071
Thickness
Date 10/29/2003 11/31/2003 11/2/2003 11/5/2003 11/7/2003 11/9/2003 I
hrs 144 192 240 312 360 408 II
7513 1.6815 1.705 1.687 1.6985 1.6695 1.6725 [1
758.1 1.531 1.535 1.5485 1.5845 1.505 1.5585 1
Ave. 1.60625 1.62 1.61775 1.6415 1.58725 1.6155 1
St.dev
0.1064 0.1202 0.0979 0.0806 0.1163 0.0806
Weight change
‘wt. change Date 10/29/2003 11/31/2003 11/2/2003 11/5/2003 11/7/2003 11/9/2003
s.no. hrs 144 192 240 312 360 408
75.8 4.2696 4.277 4.2716 4.2758 4.2686 4.268
75-B-1 4.3575 4.3717 4.3681 4.3702 4.3642 4.3644
Ave. 4.31355 4.32435 4.31985 4.323 4.3164 4.3162
St.dev
0.0622 0.0670 0.0682 0.0668 0.0676 0.0682

 

 

154

Table D15. Change in Length with respect to time

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Time Length (in) St.dev. Net change

hrs Length (in)
0 2.0055 0.0530 0.0000
24 1.9990 0.0339 —0.0065
48 2.01 13 0.0187 0.0057
72 1.9953 0.0414 -0.0103
96 2.0130 0.0212 0.0075
120 2.0013 0.0258 -0.0042
144 1.9948 0.0329 -0.0108
192 1.9908 0.0279 -0.0148
240 1.9823 0.0272 -0.0233
312 1.9845 0.0290 -0.0210
360 1.9780 0.0255 -0.0275
408 1.9780 0.0262 -0.0275

 

 

Table 16: Change in Width with respect to time

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Time Width St.dev. et change
hrs (Width)(in)
0 2.0638 0.0223 0.0000
24 2.1 100 0.0071 0.0462
48 2.1270 0.0016 0.0632
72 2.1160 0.0127 0.0522
96 2.1315 0.0113 0.0677
120 2.1 1 15 0.0049 0.0478
144 2.0963 0.0230 0.0325
192 2.1608 0.0265 0.0970
240 2.1103 0.0018 0.0465
312 2.1003 0.0039 0.0365
360 2.0940 0.0233 0.0303
408 2.0845 0.0071 0.0208

 

 

 

 

155

 

Table D17. Change in Thickness with respect to time

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Time Thickness St.dev. Net change
hrs (in) (in) thicknessQn)i
0 1.2835 0.0488 0.0000
24 1.4945 0.0948 0.2110
48 1.5328 0.0747 0.2493
72 1.5518 0.0986 0.2683
96 1.5868 0.1015 0.3033
120 1.5955 0.0948 0.3120
144 1.6063 0.1064 0.3228
192 1.6200 0.1202 0.3365
240 1.6178 0.0979 0.3343
312 1.6415 0.0806 0.3580
360 1.5873 0.1163 0.3038
408 1.6155 0.0806 0.3320

 

 

 

 

Table D18. Moisture gain/loss with respect to time

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Time Wt.change St.dev. Net wt.change

hrs (8) (g)

0 4.1388 0.0667 0.0000
24 4.2868 0.0669 0.1481
48 4.2933 0.0745 0.1546
72 4.3024 0.0659 0.1637
96 4.3176 0.0653 0.1789
120 4.3058 0.0655 0.1671
144 4.3136 0.0622 0.1748
192 4.3244 0.0670 0.1856
240 4.3199 0.0682 0.1811
312 4.3230 0.0668 0.1843
360 4.3164 0.0676 0.1777
408 4.3162 0.0682 0.1775

 

156

 

 

Dimensioal Change(in)

0.4000

0.3500 ~
0.3000 .

0.2500

0.2000 ~

0.1500
0.1000
0.0500
0.0000

Dimensional changes(in)

 

 

,,_ £17,,

+ (Width)(in)
thickness(in)

 

 

 

-0.0500 0—190—499——300———499~——500

Time(hrs)

 

Figure D6. Dimensional changes at 75% RH and 30°C.

157

 

Net weight Change at 75% RH and 30°C

 

 

n .

1*:nst wt Clarissa

 

 

 

 

 

1 O 100 200 300 400 500
i Time (hrs)

Figure D 7 Moisture gain/loss at 75% RH and 30°C.

158

 

 

Dimensional Changes and Moisture gain/loss with respect to time at 84% RH and

30°C.

Table D19. Dimensional Changes data and moisture gain/loss at 84% and 30°C.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Length
10/22/2003 10/23/2003 10/24/2003 25-Oct 10/27/2003 10/28/2003
Time hrs 0 24 48 72 96 120
84-B 2.0545 2.0315 2.004 1.9835 1.901 1.91
84-B-l 1.986 2.002 1.984 1.9835 1.876 1.8796
Ave. 2.027875 2.035 2.0225 2.009375 1.9495 1.950525
st.dev. [st.dev. 0.0279 0.0213 0.0345 0.0270 0.0629 0.0582
Width
date 10/22/2003 10/23/2003 10/24/2003 25-Ocl 10/27/2003 10/28/2003
Time hrs 0 24 48 72 96 120
84-B 2.097 2.1 125 2.078 2.0405 1.98 1.9987
84-B-1 2.062 2.103 2.0685 2.055 2.0275 2.071
Ave. 2.02025 2.062125 2.048625 2.039 2.007125 2.023675
[st.dev. 0.07752298 0.07469302 0.067005014 0.04793094 0.053381147 0.07143383
Thickness
Time date 10/22/2003 10/23/2003 10/24/2003 25-Oct 10/27/2003 10/28/2003
hrs 0 24 48 72 96 120
84-B 1.271 1.5305 1.5845 1.6165 1.66 1.6875
84-B-1 1.319 1.6175 1.6685 1.712 1.7765 1.7545
Ave.1" 1.295 1.574 1.6265 1.66425 1.71825 1.721
1" st.dev. 0.0339 0.0615 0.0594 0.0675 0.0824 0.0474

 

 

 

 

 

 

 

159

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

wt. change
Time date 10/22/2003 10/23/2003 10/24/2003 25-Oct 10/27/2003 10/2 8/2003
hrs 0 24 48 72 96 120
84-B 3.7139 3.9096 3.9425 3.9574 3.9975 3.9886
84—B-1 4.0886 4.3005 4.3274 4.3452 4.3936 4.3837
ave. 1"

ave.l" thickl thick 3.90125 4.10505 4.13495 4.1513 4.19555 4.18615
istdev. 0.2650 0.2764 0.2722 0.2742 0.2801 0.2794

 

 

(Continued from Table D19)

160

 

Length

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

10/29/2003 1 1/31/2003 11/2/2003 1 1/5/2003 1 1/7/2003 11/9/2003
Time hrs 144 192 240 3 12 360 408
84-B 1.8785 1.877 1.784 1.7625 1.724 1.7155
84-B-1 1.8335 1.8 1.7565 1.738 1.718 1.7065
Ave. 1.92625 1.920875 1.843125 1.825 1.8075 1.800375
st.dev. st.dev. 0.0730 0.0902 0.0746 0.0770 0.0878 0.0897
Width
date 10/29/2003 1 1/31/2003 1 1/2/2003 11/5/2003 1 1/7/2003 1 1/9/2003
Time hrs 144 192 240 3 12 360 408
84-B 2.097 2.1 125 2.078 2.0405 1.98 1.9987
84-B-1 2.062 2.103 2.0685 2.055 2.0275 2.071
Ave. 2.0795 2.10775 2.07325 2.04775 2.00375 2.03485
st.dev. 0.0175 0.00475 0.00475 0.00725 0.02375 0.03615
Thicknes
S
Time date 10/29/2003 1 1/31/2003 1 1/2/2003 1 1/5/2003 1 1/7/2003 1 1/9/2003
84-B hrs 144 192 240 3 12 360 408
84-B-1 1.271 1.5305 1.5845 1.6165 1.66 1.6875
Ave.1" 1.319 1.6175 1.6685 1.712 1.7765 1.7545
1" 1.295 1.574 1.6265 1.66425 1.71825 1.721
st.dev. 0.0339 0.0615 0.0594 0.0675 0.0824 0.0474
wt. change
Time date 10/29/2003 1 1/31/2003 1 1/2/2003 1 1/5/2003 1 1/7/2003 1 1/9/2003
84-B hrs 144 192 240 3 12 360 408
84cB-1 3.7139 3.9096 3.9425 3.9574 3.9975 3.9886
ave. 1"
thick 4.0886 4.3005 4.3274 4.3452 4.3936 4.3837
ave. 1"
thick 3.90125 4.10505 4.13495 4.1513 4.19555 4.18615
st.dev. 0.2650 0.2764 0.2722 0.2742 0.2801 0.2794

 

 

 

 

 

 

 

 

161

 

 

 

 

Table D 20. Change in Length with respect to time

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Time Length Net Change

Date (hrs) (in) st.dev. Length(in)
10/22/2003 0 2.0279 0.0279 0.0000
10/23/2003 24 2.0350 0.0213 0.0071
10/24/2003 48 2.0225 0.0345 -0.0054
25-Oct 72 2.0094 0.0270 -0.0185
10/27/2003 96 1.9495 0.0629 -0.0784
10/28/2003 120 1.9505 0.05 82 -0.0773
10/29/2003 144 1.9263 0.0730 -0. 1016
1 1/31/2003 192 1.9209 0.0902 -0. 1070
1 1/2/2003 240 1.8431 0.0746 -0.1848
1 1/5/2003 312 1.8250 0.0770 -O.2029
11/7/2003 360 1.8075 0.0878 -0.2204
1 1/9/2003 408 1.8004 0.0897 -0.2275

Table D 21. Change in Width with respect to time
Time Width Net chan e ‘

Date (hrs) (in) st.dev Width in)
10/22/2003 0 2.0203 0.0775 0.0000
10/23/2003 24 2.0621 0.0747 0.0419
10/24/2003 48 2.0486 0.0670 0.0284
25-Oct 72 2.0390 0.0479 0.0187
10/27/2003 96 2.0071 0.0534 -0.0131
10/28/2003 120 2.0237 0.0714 0.0034
10/29/2003 144 2.0229 0.0608 0.0026
1 1/31/2003 192 1.9941 0.0666 -0.0261
1 1/2/2003 240 1.941 1 0.0707 -0.0791
11/5/2003 312 1.9193 0.0767 -0.1010
1 1/7/2003 360 1.9036 0.0798 -0.1166
1 1/9/2003 408 1.8876 0.0825 -0. 1326

 

 

 

 

 

 

 

162

Table D 22. Change in Thickness with respect to time

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Time Thickness Net change
Date (hrs) ' (in) st.dev. Thickness(in)
10/22/2003 0 1.2950 0.0339 0.0000
10/23/2003 24 1.5740 0.0615 0.2790
10/24/2003 48 1.6265 0.0594 0.3315
25-Oct 72 1.6643 0.0675 0.3693
10/27/2003 96 1.7183 0.0824 0.4233
10/28/2003 120 1.7210 0.0474 0.4260
10/29/2003 144 1.7255 0.0495 0.4305
11/31/2003 192 1.7450 0.0396 0.4500
1 1/2/2003 240 1.6688 0.0442 0.3738
11/5/2003 312 1.6610 0.0474 0.3660
11/7/2003 360 1.6560 0.0431 0.3610
11/9/2003 408 1.6788 0.0187 0.3838
Table 23: Moisture gain/loss with respect to time
Time Wt. Change st.dev. Net wt.chan e
Date (hrS) (g) (g)

10/22/2003 0 3.9013 0.2650 0.0000
10/23/2003 24 4.1051 0.2764 0.2038
10/24/2003 48 4.1350 0.2722 0.2337
25-Oct 72 4.1513 0.2742 0.2501
10/27/2003 96 4.1956 0.2801 0.2943
10/28/2003 120 4.1862 0.2794 0.2849
10/29/2003 144 4.1909 0.2760 0.2896
1 1/31/2003 192 4.1987 0.2790 0.2975
1 1/2/2003 240 4.2188 0.2782 0.3175
1 1/5/2003 312 4.2149 0.2788 0.3136
11/7/2003 360 4.2108 0.2747 0.3095
1 1/9/2003 408 4.2133 0.2757 0.3120

 

 

 

 

 

 

163

 

 

 

net dimensional change(ln)

 

Dimensional Changes at 84% RH and 30°C

 

Net weight Change(g

 

 

 

Time (hrs)

 

Figure D9. Moisture gain/loss 84% RH and 30°C.

164

 

l
l
l
1
l

 
  

+ Length(in) ;
—I—- Width(in) l

Thickness-1" i
w l

 

 

l
__ _ _ _1
+ Net wt.Change 1‘

l
l
l
l
l
1
l
4

Dimensional Changes and Moisture gain/loss with respect to time at 89% RH and

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

30°C.
Table D 24. Dimensional Changes data and moisture gain/loss at 89% and
30°C.
Length
Date 10/22/200310/23/2003 10/24/2003 25-Oct 10/27/2003 10/28/2003
s.no. Time(hrs) 0 24 48 72 96 120
89-8 2.0105 1.3595 1.2665 1.2515 1.2483 1.231
89-B-1 2.1025 1.422 1.298 1.2835 1.2785 1.2545
Ave. 2.0565 1.39075 1.28225 1.2675 1.2634 1.24275
st.dev. 0.0650 0.0441 0.0222 0.0226 0.0213 0.0166
Width
Date 10/22/200310/23/2003 10/24/2003 25-Oct 10/27/2003 10/28/2003
s.no Time(hrs) 0 24 48 72 96 120
89-B 1.9725 1.7795 1.715 1.694 1.685 1.6105
89-B-1 1.9805 1.3075 1.3012 1.2926 1.3875 1.385
Ave. 1.9765 1.5435 1.5081 1.4933 1.53625 1.49775
st.dev. 0.005 0.33 0.29 0.28 0.210 0.1594
Thickne
SS
Date 10/22/200310/23/2003 10/24/2003 25-Oct 10/27/2003 10/28/2003
s.no Time(hrs) O 24 48 72 96 120 ,
89-B 1.3195 1.3025 1.2375 1.2815 1.2365 1.2255 ;
89-B-1 1.2896 1.2735 1.263 1.3205 1.316 1.273 1
Ave. 1.30455 1.288 1.25025 1.301 1.27625 1.24925 1
st.dev. 0.02 0.02 0.018 0.027 0.056 0.033 I
wt.
01999
[ Date 10/22/200310/23/2003 10/24/2003 25—Oct 10/27/200310/28/20081
Is.no. Time(hrs) 0 24 4 72 96 120|
[896 3.9087 4.3288 4.364 4.3813 4.5213 4.5181
5943-1 4.0355 4.4966 4.5325 4.5514 4.6855 4.673]
lAve. 3.9721 4.4127 4.44825 4.46635 4.6034 4.5955]
I st.dev. 0.09 0.118 0.12 0.12 0.12 0.11 |

 

 

 

 

 

 

 

 

165

(continued from table D24)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Length
Date 10/29/2003 1 1/31/2003 1 1/2/2003 1 1/5/2003 11/7/2003 11/9/2003
S.no. Time(hrs) 144 192 240 3 12 360 408
89-B 1.221 1.2295 1.2165 1.21 1 1.205 1.209
89-B-1 1.222 1.245 1.2295 1.2156 1.2365 1.239
Ave. 1.2215 1.23725 1.223 1.2133 1.22075 1.224
st.dev. 0.0007 0.01 10 0.0092 0.0033 0.0223 0.0212
Width
Date 10/29/2003 1 1/31/2003 1 1/2/2003 1 1/5/2003 11/7/2003 1 1/9/2003
s.no Time(hrs) 144 192 240 312 360 408
89-B 1.5925 1.651 1.6075 1.5885 1.5465 1.5605
89-B-1 1.372 1.379 1.364 1.451 1.399 1.42
Ave. 1.48225 1.515 1.48575 1.51975 1.47275 1.49025
st.dev. 0.1559 0.1923 0.1722 0.0972 0.1043 0.0993
Thickness
Date 10/29/2003 1 1/31/2003 11/2/2003 1 1/5/2003 11/7/2003 1 1/9/2003
s.no Time(hrs) 144 192 240 3 12 360 408
89-B 1.2315 1.256 1.2385 1.21 1.1654 1.2395
89-B-1 1.236 1.291 1.279 1.2085 1.198 1.2635
Ave. 1.23375 1.2735 1.25875 1.20925 1.1817 1.2515
st.dev. 0.0032 0.0247 0.0286 0.001 1 0.0231 0.0170
wt. change
Date 10/29/2003 1 1/31/2003 1 1/2/2003 1 1/5/2003 1 1/7/2003 11/9/2003
s.no. Time(hrs) 144 192 240 3 12 360 408
89-B 4.5572 4.5542 4.6219 4.6083 4.6038 4.613
89-B-1 4.7035 4.732 4.7888 4.7874 4.789 4.785
Ave. 4.63035 4.6431 4.70535 4.69785 4.6964 4.699
st.dev. 0.1034 0.1257 0.1180 0.1266 0.1310 0.1216

 

 

 

 

 

 

 

 

 

166

 

 

 

 

Table D 25. Change in Length with respect to time

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Net changg_
Date Time(hrs) Lenfl st.dev. ngth
10/22/2003 0 2.0565 0.065054 0
10/23/2003 24 1.39075 0.044194 -0.6658
10/24/2003 48 1.28225 0.022274 -0.7743
25-Oct 72 1.2675 0.022627 -0.7890
10/27/2003 96 1.2634 0.021355 -0.7931
10/28/2003 120 1.24275 0.016617 -0.8 138
10/29/2003 144 1.2215 0.000707 -0.8350
11/31/2003 192 1.23725 0.01096 -0.8193
1 1/2/2003 240 1.223 0.009192 -0.8335
11/5/2003 312 1.2133 0.003253 -O.8432
1 1/7/2003 360 1.22075 0.022274 -0.8358
1 1/9/2003 408 1.224 0.021213 -0.8325
Table D26. Change in Width with respect to time
Net change
Date Time(hrs) Widt st.dev. Width
10/22/2003 0 1.9765 0.0057 0
10/23/2003 24 1 .5435 0.3338 -0.433
10/24/2003 48 1 .5081 0.2926 -0.4684
25-Oct 72 1 .4933 0.2838 -0.4832
10/27/2003 96 1 .53625 0.2104 -0.44025
10/28/2003 120 1 .49775 0.1595 -0.47875
10/29/2003 144 1 .48225 0.1559 -0.49425
11/31/2003 192 1.515 0.1923 -0.4615
1 1/2/2003 240 1 .48575 0.1722 -0.49075
1 1/5/2003 312 1 .51975 0.0972 -0.45675
1 1/7/2003 360 1 .47275 0.1043 -0.50375
1 1/9/2003 408 1 .49025 0.0993 -0.48625

 

 

 

 

 

 

167

 

 

 

Table D27. Change in Width with respect to time

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Time(hrs) Width Net change
Date (hrs) (inL st.dev. Width(in)
10/22/2003 0 1.9765 0.0057 0
10/23/2003 24 1.5435 0.3338 -0.4330
10/24/2003 48 1.5081 0.2926 -0.4684
25-Oct 72 1.4933 0.2838 -0.4832
10/27/2003 96 1.5363 0.2104 -0.4403
10/28/2003 120 1.4978 0.1595 -0.4788
10/29/2003 144 1.4823 0.1559 -0.4943
11/31/2003 192 1.5150 0.1923 -0.4615
1 1/2/2003 240 1.4858 0.1722 -0.4908
1 1/5/2003 312 1.5198 0.0972 -0.4568
1 1/7/2003 360 1.4728 0.1043 -0.5038
1 1/9/2003 408 1.4903 0.0993 -0.4863
Table D28. Moisture gain/loss with respect to time
Time (hrs) Thickness Net change
Date (hrs) (in) st.dev. Thickness Q)
10/22/2003 0 1.3046 0.0211 0
10/23/2003 24 1.2880 0.0205 -0.0166
10/24/2003 48 1.2503 0.0180 -0.0543
25-Oct 72 1.3010 0.0276 -0.0035
10/27/2003 96 1.2763 0.0562 -0.0283
10/28/2003 120 1.2493 0.0336 -0.0553
10/29/2003 144 1.2338 0.0032 -0.0708
11/31/2003 192 1.2735 0.0247 -0.0311
11/2/2003 240 1.2588 0.0286 -0.0458
11/5/2003 312 1.2093 0.0011 -0.0953
11/7/2003 360 1.1817 0.0231 -0. 1229
11/9/2003 408 1.2515 0.0170 -0.0531

 

 

 

 

 

 

168

 

 

 

i Dimensional Changes at 89%RH and 30°C

 

l
i 0.0000 '9‘ r 4 t v

 

 

 

 

 

 

 

 

 

 

 

 

? -0.1000 —— -.__ 100 ——200 e 4300 —— ——400 500
‘5' _ ___.
d)
U
c , 7 .
2 M ‘ + Length
‘7: +Width
5 Thickness
'3 — *’ “—‘"
C
43 _ 2
.15.
o
1
Figure D10. Dimensional changes at 89% RH and 30°C.
1
1 Net Wt.Change at 89% RH and 30C
1
1+ NetWt:.9rw;ge<9>

Net Weight gain (9)

 

 

 

 

0 100 200 300 400 500
Time (hrs)

 

Figure D 11. Moisture gain/loss at 89% RH and 30°C.

169

Dimensional Changes and Moisture gain/loss with respect to time at 95% RH and

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

30°C.
Table D29. Dimensional Changes data and moisture gain/ loss at 95% and
30°C.
Length
10/22/2003 10/23/2003 10/24/2003 25-Oct 10/27/2003 10/28/2003
S.no. Time(hrs) 0 24 48 72 96 120
95-8 2.017 1.298 1.2525 1.2155 1.1575 1.1495
95-B-1 2.0675 1.244 1.2225 1.189 1.1635 1.1205
Ave. Length 2.04225 1.271 1.2375 1.20225 1.1605 1.135
St Dev. 0.0357 0.0382 0.0212 0.0187 0.0042 0.0205
Width
date 10/22/2003 10/23/2003 10/24/2003 25-Oct 10/27/2003 10/28/2003
s.no hrs 0 24 48 72 96 120
95—B 2.114 1.521 1.443 1.415 1.393 1.3575
95-B-1 1.965 1.6395 1.6015 1.564 1.5615 1.548
Ave. Width 2.0395 1.58025 1.52225 1.4895 1.47725 1.45275
St Dev. 0.1054 0.0838 0.1121 0.1054 0.1191 0.1347
Thickne
53
Days 10/22/2003 10/23/2003 10/24/2003 25-Oct 10/27/2003 10/28/2003
s.no
95-B 1.293 1.3205 1.267 1.2255 1.2005 1.1985
95-B-1 1.2435 1.2995 1.223 1.2185 1.2035 1.2
Thicknes
Ave. S 1.26825 1.31 1.245 1.222 1.202 1.19925
St Dev. 0.0350 0.0148 0.0311 0.0049 0.0021 0.0011
wt.
change
Days 110/22/2003 10/23/2003 10/24/2003 25-Oct 10/27/2003 10/28/2003
s.no.
95-B 3.827 4.2351 4.2606 4.326 4.4378 4.4707
95-B-1 3.8273 4.2501 4.3056 4.345 4.4773 4.469
Wt.
Ave. Change 3.82715 4.2426 4.2831 4.3355 4.45755 4.46985
St Dev. 0.0002 0.0106 0.0318 0.0134 0.0279 0.0012

 

 

 

 

 

 

 

 

 

170

 

 

 

 

(continued from Table D29)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Length .
10/29/2003 1 1/31/2003 1 1/2/2003 1 1/5/2003 1 1/7/2003 1 1/9/2003
s.no. Timefitrs) 144 192 240 312 360 408
95-B 1.146 1.1435 1.176 1.17 1.1685 1.167
95—B-1 1.112 1.1085 1.2445 1.217 1.204 1.1885
Ave. Length 1.129 1.126 1.21025 1.1935 1.18625 1.17775
St Dev. 0.0240 0.0247 0.0484 0.0332 0.0251 0.0152
Width
date 10/29/2003 1 1/31/2003 1 1/2/2003 11l5/2003 1 1 /7/2003 1 1/9/2003
s.no hrs 144 192 240 312 360 408
95-B 1.3555 1.3825 1.453 1.419 1.381 1.3885
95-B-1 1.53 1.537 1.5495 1.5245 1.4965 1.5365
Ave. Width 1.44275 1.45975 1.50125 1.47175 1.43875 1.4625
St Dev. 0.1234 0.1092 0.0682 0.0746 0.0817 0.1047
Thickne
ss
Days 10/29/2003 1 1/31/2003 11/2/2003 1 1/5/2003 1 1/7/2003 1 1/9/2003
s.no 144 192 240 312 360 408
95-B 1.192 1.196 1.216 1.21 1.218 1.2165
95-B-1 1.186 1.178 1.1935 1.19 1.2075 1.209
Thicknes
Ave. 3 1.189 1.187 1.20475 1.2 1.21275 1 .21275
St Dev. 0.0042 0.0127 0.0159 0.0141 0.0074 0.0053
wt.
change
1 Days 10/29/2003 1 1/31/2003 11/2/2003 1 1/5/2003 1 1/7/2003 1 1/9/2003
s.no.
95—B 4.4739 4.4985 4.6515 4.6089 4.668 4.6593
95—B-1 4.4639 4.4721 4.6433 4.592 4.7501 4.6593
Wt.
Ave. Change 4.4689 4.4853 4.6474 4.60045 4.70905 4.6593
St Dev. 0.0071 0.0187 0.0058 0.0120 0.0581 0.0000

 

 

 

 

 

 

 

 

 

171

 

 

 

 

Table D 30. Change in Length with respect to time

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Net change
Date Time(hrs) Length St Dev. (length)
10/22/2003 0 2.0423 0.0357 0
10/23/2003 24 1.2710 0.0382 -0.7713
10/24/2003 48 1.2375 0.0212 -0.8048
25-Oct 72 1.2023 0.0187 -0.8400
10/27/2003 96 1 . 1605 0.0042 -0.8818
10/28/2003 120 1.1350 0.0205 -0.9073
10/29/2003 144 1.1290 0.0240 -0.9133
1 1/31/2003 192 1.1260 0.0247 -0.9163
11/2/2003 240 1.2103 0.0484 -0.8320
11/5/2003 312 1.1935 0.0332 -0.8488
11/7/2003 360 1.1863 0.0251 -0.8560
1 1/9/2003 408 1.1778 0.0152 -0.8645
Table D 31: Change in Width with respect to time
Time Width Net change
Date (hrs) (in) St Dev.(width) width (in)
10/22/2003 0 2.0395 0.1054 0
10/23/2003 24 1.5803 0.0838 -0.4593
10/24/2003 48 1.5223 0.1121 -0.5173
25-Oct 72 1.4895 0.1054 -0.5500
10/27/2003 96 1.4773 0.1191 -0.5623
10/28/2003 120 1.4528 0.1347 -0.5868
10/29/2003 144 1.4428 0.1234 -0.5968
11/31/2003 192 1.4598 0.1092 -0.5798
1 1/2/2003 240 1.5013 0.0682 -0.5383
11/5/2003 312 1.4718 0.0746 -0.5678
11/7/2003 360 1.4388 0.0817 -0.6008
1 1/9/2003 408 1.4625 0.1047 -0.5770

 

 

 

 

 

172

 

 

Table D32. Change in Thickness with respect to time

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Time Thickness Net change
Date (hrs) (in) St Dev. thickness(in)
10/22/2003 0 1.2683 0.0350 0
10/23/2003 24 1.3100 0.0148 0.0417
10/24/2003 48 1.2450 0.031 1 -0.0233
25-Oct 72 1.2220 0.0049 -0.0463
10/27/2003 96 1.2020 0.0021 -0.0663
10/28/2003 120 1.1993 0.001 1 -0.0691
10/29/2003 144 1.1890 0.0042 -0.0793
11/31/2003 192 1.1870 0.0127 -0.0813
1 1/2/2003 240 1.2048 0.0159 -0.0636
1 1/5/2003 312 1.2000 0.0141 -0.0683
1 1/7/2003 360 1.2128 0.0074 -0.0556
11/9/2003 408 1.2128 0.0053 -0.0556
Table 33: Moisture gain/loss with respect to time
Net wt.
Time Wt. Change change
Date (hrs) (g) St Dev. (g)
10/22/2003 0 3.8272 0.0002 0
10/23/2003 24 4.2426 0.0106 0.4154
10/24/2003 48 4.2831 0.0318 0.4560
25-Oct 72 4.3355 0.0134 0.5084
10/27/2003 96 4.4576 0.0279 0.6304
10/28/2003 120 4.4699 0.0012 0.6427
10/29/2003 144 4.4689 0.0071 0.6418
11/31/2003 192 4.4853 0.0187 0.6582
1 1/2/2003 240 4.6474 0.0058 0.8203
11/5/2003 312 4.6005 0.0120 0.7733
11/7/2003 360 4.7091 0.0581 0.8819
1 1/9/2003 408 4.6593 0.0000 0.8322

 

 

173

 

 

 

 

 

 

 

 

 

 

Dimensioal changes at 95%RH and 30°C

1

0.2000 , _ ,- ,. i

% 0.0000 [ . r . 4 1

8' 02000 , ' )0 i
g + Net Change(length)
7' -0.4000 < 7‘ + Net change(width)

5 _0_6000 - _ , . . Njflwfliflmfifl

E 1

E -0.8000 9 ‘

E 1

-1.0000 ‘

Figure D 12. Dimensional changes at 95% RH and 30°C.

 

P
V

net wt. change ( )

 

0 100

200

300
Time(hrs)

400 500

 

Net weight change at 95% Rh and 30°C

+ Net wt. change
———'_’ ' __ ' l

 

Figure D13. Moisture loss/gain at 95% RH and 30°C.

174

 

 

APPENDIX C

MOISTURE SENSITIVITY 0G GREEN CELL® FOAM

Initial Moisture Content "Mi" calculations

Table M . Initial moisture Content Calculations of Green Cell® foam

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

after Wt. of
Sample Dish Wt Wt.of Wt. of heating product Wt. of Mi
No. (g) product+ roduct before dish after product after (g)
dish before heating (g) heating (g) heating(g)
heating
ssl 1.2711 2.0412 0.7701 4.6269 1.9274 0.6563 0.1734
952 1.2745 2.0023 0.7278 4.8564 1.9028 0.6283 0.1584
553 1.2717 2.0148 0.7431 1.9173 0.6456 0.1510
554 1.2821 1.9012 0.6191 1.8485 0.5664 0.0930
555 1.2755 1.9086 0.6331 1.8556 0.5801 0.0914
336 1.2734 1.9092 0.6358 4.7730 1.8563 0.5829 0.0908
Sum 11.7773 4.1290 14.2563 11.3079 3.6596 0.7579
Ave. 1.9629 0.6882 Avg 1.8847 0.6099 0.1263
Ave. 0.1263
Mi 0.1263

 

 

175

 

Experimental Moisture Content “Me” Calculations at 20°C and different humidity
conditions.

Table M 1. Experimental Moisture Content “Me” Calculations at 20°C and different
humidity conditions.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Date : 1 1/12/2003 1 1/13/2003 1 1/14/2003
SNO. %RH PAN Salt PAN Wt Pan + Prod Pan+ prod
No. Name gm gm (RI)
Lithium
1 l 1 Licl-sal Chloride 1.2788 1.7795 1.7595 1.7602
2 532 1.2686 1.7936 1.7687 1.769
3 383 1.2782 1.7716 1.7541 1.7563
KC2H302-
4 21 sal Potassium 1.2744 1.7697 1.7582 1.7586
5 sa2 Acetate 1.2656 1.75 1.7395 1.7394
6 583 1.2743 1.7855 1.7745 1.7749
7 34 MgC 12-sa1 magnesium 1.2695 1.7348 1.7274 1.727
8 332 Chloride 1.2704 1.7497 1.7494 1.7437
9 sa3 1.272 1.7564 1.7434 1.7494
Mg(NO3)2-
10 55 sal magnesium 1.2698 1.7636 1.7662 1.7661
11 sa2 Nitrate 1.2856 1.7888 1.7914 1.7916
12 sa3 1.2743 1.764 1.7662 1.7663
13 63 NaNO3-sal Sodium Nitrate 1.2643 1.7562 1.7634 1.7645
14 sa-2 1.282 1.758 1.765 1.7658
15 sa-3 1.2757 1.7608 1.7673 1.7685
7200

16 % NaCl-sal Sodium 1.2637 1.7507 1.7782 1.7808
17 582 Chloride 1.2742 1.7777 1.8062 1.8093
18 sa3 1.2699 1.7807 1.8103 1.8113
19 83 KCl-sal Potassium 1 .2 763 1.7955 1.8431 1.8438
20 sa2 Chloride 1.2764 1.7563 1.7989 1.7992
21 sa3 1.2756 1.7873 1.8328 1.8335
22 96 K2SO4- sal Potassium 1.2689 1.772 1.913 1.9074
23 kclsa2 Sulphate 1.268 1.7625 1.9149 1.8944
24 kclsa3 1.2805 1.7752 1.9016 1.9008

 

 

 

 

 

 

 

 

 

 

176

 

(continued from Table M 1)

Date :

SNO. PAN
No.
Licl-sal
sa2
sa3

sa2
883

$32
sa3
O3
sa2
sa3

\OOOQONLIIDWN—

I—Ib—nlu—lI-I-
LAN—O

sa-2
sa-3

t—Dt—iI—l
OLA-b

saZ
sa3

——O—
000%

sa2
sa3

NNN
N—‘O

kclsaZ
kclsa3

rJN
Aw

KC2H302-sal

M -sa1

NaNO3-sal

7200% NaCl-sal

KCl-sal

KZSO4- sal

Lithium Chloride

Sodium Nitrate

 

177

(continued from table M 1.)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Date : 1 1/17/03 11/19/03 1 1/21/03 11/24/03
SNO. %RH PAN Salt
No. Name
Lithium
1 1 1 Licl-sal Chloride 1.7637 1.7643 1.7627 1.7632
2 sa2 ' 1.7702 1.7712 1.7703 1.7715
3 383 1.7583 1.7587 1.758 1.7588
4 21 KC2H302-sal Potassium 1.7592 1.7592 1.7599 1.758
5 sa2 Acetate 1.7403 1.7405 1.7393 1.7383
6 sa3 1.7764 1.7764 1.7757 1.7743
7 34 MgCl2-sal Magnesium 1.7271 1.7278 1.7278 1.727
8 $82 Chloride 1.7434 1.7435 1.7428 1.7427
9 583 1.7492 1.75 1.7492 1.7493
10 55 M g(NO3)2-sa 1 Magnesium 1.7664 1.7664 1.7664 1.7663
11 sa2 Nitrate 1.7917 1.7918 1.792 1.792
12 533 1.7666 1.7668 1.7668 1.7667
Sodium

13 63 NaNO3-sal Nitrate 1.7657 1.7662 1.7659 1.7661
14 sa-2 1.7666 1.7689 1.7675 1.7676
15 sa-3 1.7701 1.7705 1.7703 1.7705
16 7200% NaCl-sal Sodium 1.781 1.7825 1.7815 1.7823
17 sa2 Chloride 1.8094 1.81 1.8098 1.8106
18 583 1.8114 1.8116 1.811 1.8127
19 83 KCl-sal Potassium 1.842 1.8412 1.8411 1.841
20 sa2 Chloride 1.7985 1.7981 1.7985 1.7986
21 sa3 1.8327 1.8321 1.832 1.8321
22 96 K2SO4- sal Potassium 1.9256 1.917 1.9216 1.8805
23 kclsa2 Sulphate 1.9133 1.903 1.9076 1.8681
24 kclsa3 1.9242 1.9142 1.9188 1.8786

 

 

 

 

 

 

 

 

 

 

178

 

(continued from table M1)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Date : 1 1/27/2003 1 1/30/2003 12/4/2003
SNO. %RH PAN Salt
No. Name

1 11 Licl-sal Lithium Chloride 1.765 1.7682 1.7677
2 sa2 1.7753 1.7784 1.7759
3 383 1.7645 1.7671 1.7639
4 21 KC2H302-sal Potassium 1.7589 1.7585 1.7576
5 sa2 Acetate 1.7401 1.7396 1.739
6 sa3 1.7784 1.7758 1.7749
7 34 M gClZ-sal magnesium 1.7273 1.7288 1.7277
8 $32 Chloride 1.7434 1.7438 1.7421
9 583 1 .7499 1.7503 1.7494
10 55 M gQ‘l O3)2-sal magnesium 1.7666 1.7666 1.7665
1 l sa2 Nitrate 1.7922 1.7923 1.7916
12 583 1.7668 1.7678 1.7666
13 63 NaNO3—sal Sodium Nitrate 1.7662 1.7667 1.7671
14 sa-2 1.7677 1.7685 1.7689
15 sa-3 1.7708 1.772 1.7725
16 7200% NaCl-sal Sodium 1.7834 1.7839 1.7828
17 sa2 Chloride 1.8109 1.8115 1.8097
18 sa3 1.8135 1.8151 1.8132
19 83 KC l-sa 1 Potassium 1.8431 1.843 1.844
20 882 Chloride 1.8007 1.801 1.8022
21 sa3 1.8333 1.8335 1.8377
22 96 K2SO4- sal Potassium 1.9028 1.9017 1.8562
23 kclsa2 Sulphate 1.8895 1.8887 1.8876
24 kclsa3 1.9036 1.9025 1.8612

 

 

 

 

 

 

 

179

 

(Continued from table M 1)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Date : 12/8/2003 12/15/2003
SNO. %RH PAN Salt
No. Name
1 1 1 Licl-sal Lithium Chloride 1.736 1.7659
2 532 1.7737 1.7794
3 sa3 1.7612 1.7672
4 21 KC2H302-sal Potassium 1.758 1.7573
5 $82 Acetate 1.7392 1.738
6 sa3 1.7749 1.7738
7 34 MgClZ-sal magnesium 1.7273 1.7276
8 582 Chloride 1.7422 1.7425
9 sa3 1.7494 1.749
10 55 M g(NO3)2-sa1 magnesium 1.7669 1.7673
1 1 sa2 Nitrate 1.7916 1.7922
12 583 1.7665 1.7671
13 63 NaNO3-sal Sodium Nitrate 1.7665 1.7663
14 sa-2 1.768 1.7682
15 sa-3 1.7715 1.7713
16 7200% NaCl-sal Sodium 1.7819 1.7821
17 532 Chloride 1.809 1.811
18 sa3 1.8126 1.8124
19 83 KC l-sa 1 Potassium 1.8421 1.8464
20 sa2 Chloride 1.8009 1.8054
21 sa3 1.835 1.8403
22 96 KZSO4- 53] Potassium 1.9643 2.0065
23 kclsa2 Sulphate 1.9597 1.9954
24 kclsa3 1.9075 1.989
Fungus Fungus

 

180

 

(continued from Table M 1)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

%RH PAN Salt
No. Name Ange Wi Avg Wi %RH Me Aw w/Me
Lithium
11 LicI-sa1 Chloride 0.5007 0 0 0 0
sa2 0.525
sa3 0.4943 0.4934 0.5064 11 0.0995 0.11001.1051
KC2H302-
21 sa1 Potassium 0.4953
532 Acetate 0.4844
sa3 0.4849 0.5112 0.4970 21 0.0990 0210021206
34 MgCl2-sa1 magnesium 0.4653
332 Chloride 0.4793
sa3 0.4691 0.4844 0.4763 34 0.109103400311591
Mg(NO3)2- 1
55 sa1 magnesium 0.4938
sa2 Nitrate 0.5032 |
533 0.4990 0.4897 0.4956 55 0.1340 05500410361
63 NaNOB-sa1 Sodium Nitrate 0.4919
sa-2 0.476
sa-3 0.4946 0.4851 0.4843 63 0.1502 0630041951
7200
% NaCl-sa1 Sodium 0.487
s32 Chloride 0.5035
833 0.5326 0.5108 0.5004 0.72 0.1986 0720036250
83 KCl-sa1 Potassium 0.5192
332 Chloride 0.4799
633 0.5546 0.5117 0.5036 83 02404 0830034531
96 K2804-sa1 Potassium 0.5031
kcI-sa2 Sulphate 0.4945
kcl-sa3 0.5959 0.4947 0.4974 96 0.3492 0.9600 .7493

 

 

GAB model constants and T ,C Wm and K Values:

(X
B
Y
T
C
Wm

K

= -11.089
= 13.525
= -0.1353

-117.92

= 0.9917,-118.9143

-0.0752, 0.0752
99.1363

181

RMS calculations.

Table M 2. RMS calculation for GAB model at 20°C and different %RH conditions

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Aw CkAw (1-kAw).. M (Gab) M (Exp)
0 0 0 0

0.11 10.8141 -9.0042 0.0903 0.0995 0.0925 0.0086
0.21 20.6450 -16.3779 0.0948 0.0990 0.0427 0.0018
0.34 33.4253 -23.5130 0.1069 0.1091 0.0206 0.0004
0.55 54.0703 -29. 1872 0.1393 0.1340 -0.0392 0.0015
0.63 61.9350 -29.4473 0.1581 0.1502 -0.0530 0.0028
0.72 70.7829 -28.4860 0.1868 0.1986 0.0595 0.0035
0.83 81.5970 -25.5080 0.2405 0.2404 -0.0006 0.0000
0.96 94.3772 -19.4315 0.3651 0.3490 -0.0463 0.0021
0.0026
RMS 5.1025

 

182

 

Experimental Moisture Content “Me” Calculations at 25°C and different humidity

conditions.

Table M 3. Experimental Moisture Content “Me” Calculations at 25°C and different
humidity conditions.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Date
: 7/7/2003 7/7/2003 7/8/2003
SNO. %RH PAN Salt PAN Wt Pan + Prod Pan+ prod
No. Name gm gm (R1)

1 15 Licl-sal Lithium 1.2748 2.0449 1.9968 1.995
2 sa2 Chloride 1.2737 2.0261 1.9825 1.9786
3 583 1.2726 2.0386 1.9906 1.9883
4 23 1((C2 H302)-sa1 Potassium 1.2708 2.0291 1.9971 1.9966
5 sa2 Accetate 1.2684 2.0295 1.993 1.991
6 sa3 1.2748 2.1493 2.1104 2.1076
7 35 MgCl-sal Magnesium 1.2732 2.02 1.9889 1.9885
8 $82 Chroride 1.2739 2.026 1.9931 1.9922
9 sa3 1.275 2.0126 1.9829 1.982
10 51 Mg(NO3)2-sa1 Magnesium 1.2666 2.0123 2.0069 2.0057
1 1 582 Chloride 1.2785 2.004 1.9979 1.9968
12 sa3 1.2834 2.0199 2.0124 2.0115
13 63 NaNoZ-sal Sodium 1.2719 2.0168 2.0166 2.0161
14 $82 Nitride 1.2753 2.0207 2.02 2.0193
15 sa3 1.2725 2.0313 2.0308 2.0305
16 73 Naclsal Sodium 1.2732 2.0371 2.0728 2.0744
17 Naclsa2 C hroride 1.2746 2.0016 2.0295 2.0309
18 NaClsa3 1.2737 2.016 2.0455 2.0469
19 84 kc] -sa1 Potassium 1.2755 2.0182 2.0928 2.0912
20 kcl-saZ Chloride 1.2717 2.0024 2.0769 2.081
21 kcl-sa3 1.2797 2.01 14 2.0886 2.0902

 

 

 

 

 

 

183

 

(continued from table M3)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Date : 7/9/2003 7/10/2003 7/1 1/2003
SNO. %RH PAN Salt
No. Name

1 15 Licl-sa 1 Lithium 1.9944 1.9946 1.9946
2 sa2 Chloride 1.9782 1.9784 1.9773
3 sa3 1.9888 1.9891 1.9873
4 23 K(C2H302)-sa1 Potassium 1.9949 1 .9975 1.9931
5 sa2 Accetate 1.9906 1.992 1.9896
6 sa3 . 2.1073 2.1114 2.1057
7 35 MgC 1-sa1 Magnesium 1.9875 1.9877 1.9863
8 $82 Chroride 1 .9904 1 .9907 1.9802
9 sa3 1.9812 1.9816 1.9801
10 5 1 Mg(NO3)2-sa 1 Magnesium 2.0047 2.0049 2.0032
1 1 $82 Chloride 1.9966 1.9966 1 .9949
12 sa3 2.011 2.011 2.0094
13 63 NaNoZ-sal Sodium 2.015 2.0152 2.0146
14 sa2 Nitride 2.0186 2.0184 2.0178
15 sa3 2.0297 2.0073 2.007
16 73 Naclsal Sodium 2.073 2.0733 2.0705
17 NaclsaZ Chroride 2.0306 2.0297 2.0282
18 NaClsa3 2.0462 2.047 2.0453
19 84 kc] -sa1 Potassium 2.088 2.0802 2.0802
20 kcl—sa2 Chloride 2.0762 2.0656 2.066
21 kcl-sa3 2.0822 2.0754 2.0721

 

 

 

 

 

 

 

184

 

(continued from Table M3)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

7/ 1 2/03/ 7/1 3/03/ 7/1 2/03/ 7/14/03/
SNO. %RH PAN Salt Pan + Prod Pan + Prod Pan + Prod Pan + Prod
No. Name m (R2) Fm (R2) Em (R2) (m (R2)

1 15 Licl-sal Lithium 1.9929 0.7181 1.993 0.7182
2 sa2 Chloride 1 .9761 0.7024 1.9765 0.7028
3 sa3 1.9863 0.7137 1.9871 0.7145
4 23 K(C2H302)-sa1 Potassium 1.9927 0.7219 1.9929 0.7221
5 sa2 Accctate 1 .9887 0.7203 1 .9898 0.7214
6 583 2.1047 0.8299 2.105 0.8302
7 35 MgCl-sal Magnesium 1.9869 0.7137 1.9886 0.7154
8 sa2 Chroride 1 .9898 0.7159 1 .9906 0.7167
9 sa3 1 .9805 0.7055 1.9819 0.7069
10 51 Mg(NO3)2-sa1 Magnesium 2.004 0.7372 2.0038 2.0038
1 1 sa2 Chloride 1.9959 0.717 1.9955 1.9956
12 sa3 2.0105 0.7266 2.01 2.0101
13 63% NaNoZ-sal Sodium 2.0156 0.7437 2.0161 0.7442
14 sa2 Nitride 2.0189 0.7436 2.0185 0.7432
15 583 2.0079 0.7354 2.0083 0.7358
16 73 Naclsal Sodium 2.0725 0.7993 2.0726 0.7994
17 Naclsa2 Chroride 2.0298 0.7552 2.0298 0.7552
18 NaClsa3 2.0726 0.7989 2.0472 0.7735
19 84 kc] -sal Potassium 2.0882 0.8127 2.0854 2.0902
20 kcl-sa2 Chloride 2.0694 0.7977 2.075 2.0759
21 kcl-sa3 2.078 0.7983 2.0792 2.0804

 

185

 

(continued from table M3)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

7/15/2003 7/17/2003
SNO. %RH PAN Salt Pan + Prod
No. Name

1 15 Licl-sal Lithium 1.9923 1.9929
2 sa2 Chloride 1.766 1.9756
3 sa3 1.986 1.986
4 23 1((C 2H302)-sa1 Potassium 1.9932 1.9932
5 sa2 Accetate 1.9892 1.9892
6 sa3 2.105 2.1047
7 35 MgCl-sal Magnesium 1.967 1.9866
8 $32 Chroride 1.991 1.9898
9 583 1.981 1 1.9806
10 5 1 Mg(NO3)2-sa 1 Magnesium 2.004 2.004
1 1 sa2 Chloride 1.9957 1.9956
12 sa3 2.01 2.0104
13 63% NaNoZ-sal Sodium 2.0153 2.0152
14 sa2 Nitride 2.0184 2.0182
15 sa3 2.0081 2.0079
16 73 Naclsal Sodium 2.0723 2.0722
17 NaclsaZ Chroride 2.0292 2.029
18 NaClsa3 2.046 2.0461
19 84 kcl -sal Potassium 2.0876 2.1044
20 kcl-sa2 Chloride 2.0771 2.077
21 kcl-sa3 2.0826 2.0825

 

186

 

(continued from M3)

 

%

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

RH PAN Salt SD 8.0 Ave. Ave. 8.0
No. Name We We (We) (We) Wi Wi Wi (wi)
15 LicI-sa1 Lithium 0.718 0.770
sa2 Chloride 0.701 0.752
sa3 0.713 0.711 0.0083 0.0083 0.762 0.766 0.7628 0.0093
K(CZH302)-
23 sa1 Potassium 0.722 0.758
sa2 Accetate 0.720 0.761
sa3 0.829 0.757 0.0625 0.0625 0.797 0.874 0.7980 0.0663
35 MgCl-sa1 Mamesium 0.713 0.746
sa2 Chroride 0.715 0.752
sa3 0.705 0.711 0.005 0.0054 0.745 0.737 0.7455 0.0073
51 Mg(N03)2 Magesium 0.737 0.746
582 Chloride 0.717 0.725
sa3 0.727 0.727 0.010 0.0102 0.745 0.736 0.7450 0.0103
63 NaNoZ-sa1 Sodium 0.743 0.744
882 Nitride 0.742 0.745
sa3 0.735 0.740 0.004 0.0045 0.749 0.758 0.7497 0.0079
73 Naclsa1 Sodium 0.79 0.763
Naclsa2 Chroride 0.754 0.727
NaClsa3 0.772 0.775 0.022 0.0224 0.744 0.742 0.7444 0.0185
84 kcl-sa1 Potassium 0.828 0.742
kcl-$32 Chloride 0.805 0.730
kcl-saa 0.802 0.812 0.014 0.0144 0.735 0.731 0.7350 0.0067

 

187

 

(continued from M3)

 

%RH

Me (separate) Me Aw

Aw/Me

 

0

0.0502 0 0

0

 

0.0507

 

15

0.0490 0.0499665 0.15

3.00200912

 

0.0730

 

0.0667

 

23

0.0689 0.0694651 0.23

3.31101463

 

0.0759

 

0.0721

 

35

0.0774 0.0751343 0.35

465832494

 

0.1129

 

0.1128

 

51

0.1115 0.0993394 0.51

5.13391716

 

0.1239

 

0.1225

 

63

0.0916 0.1125286 0.63

559857659

 

0.1781

 

0.1687

 

73

0.1720 0.1730022 0.73

4.21959923

 

0.2570

 

0.2413

 

 

84

 

 

 

0.2357 0.2447477 0.84

 

 

3.43210614

 

GAB model constants and T ,C Wm and K Values:

-18.971
19.935
0.0619

342.417

341.4136 , 1.0029
0.0499, -0.0499
0.9488

188

FF

RMS Calculations

Table M 4. RMS calculation for GAB model at 25°C and different %RH conditions

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Aw CkAw (1-kAw).. MQGabJ M(Exp)
0 0 0

0.15 48.5924 42.4120 0.0571 0.0501 -0.1401 0.0196
0.23 74.5084 58.8592 0.0631 0.0695 0.0917 0.0084
0.35 113.3823 76.1745 0.0742 0.0760 0.0233 0.0005
0.51 165.2142 85.5314 0.0963 0.0993 0.0299 0.0009
0.63 204.0881 82.2514 0.1237 0.1125 —0.0999 0.0100
0.73 236.4831 72.7755 0.1620 0.1730 0.0633 0.0040
0.84 272.1175 55.2724 0.2455 0.2447 -0.0033 0.0000
0.0062
RMS 7.8810

 

189

 

Experimental Moisture Content “Me” Calculations at 30°C and different humidity
conditions.

Table M 5. Experimental Moisture Content “Me” Calculations at 30°C and different
humidity conditions.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Date: 10/22/2003 10/23/2003 10/24/2003
SNO. %RH PAN Chemical PAN Wt Pan + Prod Pan+ prod Pan+ prod
No. Name L g (Q (9L
1 1 1 Licl-sa1 Lithium 1 .2742 1 .7724 1.7587 1.7576
2 sa2 Chloride 1 .2823 1.7839 1 .7696 1.769
3 sa3 1 .2746 1 .8024 1 .7882 1.7865
4 45 K2003-sa1 Potassium 1 .271 1 .7585 1 .7559 1 .7552
5 sa2 Carbonate 1 .2761 1 .7894 1 .7863 1 .786
6 333 1.2691 1.7469 1.7441 1.7443
7 56 MgZNo3-sa1 Magnesium 1.2743 1.7207 1.7231 1.7238
8 $32 Nitrate 1 .2813 1.7587 1.761 1.7621
9 sa3 1 .2633 1.7577 1.7608 1.7619
10 77 Nacl-sa1 Sodium 1 .2639 1 .7227 1.7395 1.74
1 1 sa2 Chloride 1 .2664 1 .7683 1 .7882 1.7897
12 $33 1 .2756 1 .7563 1.7746 1 .7763
13 8400% Kcl-sa1 Potassium 1.2692 1.7522 1.7822 1.7856
14 sa2 Chroride 1.273 1 .7482 1.7773 1 .7833
15 sa3 1 .2827 1 .7695 ‘l .798 1.8024
16 90 K2No3-sa1 Potassium 1 .2799 1 .7678 1.8237 1.8279
17 $32 Nitrate 1.2754 1.7563 1.8109 1.8147
18 333 1.2728 1.777 1.8321 1.8382
19 96 K2so4- sa1 Potassium 1.277 1.7766 1.8346 1.853
kclsaZ Sulphate 1.2755 1.7724 1.8273 1.8516
kclsa3 1 .2809 1 .7942 1 .8546 1 .8744

 

190

 

(continued from table M5)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Date : 10/2 5/2003 10/27/2003 10/28/2003 10/29/2003
SNO. °/o RH PAN Chemical
No. Name
1 1 1 Licl-sa1 Lithium 1 .7577 mfd
2 sa2 Chloride 1 .7678 1 .7595 1 .7558 1.7564
3 sa3 1 .7864 1 .7857 1 .7809 1 .7823
4 45 K2C03-sa1 Potassium 1 .755 1 .7551 1 .7539 1.7547
5 $32 Carbonate 1 .785 1 .7853 1.7849 1 .7852
6 533 1.7437 1.7438 1.7433 1.7432
M92N03-
7 56 sa1 Magnesium 1.723 1 .7225 1.724 1 .723
8 sa2 Nitrate 1.7613 1 .7628 1 .7613 1 .7608
9 sa3 1.7605 1.7625 1.7619 1.7606
10 77 NaCI-sa1 Sodium 1.7404 1.742 1.7423 1.7419
1 1 $32 Chloride 1 .7892 1.791 1.7909 1.7906
12 sa3 1 .7772 1 .7778 1.7773 1.7769
13 8400 KCl-sa1 Potassium 1.7864 1.7902 1 .7904 1 .7924
14 $32 Chroride 1.7845 1.7875 1.785 1.788
15 333 1.8037 1.8056 1.806 1.808
16 90 K2N03-sa1 Potassium 1.8314 1.852 1.844 1.8494
17 sa2 Nitrate 1 .8189 1 .8393 1.8306 1.8361
18 533 1.8416 1.8573 1.8535 1.8561
19 96 K2804- sa1 Potassium 1.8564 1.8643 1.8576 1.8623
KCIsaZ Sulphate 1 .855 1 .8624 1.8597 1.8593
KClsa3 1 .8812 1 .8832 1.8806 1.8839

 

 

 

 

 

 

 

 

 

191

(continued from table M5)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Date : 10/30/2003 11/2/2003 11/3/2003 11/5/2003
SNO. %RH PAN Chemical
No. Name

1 11 Licl-sa1 Lithium
2 $32 Chloride 1.7604 1.7915 1.7627 1.7532
3 533 1.787 1.7972 1.788 1.788
4 45 K2C03-sa1 Potassium 1 .7554 1 .7547 1.7538 1.7536
5 sa2 Carbonate 1.7858 1 .7854 1.7852 1 .7845
6 sa3 1.7439 1.7438 1.7436 1.7436
7 56 Mflo3-sa1 Magnesium 1.7233 1.7224 1.728 1.726
8 sa2 Nitrate 1 .7623 1 .7609 1.7613 1 .761
9 sa3 1.7614 1.7605 1.7598 1.7603
10 77 Nacl-sa1 Sodium 1.7438 1.743 1.7428 1.7424
11 sa2 Chloride 1.7918 1.7921 1.7921 1.7923
12 sa3 1.7798 1 .7784 1.7782 1.7782
13 8400% Kcl-sa1 Potassium 1 .7915 1 .7932 1 .7958 1.7972
14 sa2 Chroride 1.788 1 .7888 1.7891 1.7978
15 sa3 1.808 1.81 1.811 1.8099
16 90 K2No3-sa1 Potassium 1.8506 1 .8615 1.8661 1.86
17 sa2 Nitrate 1.8391 1 .8473 1.8535 1.8474
18 sa3 1.8607 1.8669 1.8754 1.8669
19 96 K2304- sa1 Potassium 1.864 1.8869 1.8848 1.8836

kclsa2 Sulphate 1 .8629 1 .8776 1 .8772 1 .8764

kclsa3 1.8853 1.9043 1.9035 1.9014

 

 

 

 

 

 

 

 

192

 

 

(continued from table M5)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Date : 11/7/2003 1 1/9/2003 11/17/2003
SNO. %RH PAN Chemical
No. Name
1 1 1 Licl-sal Lithium
2 sa2 Chloride 1.753 1.75 1.75
3 sa3 1.7874 1.7871 1.7871
4 45 K2co3-sal Potassium 1.7536 1.736 1.735
5 sa2 Carbonate 1.785 1.7851 1.7851
6 sa3 1 .7442 1 .7441 1.744
7 56 Mg2No3-sal Magnesium 1.7221 1.722 1.7222
8 sa2 Nitrate 1 .7602 1 .7602 1.7603
9 sa3 1.7602 1.7602 1.7604
10 77 Nacl-sal Sodium 1.7426 1.7425 1.743
1 1 $32 Chloride 1.792 1.7922 1.7923
12 533 1.7782 1.7782 1.7792
13 8400% Kcl-sal Potassium 1.7935 1.7936 1.794
14 sa2 Chroride md
15 sa3 1.8088 1.8091 1.81
16 90 K2No3-sal Potassium 1.8606 1.8595 1.8661
17 sa2 Nitrate 1.8472 1.8465 1.8535
18 333 1.8683 1.8683 1.8754
19 96 K2504- sa1 Potassium 1.8816 1.8837 1.9094
kclsa2 Sulphate 1.8774 1.8809 1.9039
kclsa3 1.903 1.9075 1.9333

 

193

 

 

(continued from table M5)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SNO. %RH PAN Chemical
No. Name We Avg We Wi Avg Wi
1 11 Licl-sa1 Lithium 0.4982
2 sa2 Chloride 0.4677 0.5016
3 sa3 . 0.5125 0.4901 0.5278 0.5092
4 45 K2C03-sa1 Potassium 0.4640 0.4875
5 $32 Carbonate 0.5090 0.5133
6 533 0.4749 0.4826 0.4778 0.4929
7 56 IM92N03-3a1 Magnesium 0.4479 0.4464
8 $32 Nitrate 0.4790 0.4774
9 sa3 0.4971 0.4747 0.4944 0.4727
10 77 Nacl-sa1 Sodium 0.4791 0.4588
11 $32 Chloride 0.5259 0.5019
12 sa3 0.5036 0.5029 0.4807 0.4805
13 8400°/o Kcl-sa1 Potassium 0.5248 0.483
14 sa2 Chroride 0.4752
15 sa3 0.5273 0.5261 0.4868 0.4817
16 90 K2No3-sa1 Potassium 0.5862 0.4879
17 sa2 Nitrate 0.5781 0.4809
18 sa3 0.6026 0.5890 0.5042 0.4910
19 96 K2$o4- sa1 Potassium 0.6324 0.4996
kclsa2 Sulphate 0.6284 0.4969
kclsa3 0.6524 0.6377 0.5133 0.5033

 

194

 

(continued from table M5)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SNO. % RH PAN Chemical
No. Name °/o RH Me Aw Aw/Me
1 11 Licl-sa1 Lithium 0 0 0 0
2 sa2 Chloride
3 $33 11.0000 0.0841 0.11 1.3087
4 45 K2co3-sa1 Potassium
5 sa2 Carbonate
6 $33 43.0000 0.1029 0.43 4.1782
7 56 IMgNo3-sa1 Magnesium
8 sa2 Nitrate
9 $33 53.0000 0.1309 0.53 4.0487
10 77 Nacl-sa1 Sodium
1 1 $32 Chloride
12 $33 75.0000 0.1788 0.75 4.1944
13 8400% Kcl-sa1 Potassium
14 sa2 Chroride
15 $33 83.0000 0.2301 0.83 3.6074
16 90 K2N03-sa1 Potassium
17 $32 Nitrate
18 sa3 90.0000 0.3510 0.9 2.5639
19 96 K2504- sa1 Potassium
kclsaZ Sulphate
kclsa3 96.0000 0.4272 0.96 2.2470

 

195

 

GAB model constants and T ,C Wm and K Values for GAB model at 30C:

0t = -13.726

B = 15.643

Y = -0.1 123

T -154.7509

C = 0.9936
Wm = 00647

K 138.4135
RMS Calculations:

Table M 6. RMS calucaltions at 30°C and different %RH conditions

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Aw CkAw (1-kAw).. M (Gab) M (Exp)
0 0 0

0.11 15.1283 —12.8437 0.0763 0.0841 0.0932 0.0087
0.45 61.8887 -36.9326 0.1085 0.1029 -0.0544 0.0030
0.56 77.0170 -38.6759 0.1289 0.1309 0.0151 0.0002
0.77 105.8984 -33.7904 0.2029 0.1765 -0.l499 0.0225
0.84 115.5256 -29.7663 0.2513 0.2301 -0.0922 0.0085
0.9 123.7774 -25.3637 0.3160 0.3510 0.0999 0.0100
0.96 132.0292 -20.0810 0.4257 0.4272 0.0036 0.0000
0.0075
RMS 8.6861

 

196

 

APPENDIX D

THERMAL INSULATION PROPERTIES CALCULATIONS OF
GREEN CELL® FOAM.

Table T 1. (R-Value ) calculation of GCF and EPS coolers at 50%RH and 25°C

Condition 2 50%RH and
25°C

Preconditioning time = 145 minutes=2.4l6
hrs

Inside
temperaturele =32°F
Outside
temperature=T2=77°F
Temperature difference:
45° F

Latent heat of ice: 11b of ice at 32F absorb
144btu(36.3Kcal)

Area of cooler
EPS=2(LD+WD=LW)=4.421ft2

 

 

 

 

 

 

 

 

Length Width Height
L w D 2LD 2WD 2LW Area Area
in in in 1.12 ft2
11.875 10 9.125 216.71875 182.5 237.5 636.719 4.4217

 

 

 

 

 

 

Area of cooler Green Cell
C0016F=2(LD+WD=LW)=4.37ft2

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Length Width Height I
L W D 2LD 2WD 2LW Area I Area
in in in in2 ft2
11.687 10 9.125 213.28775 182.5 233.74 629.528 4.3717
EPS Coolers
wt. Of
Trial wt of bucket wt. Of water wt. Of water water Time Melt Rate R- value
No. and ice collected
lbs ml kg lbs hr lbs/hr hr.ft2.F/Btu
7 2350 2.35 5.17 48 0.1077 12.8250
2 7 1061 1.061 2.3342 24 0.0973 14.2019

 

 

 

 

 

 

 

 

 

 

197

Green Cell cooler

 

 

 

 

 

 

 

 

 

 

 

 

 

trial no. wt of bucket wt. Of water wt. Of water wt. Of water Time Melt Rate R- value I
and ice collected I
lbs ml kg lbs hr lbs/hr hr.ft2.F/Btu

1 7 2500 2.5 5.5 48 0.1 146 11.9182

2 7 l 125 1.125 2.475 24 0.1031 13.2424

 

 

Table T 2. (R-Value ) calculation. of GCF and EPS coolers at 80%RH and 30°C

Condition = 80%RH and 30°C(86F)

Preconditioning time = 145 minutes=2.4l6 hrs

Inside temperature=Tl=32°F

Outside temperature=T2=86°F

Temperature difference: 54 °F

Latent heat of ice: 11b of ice at 32°F absorb l44btu(36.3Kcal)

Area of cooler EPS=2(LD+WD=LW)=4.421f12

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Length Width Height
L W D 2LD 2WD 2LW Area Area
in in in in2 f8
1 1.875 10 9.125 216.71875 182.5 237.5 636.719 4.4217
Area of cooler Green Cell coole1=2(LD+WD=LW)=4.37ft2
Length Width Height
L W D 2LD 2WD 2LW Area Area
in in in in2 ft2
1 1.687 10 9.125 213.2878 182.5 233.74 629.528 4.3717
EPS Coolers
trial
no. wt of bucket wt. Of water wt. Of water wt. Of water Time Melt Rate R value
and ice collected
lbs ml kg lbs hr lbs/hr hr.ft2.F/Btu
1 7 1950 1.95 4.29 26 0.165 10.0455

 

 

 

 

 

 

 

 

 

 

198

Green Cell

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

cooler
Trial
no. wt of bucket wt. Of water wt. Of water wt. Of water Time Melt Rate R value
and ice collected
lbs ml kg lbs hr lbs/hr hr.ft2.F/Btu
l 7 2400 2.4 5.28 26 0.2031 7.8036
Density Calculations:
Table T 3. Density calculation of l-inchand 2-inch Green Cell® foam
1 " thickness Green Cell Foam
s.no Weight Weight Volume Density
(g) (lb) w* L * D (lb/r13)
(in’)
1 20.78 0.04577 25.2123 3.1368
2 30.98 0.06823 37.6068 3.1349
3 15.39 0.03389 19.9149 2.9405
Ave. 3.07073
2 " thickness Green Cell Foam
Weight Weight Volume Density
(g) (lb) w* L * D (Ib/ft3)
in3
1 123.78 0.2726 141.504 3.3288
2 135.15 0.2976 149.216 3.4463
135.32 0.298 156.224 3.2961
Ave. 3.3571

 

 

 

 

 

 

Average value of 2-inch thick foam = 3.351h/ft3

Average value of 1-inch thick foam = 3.071b/ft3

Average value of l-inch thick and 2- inch thick foam = 3.211h/ft3

199

 

 

 

APPENDIX E
PREPARATION OF SALT SOLUTION ASTM STD. E 104
Salt Solutions.

Materials
. Biodegradable Starch based foam (Green Cell®)

' 80 Aluminum dishes

' 3 sets of HDPE buckets, every set contains 8 HDPE buckets, maintained at
different relative humidity (%RH) conditions and three different temperatures
(20°C, 25°Cand 30°C).

' 8 aqueous salt solutions to create different (% RH) condition in HDPE buckets.

Reagents
Total ten chemicals were used to create different relative humidity conditions like
Lithium Chloride, Potassium Acetate, Magnesium Chloride, Potassium Carbonate,
Magnesium Nitrate, Sodium Nitrite, Sodium Chloride, Potassium Chloride, Barium
Chloride, Potassium Sulfate.
Reagents grade chemicals were used to prepare all standard salt solutions according to
ASTM standard E104 [2].
Saturated salt solutions were prepared by using hydrated reagents. Hydrated reagents are
often preferred to amorphous forms for their solvating characteristics. Equilibrium
Relative humidity values (standards and actual) for selected saturated
Additional reagents and Equipments

I Demilitarized water:

I Analytical Balance (sensitivity is i0.0001 grams)

200

I Vacuum Oven (SO-75°C and 22-25 inches Hg)
I Hygrometer

I 24 Pyrex container

I Hot Plate

I Magnetic stirrer.

Preparation Method

2.1.3-a Preparation of salt solution:

A quantity of the selected salt was weighed into the Pyrex container and water was added
in about 2-ml increments. Each container was heated on the hot plate to maintain a
constant temperature; one magnetic stirrer was inserted into the container to provide
mixing, until equilibrium was reached. [2]

A saturated salt solution occurs when any excess quantity of undisclosed solute is
present. After preparing the salt solution, the containers were placed inside the HDPE
buckets and tightly closed with a lid .One hour was given to maintain the temperature
stabilization before checking the first reading of humidity by Hygrometer.

The stability of the humidity conditions was checked periodically over a three weeks
period.

Table S-l shows the Equilibrium Relative humidity values (standards and actual) for
selected saturated solutions.

The stability of the humidity conditions was checked periodically over a three weeks

period.

201

Table S-l represents the equilibrium Relative humidity values (standards and actual) for
selected saturated solutions.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Salt Name Formula Temperature (°C )
20°C 25°C 30°C
E 104 Actual E 104 Actual E 104 Act
ual
Lithium LiCl 11.3 11 11.3 15 11.3 11
Chloride
Potassium KC3H3OZ 23.1 21 22.5 23 21.6
Acetate
Magnesium MgClz 33.1 34 32.8 35 32.4
Chloride
Potassium K2CO3 43.2 43.2 43.2 45
Carbonate
Magnesium Mg(N03)2 54.4 55 52.9 51 51.4 56
Nitrate
Sodium 63 63
Nitrite
Sodium NaCl 75.5 72 75.3 73 75.1 77
Chloride
Potassium KC 1 85.1 83 84.3 84 84.3 84
Chloride
Barium BaC 12 91 90 89 90
Chloride
Potassium K2804 97.3 96 97.3 97.0 96
Sulphate

 

 

 

 

 

 

 

 

202

 

5-a

8.

REFERENCES

. An introduction to plastics. Plastic Manufacturing Methods.

www.calibre.co.nz~’p1asticc.htm. Access date July 4, 2005.

American Standard Test Methods. 2002. Standard Practice for maintaining
Constant Relative Humidity by Means of Aqueous Solutions. Annual Book of
ASTM Standards: E 104-85(Reapproved 1996).11:01

American Standard Test Methods. 2002. Standard Test Methods for Dynamic
Shock Cushioning of Packaging Materials. Annual Book of ASTM Standards. D
— 1596.15.09, Philadelphia, PA.

Association of Analytical Chemists (AOAC). 2000.0fficial Method 934.06,first
action 1934,

Arif.Samina,Harte.Bruce,Burgess.Gary and Narayan.Ramayn. Performance
Properties of Green Cell® Foam. 2003. Proceedings of 4th Biomechanics
Conference. East Lansing Michigan, USA July 21-25,2003.

Arif . Samina,Burgess. Gary, Narayan. Ramani and Harte. Bruce. Evaluation of
a Biodegradable Foam for Packaging Applications.2005. Proceedings of Annual
[F T Conference. Louisiana, USA, Juy 15-20, 2005.

Arif . Samina,Burgess. Gary, Narayan. Ramani and Harte. Bruce. Evaluation

of a Biodegradable Foam for Protective Packaging Applications.2007.
Packaging Technology and Science.published on line Feb 07,2007.John Wiley &
Sons,Ltd

Biodegradable plastics. http://www.bch.msu.edu/~sinas./biodeghtml. Access date
MaylS, 2004.

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