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This is to certify that the
thesis entitled

A Performance Comparison of Thermal Insulated
Packaging for Single Parcel Shipments

presented by

Prasad Mulukutla

has been accepted towards fulfillment
of the requirements for the

MS degree in Packaging

   
 

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6/01 c'JCIRC/DmeDuepGS-sz

 

 

A Performance Comparison of Thermal Insulated Packaging
For Single Parcel Shipments

By

Prasad Mulukutla

A THESIS

Submitted to
Michigan State University
In Partial fulﬁllment of the requirements
for the degree of

MASTER OF SCIENCE
In
PACKAGING

College of Agricultural and Natural Resources

2003

ABSTRACT
A Performance Comparison Of Thermal Insulated Packaging
For Single Parcel Shipments
By

Prasad.V.Mulukutla

Insulated packaging is an important area of study in packaging. A large number of
temperature sensitive perishable products (meat, seafood, ﬂowers, pharmaceuticals, etc)
are shipped in the single parcel shipping environment of carriers such as Fedex, USPS,
and UPS. The purpose of this research was to investigate the insulation effectiveness of
various commercially available and newly developed insulated packages. The packages
studied included single wall corrugated containers, Box-in-Box packaging systems with
an air gap, Thermal-Cor® boxes, and corrugated containers with (expanded poly styrene)
EPS foam panels. Ice-melt tests were conducted both at room temperature (74°F) and at
104°F. The air temperature variation with respect to time inside the package was also
measured at room temperature (74°F) and at 104°F by placing dry ice and gel ice inside
the package. Temperature measurement recorders were used to record the temperature
change inside the package over time. The packages were also subjected to pre-shipment
tests in accordance with the International Safe Transit Association, Test Procedure 1A.
Based on the results of this study, the melt rates of the box-in-box packages were found
to be less compared to those of single packages. Also the time-temperature analysis
inside the package showed that the foil laminated Thermal-Cor® boxes were found to
slow the heat transfer process as compared with the other packaging systems tested like

corrugated boxes with EPS foam panels.

ACKNOWLEDGEMENTS

I would like to express my sincerest thanks to my advisor, Professor S Paul Singh for his
support, guidance, and leadership throughout my graduate education. In addition, I would
like to thank Professor Gary Burgess and Dr. Brian Feeny for serving on my Master’s
Defense committee.

I would like to thank Dr. J agjit Singh who helped me through out my research
work with valuable suggestions and also assisted me in performing Thermal Analysis
Experiments.

I would like to thank the faculty and the graduate students of School of Packaging
for their support through out my graduate studies.

Last, but not the least, I deeply thank my parents and my sister for their moral and

ﬁnancial support and their never-ending encouragement through out my education.

iii

TABLE OF CONTENTS

LIST OF FIGURES ........................................................................................................... vi
LIST OF TABLES ............................................................................................................ vii
1 INTRODUCTION ...................................................................................................... 1
l . l Conduction: ......................................................................................................... 1

1 .2 Convection: ......................................................................................................... 2
1.3 Radiation: ............................................................................................................ 2
1.4 Expanded Polystyrene (EPS) Containers: ........................................................... 4
1.5 Gas ﬁlled bag ...................................................................................................... 4
1.6 Vacuum Insulation Panels ................................................................................... 5
1.7 Insulated pallet blanket ....................................................................................... 6
1.8 Expanded Polyurethane Foam Containers: ......................................................... 7

2 LITERATURE REVIEW ........................................................................................... 9
2.1 Heat Transfer Basics ........................................................................................... 9

3 MATERIALS AND METHODS .............................................................................. 14
3.1 Phase 1: Prototype Boxes: ................................................................................. 14
3.1.1 Package A: ...................................................................................................... 14
3.1.2 Package B: ...................................................................................................... 15
3.1.3 Package C: ...................................................................................................... 16
3.1.4 Package D: ...................................................................................................... 16
3.1.5 Package E: ...................................................................................................... 17
3.1.6 Package F: ...................................................................................................... 18

3.2 Phase H: Production Boxes: .............................................................................. 18
3.2.1 Package G: ...................................................................................................... 19
3.2.2 Package H: ...................................................................................................... 19
3.2.3 Package 1: ....................................................................................................... 20
3.2.4 Package J: ....................................................................................................... 21

3.3 Test Methods: .................................................................................................... 21
3.3.1 Edge Crush Test: ....................................................................................... 21
3.3.2 Puncture Resistance Test: ......................................................................... 22
3.3.3 Thermal Analysis: ..................................................................................... 22
3.3.4 R-Value Measurement: ............................................................................. 25
3.3.5 Pre-shipment Test: ISTA Project 1A ........................................................ 26

4 RESULTS AND DISCUSSION ............................................................................... 29
4.1 R-value of Phase I Packages: ............................................................................ 29
4.1.1 R-value of Package Systems at Room Temperature: ................................ 30
4.1.2 R-value of Package Systems at High Temperature ................................... 31

4.2 R-value comparison of Phase 11 Packages ........................................................ 32
4.2.1 12 Hour R-value testing ............................................................................ 32
4.2.2 24 Hour R-value testing ............................................................................ 32

4.3 Thermal Analysis of Package Systems with Dry Ice and Ge] Ice .................... 34
4.3.1 Gel Ice at Room Temperature (74°F) ....................................................... 34
4.3.2 Gel Ice at High Temperature (104°F) ....................................................... 35
4.3.3 Dry Ice at Room Temperature (74 °F) ...................................................... 36
4.3.4 Dry Ice at High temperature (104°F) ........................................................ 37

iv

4.3.5 Puncture Resistance Test .......................................................................... 38

4.3.6 Edge Crush Test ........................................................................................ 40

4.4 Pre-shipment Test: ISTA Project 1A ................................................................ 41

5 SOURCES OF ERROR ............................................................................................ 42
5.1 Sources of Error in the R—value measurement: ................................................. 42

6 ENVIRONMENTAL ISSUES AND RECYCLABILIT Y ....................................... 43
7 CONCLUSIONS ...................................................................................................... 47
8 BIBLIOGRAPHY ..................................................................................................... 49

LIST OF FIGURES

Figure l-l Conductive heat transfer through an L shaped bar. .......................................... 1
Figure 1-2 Convection heat transfer through convection in a room ................................... 2
Figure 1-3 Heat transfer through radiation ......................................................................... 2
Figure 1-4 EPS Cooler ........................................................................................................ 4
Figure 1-5 Gas ﬁlled bag .................................................................................................... 5
Figure 1-6 Vacuum insulation panel. .................................................................................. 6
Figure 1-7 Insulated pallet blanket ..................................................................................... 6
Figure 2-1 Heat transfer across two-dimensional plane ..................................................... 9
Figure 3-1: Package A ..................................................................................................... 15
Figure 3-2: Package B ...................................................................................................... 15
Figure 3-3: Package C ...................................................................................................... 16
Figure 3-4: Package D ..................................................................................................... 17
Figure 3—5: Package E ...................................................................................................... 17
Figure 3-6 Graphic Representation of Aluminum Foil Laminate Structure ..................... 18
Figure 3-7: Package F ...................................................................................................... 18
Figure 3-8: Package G. .................................................................................................... 19
Figure 3-9: Package H. .................................................................................................... 20
Figure 3-10: Package 1. .................................................................................................... 20
Figure 3-11: Package J. .................................................................................................... 21
Figure 3-12: Time Temperature Indicator (Sensitech Inc.) .............................................. 24
Figure 3-13 Experimental setup of R—value measurement. .............................................. 26
Figure 3-14 Setup of Packages for Vibration and Drop Test ............................................ 27
Figure 3-15 Vibration Test Setup. ................................................................................... 27
Figure 3-16 Drop Test Setup ............................................................................................. 28
Figure 4-1 R-value Comparison of Phase I Packages ....................................................... 30
Figure 4-2 Effect of Temperature on R-value (Source: www.beaversplastics.com) ........ 31
Figure 4-3 Plot of Thermal Analysis of Packages with Gel Ice at Room Temperature. .. 34
Figure 4-4 Plot of Thermal Analysis of Packages with Gel Ice at High temperature. ..... 35
Figure 4-5 Plot of Thermal Analysis of Packages with Dry Ice at Room Temperature... 36
Figure 4-6 Plot of Thermal Analysis of Packages with Dry Ice at High Temperature ..... 37

"Images in this thesis/dissertation are presented in color."

vi

LIST OF TABLES

Table 2.1.1 Thermal conductivity and R-values of different materials. ........................... 10
Table 3.3.1: 'ITI Specifications (Source: www.sensitech.com) ....................................... 24
Table 3.3.2 Drop Sequence in Accordance with ISTA Procedure 1A .............................. 28
Table 4.1.1 R-value Results at Room Temperature .......................................................... 29
Table 4.1.2 R-value Results at High Temperature ............................................................ 29
Table 4.2.1: 12-Hour R-value Results of Box—in—Box Package Systems. ....................... 32
Table 4.2.2: 24-Hour R-value Results of Box-in-Box Package Systems. ....................... 32
Table 4.2.3 Speciﬁcations of Different Box-in-Box Packaging Systems ......................... 33
Table 4.3.1 Puncture Resistance Test Results. ................................................................. 39
Table 4.3.2 Edge crush test results .................................................................................... 40

vii

1 INTRODUCTION

Heat is a form of energy that can be transferred from one body to another. Heat
energy flows from a higher potential to a lower potential meaning that heat transfers from
a warmer body to a cooler body. This transfer takes place until both the bodies are in
thermal equilibrium. There are three ways by which the transfer of heat energy takes
place: 1) Conduction 2) Convection and 3) Radiation.

1.1 Conduction:

Conduction (Figure 1-1) is the transfer of heat energy in which heat is transferred
from particle to particle. In other words, heat energy is transferred from one medium to
another medium through atoms. The vibration of one atom in the body helps the adjacent
atom to vibrate thus transferring the energy to the entire body until thermal equilibrium is
reached. In conduction there is no actual movement of matter but only transfer of energy

takes place.

CROSS SECTIONAL AREA

 

 

 

 

 

HEAT FLOW COLD

 

HOT

 

 

\ ‘-———

 

 

 

 

 

 

 

 

 

Figure 1-1 Conductive heat transfer through an L shaped bar.

After conduction takes place both the surfaces that are in contact will have the

same temperatures.

1.2 Convection:

Convention (Figure 1-2) is the transfer of heat energy by actual movement of the
warmed matter. This type of transfer of heat energy occurs in gases and liquids. The hot
air in a room near the hot air vent displaces, and is replaced with cool air and the cycle is

repeated until equilibrium is reached.

 

Figure 1—2 Convection heat transfer through convection in a room

1.3 Radiation:

This process of heat transfer occurs when electromagnetic waves transport energy
through space (Figure 1-3). Electromagnetic waves that originate from the sun and pass
through space to earth is an example of radiation heat transfer. This type of heat transfer

requires no help from the medium. Radiation occurs even in vacuum.

\ /

 

 

/
Reflection
Raciation \ f
: : q : : :
\
Transm'ssion

Figure 1-3 Heat transfer through radiation

A package is considered to be a good insulator when it slows down the heat
transfer. Package insulation is a vital area of study in packaging because any
inadequacies in insulation can result in product damage and eventually lead to monetary
loss. Food products, frozen foods in particular have to pass through different temperature
cycles during manufacture, storage, and distribution. For instance, atypical frozen food is
manufactured in the plant and stored in the plant freezer before being shipped to a
warehouse. The package then is transported from warehouse to a retail store where it is
stored in a freezer case. The consumer then buys the product and takes it in a shopping
cart to home where it is stored in a freezer before it is consumed. Insulation becomes very
vital in the above case because the product is undergoing lot of temperature changes.

There are four main features that insulation packages should have (FedEx, 2001)

1. Keep products that are temperature sensitive within allowable temperature ranges.

2. Keep products frozen. This is applicable to products like ice cream, diary
products, vegetables, meat, seafood etc.

3. Prevent products from freezing. This is applicable to products like chemicals,
pharmaceuticals, blood and tissue samples, etc.

4. Attenuate the effect of temperature variation. This is applicable to electronic
products, polymers, ﬂowers etc.

There are different types of insulating containers that are available for packaging.

Each combination of materials and package conﬁguration addresses a speciﬁc need.

Some of the commonly used insulated packaging systems are discussed next.

1.4 Expanded Polystyrene (EPS) Containers:

Expanded polystyrene (EPS) is the most common insulation packaging material
used today (Figure 1-4). Air ﬁlled cells inside the EPS foam make it an excellent thermal
insulator. This is due to the fact that air has particularly low heat conductivity. Insulation
packaging from EPS helps perishable products from deteriorating over a long period of
time. They also provide uniform temperature distribution within the container. The
product is protected from rapid temperature changes, not only at the center of the
package, but also near the walls. These containers are lightweight, durable and
inexpensive. The facts that they do not produce Chloro Floro Carbons (CFC’s) make

them Eco-friendly packages. EPS coolers are also easily recyclable.

 

Figure 1-4 EPS Cooler

1.5 Gas ﬁlled bag

Gas-ﬁlled bags (Figure 1-5) are also used as good insulators. These bags are made of
plastic ﬁlms with internal bafﬂes that prevent convective heat transfer. This bag is ﬁlled
with air or an inert gas such as argon, krypton or xenon. The air inside the bag acts as a

thermal insulator. These bags are placed inside the corrugated boxes wrapped around the

product. These bags are very space-efﬁcient when not in use, since they can be
transported ﬂat to the shippers. This saves valuable space in the warehouse and also

reduces the transport costs.

 

Figure 1-5 Gas ﬁlled bag

1.6 Vacuum Insulation Panels

Vacuum Insulation Panels (Figure 1-6) are even more effective insulation
materials compared to polyurethane or expanded polystyrene. The vacuum insulation
panels have an R-value of up to 30 whereas the R-values of Polyurethane and Expanded
Polystyrene range from 4 to 10. A vacuum panel is made of a core material, a metal foil
or a metallized barrier ﬁlm. The core material is sealed to the barrier ﬁlm or foil by
applying pressure in presence of vacuum. The high R-value of the vacuum panel makes it

an excellent insulator.

 

Figure 1-6 Vacuum insulation panel.

1.7 Insulated pallet blanket

Insulated pallet blankets (Figure 1-7) are another type of insulation packaging
materials that are widely used for shipping perishable products like fruits, candies and
medical supplies. The blankets are made of 0.25 inches of microfoam lined with
aluminum foil. The microfoam is made of low-density polypropylene, which is very
ﬂexible. The reﬂective surface of the blanket radiates heat outward and retains inward

heat.

 

Figure 1-7 Insulated pallet blanket

1.8 Expanded Polyurethane Foam Containers:

Polyurethane foam is injected between the Regular slotted corrugated container and
the insert as shown in the ﬁgure below. A rectangular cushion foam piece is used to cover
the product from the top. The air ﬁlled foam inside these containers provides good barrier
and delays heat transfer making these containers excellent insulators. The polyurethane
foam used in the side and bottom sections of these containers is also referred to as

“Foam-In-Place”.

 

Figure 1-8 Polyurethane Foam Container

The objective of this research was to compare and analyze the insulation
effectiveness of various new packaging materials. The packaging systems that were
studied have been described in the materials and methods section of this thesis. The
following are the speciﬁc objectives of this research:

1) To evaluate the insulation effectiveness of new packaging systems.

2) To measure and compare the R-values of various packaging systems.

3) To perform distribution testing on these package systems for single parcel

shipments.

2 LITERATURE REVIEW

This chapter discusses some of the various heat transfer mechanisms that inﬂuence
the performance of insulated packages.
2.1 Heat Transfer Basics
Heat Transfer occurs whenever there is a difference in temperature in a medium.
If the medium is stationary and there exists a temperature difference, the type of heat
transfer that occurs is called conduction. The heat conduction rate across a one-
dimensional plane (Figure 2-1) of length “L”, and having a temperature of T1 on one side
and T2 on the other side is (Incropera, 2002):
H = Ell—T
L
AT = T1-T2
L = Length of the Plane
k: Co-efﬁcient of thermal conductivity

H: Heat ﬂux per unit area.

 

HEAT FLOW
T1 T2

w/

 

 

 

 

 

/\
1"
v

Figure 2-1 Heat transfer across two-dimensional plane

Since, H is the Heat ﬂux per unit area, the heat rate “Q” by conduction through a

plane wall of area is

Q=HxA

Thermal conductivity (k) is the rate at which the heat ﬂows in a material. The thermal

conductivity is a material property and is constant for a particular material. Lower value

of the k means the material is a better insulator. The thermal resistance, which is also,

known as R-value is the reciprocal of thermal conductivity. Therefore higher R-value

means the material is a good insulator. The k and R-values of different materials with a

thickness of 1” and cross—sectional area of 1 sq.ft. (Table 2.1.1).

Table 2.1.1 Thermal conductivity and R-values of different materials.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

MATERIAL CONDUCTIVITY ("k") THERMAL RESISTANCE ("R"):
Copper 2712 0.00037
Aluminum (6061) 1 160 0.00086
Glass 5 0.2
Polyethylene Foam 0.43 2.33
Wood (dry) 0.33 3.03
Glass Wool 0.29 3.45
Polystyrene (expanded) 0.28 3.57
Polystyrene (extruded) 0.21 4.8
PVC (Klegecell) 0.21 4.8
Polyurethane Foam 0.17 5.88
Air 0.16 6.25
BARRIER Ultra-R 0.02 50.36
Total Vacuum 0.004 250

 

 

 

Heat transfer through convection is caused by the motion of the ﬂuid (liquid or

gas). Depending on the nature of the ﬂow, convection heat transfer can be classiﬁed into

two categories 1) forced convection and 2) free or natural convection. Forced convection

10

is caused by external means like winds. Free or natural convection is a result of density
differences caused by temperature variations in a ﬂuid.

The heat transfer rate equation in convection process regardless of the convection
type is

Q = h (T s - Ta)

Q = Convective heat ﬂux

T S = Temperature of the surface (in °K)

Ta = Temperature of the Fluid (gas or liquid) in °K

h = Convective heat transfer coefﬁcient (W/m2 K)

Unlike in conduction or convection, radiation does not require an intervening
medium to transfer the heat. Radiation can transfer the heat even through vacuum. The
corresponding equation for radiation heat transfer is

H = ecrAT'1

H = Radiation heat ﬂux

e = emissivity (0-1)

0: Stefan-Boltzmann constant = 5.67 x 10'8 J/(s-mz-K4)

A = surface area of object

T = temperature (in °K)

Heat transfer is inﬂuenced by many factors such as boundary surfaces, thickness
of the air space, distance between the boundary surfaces and the direction of the heat

ﬂow. The above-mentioned factors particularly affect heat transfer through conduction

ll

and convection. The mean temperatures of the surfaces minutely affect conductive and
convective heat transfers. Heat transfer through radiation is affected by surface properties
of the material like its emissivity. The thickness of the air space and the direction of the
heat ﬂow have very little effect on heat transfer through radiation (ASHRAE, 1997).
Thermal resistance (R-value) in packaging depends on the wall construction and inside
area of the package because that is what limits the heat transfer of the product inside the
package (Burgess, 1999). The temperature difference between outside environment and
inside the package also affects the R-value.

The R-values of the package systems can be measured by taking the combined effects of
conduction, convection and radiation (Burgess, 1999). The contribution of conduction to
the overall R-value depends on the total thickness of the package system. For example, if
the package system has a corrugated container and EPS foam inside it, the thickness of
the package will be the sum of thickness of corrugated container and the EPS foam.

The contribution of convection in the overall R-value depends on the number of
surfaces in contact with outside environment. For instance, for a corrugated box with EPS
foam panels inside it, the number of surfaces in contact will be ﬁve. The outside and
inside surface of the box, the two faces of the EPS foam panels and the product.

The contribution of radiation in overall R-value depends on the number of reﬂective
surfaces on the package. Aluminum foil laminated boxes are good examples of reﬂective
surfaces.

The overall R-value, which takes into account, the heat transfer through
conduction, convection and radiation, can be calculated by using the equation below

(Burgess, 1999).

12

Package R-value = 3.9 th + 1.5 np+ 3.2 nf
where th is the overall thickness of the package in inches, up is the number of plain
surfaces and nf is the number of reﬂective surfaces. The above equation can predict R-
value with 20% accuracy. Surfaces are considered plain if they are not covered with
aluminum foil or any other reﬂective surface. The main advantage of the above equation
is to estimate approximate amounts of ice that would be needed to keep the product cool
inside the package. The equation below is used to calculate the approximate amount of
ice needed.
Amount of ice (lb) = (Inside grea of the box) (tempergture difference) (hours exposed)
(R-value) (Latent heat)
For instance a corrugated container having an inside dimensions of 12 x 12 x 12 inches
and a R-value of 6, if exposed for 24 hours at 72°F, would require
= (6) (72-32) (24)
(6) (144)
= 6.7 lbs of ice

So, it would take 24 hours for 6.7 lbs of ice to melt inside the corrugated container
having a product. After the 6.7 lbs of ice has melted, the temperature of the product
would start to rise gradually. If the product is frozen prior to packing and contains water
in it, it will contribute to the ice requirement. For example, 5 lbs of a frozen food product
has about 2 lbs of water in it. Therefore, in the example above, only 4.7 lbs of ice would

be required (Burgess,l999).

13

3 MATERIALS AND METHODS
The different materials and package types that were evaluated in this study are
described in this section.
3.1 Phase 1: Prototype Boxes:
During the ﬁrst phase of this study, prototype packages were constructed from the
test materials and preliminary heat transfer characteristics compared. Based on the
performance of this data, production run containers were tested in the second phase to

validate the performance. The prototype packages are described below.

3.1.1 Package A:

This package was made of a single wall C-ﬂute corrugated board with inside
dimensions of 12 x 12 x 12 inches. This corrugated container was a full overlap type
(FOL). Six foam panels made of Expanded Polystyrene (EPS) were placed inside the
package as shown below in Figure 3-1. The thickness of the EPS foam panels was 0.5

inch. The bursting strength of the ﬁberboard was 200 psi.

14

 

Figure 3-1: Package A
3.1.2 Package B:
This package was similar to Package A, but used a 0.75 inch EPS foam panels. It
was also made from single wall C-ﬂute corrugated board with inside dimensions of 12 x

12 x 12 inches. This corrugated ﬁber box was also a full overlap type (FOL).

 

Figure 3-2: Package B

3.1.3 Package C:

In this package, the material used is Thermal-Cor®. The Thermal-Cor® material
is manufactured by extruding EPS foam between two layers of paper. The material was
then formed into test packages (Figure 3-3). The inside dimensions of the box were also

12 x 12 x 12 inches, and the style was FOL.

 

Figure 3-3: Package C.

3.1.4 Package D:
This package uses the same container as Package C, but in addition had a foil bag
inside the box (Figure 3-4). The foil bag was made of an aluminum laminate. The product

that is to be packaged was placed inside the foil bag before the container is sealed.

 

Figure 3—4: Package D

3.1.5 Package E:

The package also uses the same container as Package C but in addition to the
Thermal-Cor® container, the system has a rectangular Thermal-Cor® tube, which was
placed, inside the box as shown in Figure 3-5. The Thermal-Cor® tube was made of the

same material as the box.

 

Figure 3-5: Package E

3.1.6 Package F:

This container was also a FOL type (Figure 3-7). The inside dimensions of this
box were 12 x 12 x 12 inches. This box was made up of ﬁve layers as shown in Figure
3-6. The two outer layers are aluminum foil and contain a three layer Thermal-Cor®

structure sandwiched in between.

 

 

f\l\/\/\l\/

 

Figure 3-6 Graphic Representation of Aluminum Foil Laminate Structure

 

Figure 3-7: Package F

3.2 Phase II: Production Boxes:
The second phase of the project involved testing production run fabricated boxes.

The second phase of boxes were made based on the test performance data of Phase I.

3.2.1 Package G:

This type of package system contains a Thermal-Cor® box inside another
Thermal-Cor® box. There was a gap of 0.5 inches between the two boxes. Small square
pieces of EPS foam cushion were glued in the middle of all the faces of the outside
surface on the inner box as shown in the (Figure 3-8). The internal dimensions of the

inside box were 11 x 11 x 11-5/8 inches.

 

Figure 3-8: Package G.

3.2.2 Package H:

This type of package system contained a foil laminated Thermal-Cor® box inside
another Thermal-Cor® box. There was a gap of 0.5 inches between the two boxes. The
box-in-box was constructed similar to Package G and is shown in Figure 3-9. The

internal dimensions of the inside box were 9 x 9 x 9-5/8 inches. The internal dimensions

of the outside box are 10-9/16 x 10-9/ 16 x 11-13/16 inches.

 

Figure 3-9: Package H.
3.2.3 Package 1:
Package I contained a Thermal-Cor® box inside a foil laminated Thermal-Cor®
box. There was a gap of 0.5 inches between the two boxes. The construction of the box-
in-box was similar to Package G and is shown in Figure 3-10. The internal dimensions of

the inside box were 9 x 9 x 9-5/8 inches.

 

Figure 3-10: Package 1.

20

3.2.4 Package J:

This package system contained a foil laminated Thermal-Cor® inside another foil
laminated Thermal-Cor® box. This also had a 0.5-inch gap between the two boxes.
Figure 3-11 shows this package type. The internal dimensions of the inside box were 9 x
9 x 9-5/8 inches. The internal dimensions of the outside box were 10-9/16 x 10-9/ 16 x

11-13/16 inches.

 

Figure 3-11: Package J.

3.3 Test Methods:
The following test methods were used to compare the performance of these

containers.

3.3.1 Edge Crush Test:

In this test the resistance of the paper board when subjected to edge crushing was
measured. The Edge Crush Test (ECT) is a good measurement to determine the
performance of a container, in the sense that it will give an assessment with regard to the

stacking strength and the bending stiffness of the corrugated walls.

21

Rectangular specimens of 2 inches width and approximately l-‘A inches in height
were taken and placed in a compression tester in accordance with TAPPI T 811 standard.
The load is applied perpendicular to the ﬂutes of the specimen and the largest amount of
force the specimen can withstand without being crushed is determined. This force
calculated per unit length of the specimen is the edge crush strength of the board. The
results of this test are discussed in the next chapter. Ten samples were tested for the new

Thermal-Cor® material and ﬁve samples each of corrugated board and foil-laminated

Thermal-Cor® board were tested.

3.3.2 Puncture Resistance Test:

This test determines the amount of energy required to puncture a corrugated
ﬁberboard. This energy is a combination of energy required to tear the board and energy
to bend the material out of the puncture. Six samples were cut to 12 x 12 inches size in
accordance with the TAPPI T 803 standard. The specimen to be tested is mounted and a
latch is pulled to release the impacting pendulum mass. Before releasing the pendulum,
sufﬁcient amount of weights should be put on the stud so that the pointer will stop within
the scale reading. The values obtained in this test are in Beach Puncture Units, which can

be converted into in-lb using a multiplying factor of 0.265.

3.3.3 Thermal Analysis:

In this experiment, the temperature change inside a test package is measured with
respect to time. The heat transfer in the test packages was evaluated in an environmental

chamber at 104° F and at room temperature (72°F) for 48 hours.

22

Replicates of packages were prepared and 5 pounds of gel ice was placed inside
the packages and Time Temperature Indicators (’ITI’s) (Figure 3-12) were placed inside
the test packages. These 'I'I'I’s were activated before placing them inside the package.
The TI‘I’s record the temperature inside the package every 60 seconds. The recorders are
equipped with a memory chip, which stores this data. This data can be erased and the TH
can be reused. When the temperature recorders were placed inside the package, great care
was taken to make sure that tip of the recorder was not in contact with gel ice pouches or
dry ice during storage. Only the air temperature inside the package was monitored. The
packages were then sealed with a foam tape. The boxes, EPS foams, foil bags, inserts and
gel ice used in this process were pre-conditioned for 24 hours at frozen temperatures (20°
F) prior to testing.

The above experimental procedure was repeated by using 5 lbs of dry ice. The
TTI’s were placed in the packages the same way as they were placed in the above case
with gel ice. The boxes, inserts and foil bags used in this process were also conditioned at
frozen temperatures (20°F). Unlike gel ice, dry ice was not preconditioned for 24 hours
in the freezer.

After 48 hours the packages were taken out from the environmental chamber and
the ambient room conditions. The packages were then Opened and time temperature
indicators were taken out and were connected to the computer to obtain the temperature
proﬁle data of the boxes for 48 hours. Microsoft Excel Spread Sheet was used to import
the data from the 'ITIs. Graphs were plotted to evaluate the temperature proﬁle of all the

packages.

23

 

Figure 3-12: Time Temperature Indicator (Sensitech Inc.)

Table 3.3.1: TTI Speciﬁcations (Source: www.sengiggﬂQm

 

Operating Range

-22°F to +185°F (-30°C to +85°C)

 

lSensing Options

Ambient, SS Probe
Flex Probe
Pulp Probe ( 16,000 data pts only)

 

Sensor Accuracy

i2°F from -22°F to 0°F (il°C from -30°C to -l 8°C)
il°F from 0°F to +122°F (i0.5°C from -18°C to
+50°C)
i2°F from +122°F to +185°F (i1°C from +50°C to
85°C)

 

Memory Size

2,000 or 16,000 Data Points

 

Temperature
Alarms

Red/Green LED Alarm

 

Start-Up Delay

Minimum - 0 Minutes
Maximum - 20 Days

 

‘Measurement
Interval

Minimum - 30 Seconds

Maximum - 120 Minutes 2k data points
Maximum - 32 minutes 16k data points

 

 

Sensor Resolution

 

 

0.l°(l/l0°)

 

24

3.3.4 R-Value Measurement:

R-value measurements (Burgess, 1999) were conducted to measure the thermal
resistance of each package. The packages were stored at two different temperatures: 74°F
and 104°F. In this procedure sufﬁcient quantity of ice was taken in a bucket and was
preconditioned for several hours until some of the ice starts melting. The water was then
drained out and the bucket and remaining ice was placed inside the package (Figure
3-13), sealed and stored in both the environmental chamber (104°F) and ambient room
(74°F). The packages were checked every ﬁve hours to see if most of the ice melted. This
was done by slightly shaking the packages. If a rattling sound was heard, it indicated the
presence of ice that had not melted. The packages were then taken out of the storage
conditions and opened. The ice was removed and the remaining water weighed. The
length of the storage time and weight of ice melted was used to determine the melt rate.
This was used to calculate the R-Value of the package system using the equation:

System R-value = (Inside area) (Temperature difference)
(Melt rate) (Latent heat)

Melt rate is the amount of the ice melted divided by the storage period. Latent
heat is the amount of heat energy required for 1 lb of a substance to change its phase from
solid to liquid or liquid to gas without changing its temperature. The energy required to
melt 1 lb of ice is 144 Btu. The temperature difference is the difference in the
temperature of the storage environment (74°F or 104°F) and the temperature inside the

package (32°F).

25

 

Figure 3-13 Experimental setup of R-value measurement.

3.3.5 Pre—shipment Test: ISTA Project 1A

The package systems were subjected to vibration and drop testing to evaluate their
performance during transportation and distribution. Sand was ﬁlled in bags and was
properly taped to secure sand from coming out of the bags. The bags were then placed in
the packages as shown in the Figure 3-14. The bags were secured in the packages using
foam-in—place packaging. The package was then placed on a vibration table (Figure 3-15)
for 60 minutes at a frequency of 4 Hz. The procedure used in this test was in accordance
with ISTA (International Safe Transit Association) Procedure 1A. The test duration can
be detemrined by using the following equation:

Test Duration in Minutes = 14,200 vibratog impacts
Cycles per second (Hz) x 60

= 14 200 vibrato irn acts
4 x 60

= 59.16 (approximately 60 minutes)

26

 

Figure 3-15 Vibration Test Setup.

Aﬁer the vibration test, the packages were dropped from 30 inches height using a
drop test machine (Figure 3-16). The following ten-drop sequence was used to drop the

packages.

27

Table 3.3.2 Drop Sequence in Accordance with ISTA Procedure 1A.

or comer
not use
the comer
comer
comer

Face

 

Face

After performing the ten-drop sequence above, the packages were visually inspected for

any failure.

 

Figure 3-16 Drop Test Setup

28

4 RESULTS AND DISCUSSION
4.1 R-value of Phase I Packages:
The ﬁve packages were tested for R-values in accordance with the procedure
described in 3.3.4. The results of the test are shown in Table 4.1.1 and Table 4.1.2 and

graphically shown in Figure 4.1.1.

Table 4.1.1 R-value Results at Room Temperature

 

 

 

 

 

 

 

 

 

 

 

Room Temperature (74°F)
System Type Sample # R-value Average St.Dev

Packgge A 1 8.88 9.43 0.7778
2 9.98

Package B 1 8.00 8.99 1.4
2 9.98

Packggg C 1 8.00 7.34 0.9404
2 6.67

Package E 1 8.00 8.00 0
2 8.00

Package F 1 13.33 13.33 NIA
2 MIA

 

 

 

 

 

 

 

Table 4.1.2 R-value Results at High Temperature.

 

 

 

 

 

 

 

 

 

 

 

High temperature (104°F)
System Type Santile # R-value Averagg St.Dev

Package A 1 6.28 5.87 0.587
2 5.45

Package B 1 5.55 5.7 0.2
2 5.84

Pacgge C 1 5.84 5.84 0
2 5.84

Package E 1 6.25 6.25 0
2 6.25

Package F 1 6.26 6.26 MIA
2 MIA

 

 

 

 

 

 

 

29

Average R-value plot for Room Temperature(74°F) and High temperature
(104°F)

E
is
ﬁf‘é.
ma

5'

15~

     

 

 

0 j .
;Package A ‘Package B Package C ‘Package E (Package F i
i. Room Temperature 1 9.43 i 8.99 i 7.34 i 8.00 i [3.33 l‘
l . O l i ' ' "
UHIgLTﬂMaLWij f2 -1 .5337, - 347,1- 5-84 i 6-25 l 6-26 J
Type of package systems

Figure 4—1 R-value Comparison of Phase I Packages.

4.1.1 R-value of Package Systems at Room Temperature:

The R-value average of Package A obtained in the results was greater than that of
Package B (Figure 4-1). The thickness of the EPS foam used in Package A is 0.5 inch
whereas the thickness of the EPS foam used in Package B is 0.75 inches. The R-value
depends on property of the material, density and its thickness. Since, the material used in
both the systems was EPS of the same density, the thickness dictates the system R-value.
The greater the thickness, greater is the R—value. The R-value of Package E was greater
than that of Package C. This is due to the fact that in former there is a Thermal-Cor®

tube inside the package, which acts, as an extra layer of protection whereas in the latter,

there is no such additional thermal barrier.

30

Package F has a greater R-value based on the data in Table 4.1.1 and Table 4.1.2.
This is attributed to the aluminum surfaces that act both as convection and radiation

barriers (Burgess, 1999).

4.1.2 R-value of Package Systems at High Temperature

The system R-value decreased with increase in temperature from room
temperature to 104 °F. The same decreasing trend of R-value with temperature increase
has also been found in other insulating materials such as Terrafoam, which is a closed
cell Expanded polystyrene foam manufactured by Beaver Plastics, Canada. The graph
(Figure 4-2) below illustrates how the R-value of Terrafoam changes with respect to

temperature.

Effect of Temperature on R-VALUE of Terrafoam

 

 

 

R-value

 

 

 

 

3.5 .
-10 -4 2 8 14 20
Temperature (°C)
— — - Terrafoam 1 Terrafoam 2 Ten'atoam 3

 

 

Figure 4-2 Effect of Temperature on R-value (Source: www. beaversplastics. com)

From the results it can be seen that the R-value of Package F is slightly higher as

compared to other package types.

31

4.2 R-value comparison of Phase II Packages
Table 4.2.1 and Table 4.2.2 below show the 12-hour and 24-hour R-value tests of

all box-in-box package systems tested in Phase 11.

4.2.1 12 Hour R-value testing
Table 4.2.1: 12-Hour R-value Results of Box-in-Box Package Systems.

 

 

 

 

 

 

 

 

 

System R-value
Package Inside Box Surface (sq.ft x °F x hl Average
system Sample # area (sq.ft) BTU) R-value
Pacgge G 1 5.23 7.267 7.3
2 7.267
PackagH 1 3.53 9.8 9.8
2 9.8
Package 1 1 3.53 8.4 8.4
2 8.4
Package J 1 3.53 9.8 9.8
2 9.8

 

 

 

 

 

 

 

4.2.2 24 Hour R-value testing

Table 4.2.2: 24-Hour R-value Results of Box-in-Box Package Systems.

 

 

 

 

 

 

 

 

 

System R-value
Package Inslde Box Surface (sq.ft x °F x hl Average
system Sample # ama (sq.ft) BTU) lit-value
Package G 1 5.23 7.93 7.9
2 7.93
Package H 1 3.53 9.8 9.8
2 9.8
Package I 1 3.53 8.407 8.4
2 8.407
Package .1 1 3.53 9.06 9.1
2 9.06

 

 

 

 

 

 

 

32

Table 4.2.3 Speciﬁcations of Different Box-in-Box Packaging Systems.

 

 

 

 

 

 

 

 

 

 

 

Outer box Inside box
Package Outer box Inside box dimensions dimensions
system type type (inside) (inside) Gap
Thermal- Thermal- 12-9116 x 12_
G Cor® Cor® 9116X13-13116 11 X11 X11-518 112 "
Thermal-
Thel'ma" Cor®Foil 10-9116 x 10-
H Cor® Laminated 9116 X11-13116 9 X 9 X 9-518 112 "
Thermal-
Cor® Foil Therm" 10-9116 x 10-
l Laminated Cor® 9116 X11-13116 9 X 9 X 9-518 112 "
Thermal- Thermal-
Cor®Foil Cor®Foil 10—9116 X 10-
J Laminated Laminated 9116 X11-13116 9 X 9 X 9-518 112 "

 

 

From the above Table 4.2.1 and Table 4.2.2, it can be seen that the R-value of
Package G is lower compared to the other package types. Both the inside and the outside
box in this package are made of Thermal-Cor®. These systems are known to have less
insulation effectiveness compared to foil laminated Thermal-Cor® systems. The outside
and inside box in Package J is made of Thermal-Cor® foil laminated materials and has

greater R-value compared to the other systems. Package H has greater R-value than

Package 1. This could be due to the fact that in Package H the inside box is a Foil
Laminated Thermal-Cor®, whereas in Package 1, the inside box is made of Thermal-

Cor®. The R-Values of 12-hour and 24-hour tests showed the same trend.

33

4.3 Thermal Analysis of Package Systems with Dry Ice and Gel Ice

4.3.1 Gel Ice at Room Temperature (74°F)

There was a steep rise in temperature inside the box for the ﬁrst few hours inside
all packages (Figure 4-3). The Package D reached equilibrium with outside temperature
faster than the other packages. The temperature change in Packages A and B was slower
because of the presence of EPS foams, which act as good insulators. The package E,
which has a Thermal-Cor® tube inside was also effective in terms of slowing the heat
transfer. It can be seen from Figure 4.3 that by the end of ﬁrst 24 hours of storage,
temperature inside the Packages A, B, E and F were a few degrees less as compared to
Packages C and D. All the packages reached equilibrium with outside temperature after

48 hours.

Thermal Analysis Plot of Phase I Packages with Gel Ice at Room
Temperature

 

 

 

 

20

TEMPERATURE (F)
8

 

o T T f T l
0 1 0 20 30 40 50

TIME (HOURS)

 

—AVG.Package A —AVG.Package B —- AVG.Package C
—— Package D —Avg Package E — Avg Package F

Figure 4-3 Plot of Thermal Analysis of Packages with Gel lce at Room Temperature.

34

4.3.2 Gel Ice at High Temperature (104°F)

During the ﬁrst few hours of storage the temperature rise was steep like the Gel
Ice stored at room temperature (Figure 4-4). Although the rates of heat transfer in
Packages A, C, D and B were different; all packages reached equilibrium with chamber
temperature at the end of the ﬁrst 24 hours. It can be seen from the graph that the
temperature inside Package A was closer to 118°F after 20 hours of storage and then the
temperature dropped down and was in equilibrium with chamber temperature after a few
hours. The temperature inside the package cannot be more than the chamber temperature
but this probably occurred because of sensor overshoot. The temperature change in

Package F was slower compared to all the other packages.

Thermal Analysis Plot of Phase I Packages with Gel Ice at High Temperature
(104°F)

 

 

TEMPERATURE (F

 

o T T T T I
0 10 20 30 40 50

TIME (HOURS)

 

— AVGPackage A — AVGPackage B —AVG.Package C
——- Package D — AVGPackage E —-AVG Package F

Figure 4-4 Plot of Thermal Analysis of Packages with Gel Ice at High temperature.

35

4.3.3 Dry Ice at Room Temperature (74 °F)

Unlike gel ice at room temperature, the temperature inside the packages dropped
drastically for the ﬁrst few hours with dry ice (Figure 4—5). This is probably because the
dry ice changes its phase from solid to gas (sublimes) and convective heat transfer will
take place resulting in dropping of temperatures for the ﬁrst few hours. In other words,
when the dry ice becomes gas it cools down the temperature inside the package until the
temperature inside the package becomes constant and ﬁ'om that point the temperature
starts rising to get in equilibrium with outside chamber temperature.

The Thermal-Cor® tube inside Package E acts as a barrier, which delays the rise
in temperature. The aluminum lamination in Package F acts against convective heat
transfer resulting in slow temperature rise. All the packages reached equilibrium aﬁer 48

hours.

Thermal Analysis Plot of Phase I Packages with Dry Ice at Room
Temperature

 

 

 

L1: 2
“I
m
D
5
[LI
0.
E
I.”
h l
o * l l l l l
0 10 20 30 40 50
TIME (HOURS)

— AVG.Package A — AVG.Package B —-- AVG.Package C
M Package D —AVG.Package E -—- Package F

Figure 4-5 Plot of Thermal Analysis of Packages with Dry Ice at Room Temperature.

36

4.3.4 Dry Ice at High temperature (104°F)

The temperature inside Package F decreased for the ﬁrst few hours (Figure 4-6). It
was discussed earlier that aluminum foil acts as a convective and radiation barrier. So, the
temperature fell down for few hours while the dry ice sublimed. The heat transfer through
F was much less compared to the other packages. At the completion of 48 hours storage,
the temperature inside package F was much lower than the other packages tested.
Packages A and B reached equilibrium with chamber temperature within ﬁrst 15 hours of
storage while C, D and E took almost 30 hours to reach equilibrium with chamber

temperature .

Thermal Analysis Plot of Phase I Packages with Dry Ice at High
Temperature

120 -

 

 

 

 

 

80“

TEMPERATURE (F)
8

 

 

o l T T T j
0 10 20 30 4O 50
TIME (HOURS)

— AVG.Package A — AVG.Package B — AVG.Package C
—— Package D —AVG.Package E — Package F

Figure 4-6 Plot of Thermal Analysis of Packages with Dry Ice at High Temperature.

37

4.3.5 Puncture Resistance Test

In the puncture resistance test, the results were obtained in beach units. The
values were converted into inches-pound (in-lb) by multiplying with a factor of 0.265. It
can be seen from the Table 4.3.1 that the puncture resistance of Thermal-Cor® was
higher compared to that of corrugated samples and aluminum foil laminated board. The
resistance of corrugated board and Foil Laminated Thermal-Cor® were found to be

similar.

38

Table 4.3.1 Puncture Resistance Test Results.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Sample
Sample Type Number Beach Unit in.-lb.
Thelma-Core (gagigg'ggcbﬁ) 1 445 117.93
2 445 1 17 .93
3 445 1 17.93
4 450 1 19.25
5 455 120.58
6 445 1 17.93
Average 447.5 118.59
ST.Dev 4.2 1.1
“ ‘11“ .... .- .- in” _ Sample Beach Unit in.-lb.
Edugated Box (Packa s A & B 1 355 94.08
2 355 94.08
3 365 96.73
4 360 95.40
5 365 96.73
6 360 95.40
Average 360.0 95.40
ST.Dev 4.5 1.2
Sample Beach Unit in.-lb.
oIIJIagnﬁdio‘i—"E‘ “37 ' 1 355 94.08
2 355 94.08
3 385 102.03
4 355 94.08
5 355 94.08
6 355 94.08
Average 360.0 95.40
ST.Dev 12.2 3.2

 

 

 

 

 

39

 

4.3.6 Edge Crush Test

The Edge Crush Test results Obtained from the test were in lb/2 inches because
the load was applied on a sample, which was 2 inches wide. The results were divided by
two to get the force applied per inch. The ECT of Thermal-Cor® was almost 2.5 times

greater than that of corrugated board and aluminum foil laminated board (Table 4.3.2).

Table 4.3.2 Edge crush test results

(OGVODU'IhODN-A

10

 

40

4.4 Pre-shipment Test: ISTA Project 1A
All the packages passed the ﬁxed displacement vibration test and drop test. There

was no product leak or failure during vibration or during the ten-drop sequence.

41

 

5 SOURCES OF ERROR

This chapter focuses on the sources of error of the R-value measurements Of
packages.
5.1 Sources of Error in the R-value measurement:
1) A plastic bucket is used in R-value measurement. This bucket is placed inside the
package with ice inside it. This bucket provides extra insulation for the ice. But since the
bucket is used in every package type, this effect is the same for all packages containing
the same amount of ice to start with.
2) The formula for R-Value measurement seems to hold good for single packages. It does
not seem to be good for box-in-box systems like the once discussed in Phase II of this
thesis. The equation takes into account the inside surface area of the inside box but a
single corrugated container having the same inside dimensions may have comparable R-
value to a Box-in-Box package with smaller area. The air gap is not accounted for in the

performance of the box-in-box systems when using the R-value equation.

42

6 ENVIRONIVIENTAL ISSUES AND RECYCLABILITY

Environmental Protection Agency (EPA) is encouraging businesses to practice 3 Rs

(Reduce, Reuse and Recycle) before considering materials for packaging their products.

Reduce: Source reduction (also called waste prevention) reduces the consumption
and discarding of materials. This includes purchasing durable, long-lasting materials and
seeking products and packaging that are free of toxic substances. It may involve
redesigning a product to use fewer raw materials in production, choosing materials that
have a longer life, or reusing the products. Source reduction decreases waste generation
and is the most preferable method of waste management that can go a long way toward

protecting the environment.

Reuse: Reusing materials by reprocessing them, donating them to charity and
community groups, or selling them will help reduce waste generation into the
environment. Use a product more than once, either for the same purpose or for a different
purpose. Reusing, if possible, is preferable to recycling because the material/product does

not need to be reprocessed before it is used.

Recycle: Recyclability is a vital issue in considering the material for insulation
packaging. The materials used should be recyclable after their usage. The recyclability of
EPS and corrugated ﬁberboard, which were used extensively in this research, are
discussed in this chapter.

EPS being a thermoplastic can be continuously melted and reformed which makes

it an excellent recyclable material. Low levels of residual styrene found in EPS are

43

environmentally safe for the use of material in packaging. Food and Drug Administration
(FDA) has approved Expanded Polystyrene for use in food contact packaging. Health
organizations encourage the use of EPS, as it does not support the growth of bacteria.

However, because of its lightweight, the volume by weight ratio of EPS is so
large that it would take several trucks to transport couple of tons of EPS. This will
increase the transportation costs and accounts for half the recovery costs. Several
companies have explored new ways to recycle EPS in an economic way. One such
procedure is by dissolving EPS in d-limonene. d-limonene, which is also known as
orange terpenes, is a bio-degradable solvent and can dissolve large blocks of the material
in a very short time. The d-limonene and EPS mixture occupies only 5% volume of the
original EPS foam. This mixture can then be economically transported to the recycling
plants.

EPS when incinerated will yield about 17000 to 18000 BTU of energy, which is
more than coal. Complete combustion of EPS produces carbon dioxide and water vapor
makes it a good source of fuel. The only organic volatile gas that is found in EPS is 3-6%
by weight of pentane. Usually manufacturers collect and destroy it according to local and
federal regulations.

Recycled EPS foam can be used to make a number of versatile materials and end
products that include:

1) Remolded foam, which can be used in loose ﬁll packaging.
2) Plastic applications such as stationary products, coat hangers etc.

3) Extruded applications such as furniture etc.

4) EPS can be reused as lightweight concrete material and may also be mixed with
cement for insulating structures like swimming pools, ﬂoors, roofs etc

Corrugated containers are extensively used in packaging industry and this makes
them a major component in the waste stream by weight. At the same time, corrugated
containers are easily recyclable making them the most recycled packaging material by
weight. Used corrugated containers are also called “Old Corrugated Containers” (OCC)
in the recycling industry.

In this present research, the materials used were mostly ﬁberboard and EPS.
However, in some packages EPS was sandwiched between ﬁberboards. The Packages A
and B, which have corrugated containers and EPS foam panels are easily recyclable as
compared with the other packages as there is no separation of the materials involved but
Package A and B use more material compared to the other packages and this will not
contribute to the Objective of source reduction. However, EPS foams and corrugated
ﬁberboard in the packages can be reused. Packages C, E and F are hard to recycle and
expensive because the ﬁberboard and EPS have to be separated from each other. This
separation process may leave EPS contaminants in the ﬁberboard and ﬁberboard
contaminants in the EPS, which makes the recycling process more complicated.
However, these packages use less material and contribute towards the goal of source
reduction. The packages can also be reused.

Packages G, H, J and I are box-in-box systems and these packages are very
expensive to recycle and do not contribute much to source reduction because there is a lot

of material involved. In some of these packages, boxes are laminated with foil adding one

45

more step to the recycling process and also the scope for contamination is increased. In

fact, in some cases, boxes with plastic extrusions and laminates are not recycled.

46

7 CONCLUSIONS

The following conclusions were reached in this study:
1) The R-value of Package F was found to be the highest. This means that it
is an effective insulator compared to the other packages tested. This container is made
of aluminum foil lamination, which makes it a convective and radiative barrier. The
R-values of Package A and B were comparable and were found to be better insulators

compared to that of Package C and E which are made of Thermal-Cor® material. The

 

EPS foam panels inside A and B seem to be more effective compared to the Thermal-
Cor® material.

2) The thermal analysis test of packages at both room and high temperatures with
dry ice and gel ice shows that the rate of heat transfer through Package F was
slower as compared to the other packages tested thus making it a better insulator.

3) As regards Box-in-Box packaging systems, the R-values of Packages H, I and J are
comparable because they have the same inside box surface areas. There was no
signiﬁcant difference found in the R-value of Packages H and J. The R-value of
Package I was found to be lower than that of the other two systems. Unlike in the
other two packages, where the inside box is aluminum foil laminated type, Package I
has a Thermal-Cor® inside box and aluminum foil laminated Thermal-Cor® is a
better insulator as compared to Thermal-Cor®.

4) The air inside the Box—in-Box packages seems to be acting as a good thermal
insulator. The melt rates in these packages were found to be lower as compared with

the single packages.

47

5) The R-value comparison tests should use all containers with the same inside
dimensions to provide relative performance of insulating properties based on the

method recommended by Burgess (1999).

48

 

8 BIBLIOGRAPHY

[1] Burgess, G. Practical Thermal Resistance and Ice Requirement Calculations for
Insulating Packages. Journal Of Packaging Technology and Science, 12:75-80, 1999

[2] ASHRAE Handbook Fundamentals, American Society of Heating, Refrigeration,
and Air-Conditioning Engineers, Inc, Atlanta, GA (1985)

[3] Incropera, P. Fundamentals of Heat and Mass transfer. New York: Wiley. (2002).
[4] Cold Ice Inc. (2003). httgzllwww.coldice.com/temperature indicatorshtml

[5] http://www.gﬁlacierbavcom/Heatpﬁroohtm

[6] Advantek Products.Vaculuk. (2003). http://www.advantek.com/vip content.htm

[7] Panyarjun, 0. Thermal Insulated Packaging Design with S-ﬂute Corrugated
Board. (2002)

[8] PRIMEDIA Business magazines & Media Inc. (2003).
http://www.wasteagecom/4arlwaste corrugated boxes 2/

[9] FedEx (2002). www.fedex.com
[10] HuntsMan Co. [2003]. http://www.huntsman.com/polymers/Media/th-Z.1.pdf

[11] Florida Chemical Company, Inc. (2003). http://wwwﬂoridgchemical.com/d-
limonenestyrofoamrecycling.htm

[12] International EPS Alliance. (2003). http://www.epsrecvclingorg/eps/index.html
[13] Alliance of Foam Packaging Recyclers. (2003). http://www.epspackaging.org1
[14] Corrugated Packaging Alliance. (2003). http://gpc.corrugatedorg/recvcle/

[15] Beaversplastics Inc. [2002]. www.be2_1versplgstics.com

[l6] Sensitech Inc. [2002].
htJt‘)://www.sensitech.com/Solutions/Instruments/e monitors.html#TT3

49

 

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