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This is to certify that the
thesis entitled

PERFORMANCE TESTING AND COMPARISON OF CLOSURES
FOR CORRUGATED SHIPPING CONTAINERS

presented by
PANKAJ GAUR

has been accepted towards fulfillment
of the requirements for the

MS. degree in Packaging

< gag/Q

Major ProfesW gnature
MM /0 20197

Date

 

MSU is an afflnnative-action, equal-opportunity employer

 

 

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:/ClRC/DateDue.indd-p.1

 

PERFORMANCE TESTING AND COMPARISON OF CLOSURES FOR
CORRUGATED SHIPPING CONTAINERS

By

Pankaj Gaur

A THESIS

Submitted to
Michigan State University
in partial fulfillment of requirements
for the degree of

MASTERS OF SCIENCE
School of Packaging

2007

ABSTRACT

PERFORMANCE TESTING AND COMPARISON OF CLOSURES FOR
CORRUGATED SHIPPING CONTAINERS

By
Pankaj Gaur

Corrugated boxes are the preferred shipping container of the 21St century.
For the past hundred years it has successfully replaced wooden boxes and
crates due to advantages like cost, ease of use, light-weight, and printability. At
present hot-melt adhesive, pressure sensitive tape and staples are used as
major box closures. There have been limited studies done to compare the
performance and integrity of corrugated fiberboard boxes as a function of closure
type.

This study compared the performance of existing closure systems
described above with a newly developed hot melt adhesive that is infra- red (IR)
cured. This new adhesive developed by National Starch Company is a solvent
free thermoplastic hot melt. Two different box sizes (small and large) with
packaged weights of 20 and 40 lb were drop and compression tested to
determine the closure integrity during handling respectively. Later was a newly
developed test for empty and closed samples of corrugated boxes. The results
showed that hot melt is better than both pre-applied adhesive and tape for both
large and small case sizes. Boxes with full flaps were found to be significantly
better than those with partial flaps. Adhesive failure percentage analysis shows
that pre-applied was better than hot melt for large full-flap boxes. The hot melt

adhesive showed the best performance for the larger sized and heavy boxes.

ACKNOWLEDGEMENTS

I would like to thank my advisor, Dr. Paul Singh, for all his support and guidance.
Dr. Singh’s high motivation and expectations inspired me to achieve beyond my
capabilities. Under his mentorship I gained exposure to numerous distribution
projects besides this thesis project. I would like to thank my committee members
Dr. Gary Burgess and Dr. Brain Fenny for their time and effort in the completion
of this work and were the source of invaluable advice through our engaging

discussions.

I am also grateful to the faculty and staff of School of Packaging, MSU. I am also
thankful to all my friends and fellow graduate students who have provided me the
wonderful friendly atmosphere throughout my Master’s program and research

penod.

Finally, I would also like to thank my parents for giving me immense support for
my higher education endeavor. They are the inspiration for making me what I am
and they will be the source of motivation for what I will be. The success of this

work belongs to them as much as anyone else.

iii

TABLE OF CONTENTS

LIST OF TABLES ................................................................................. vi
LIST OF FIGURES .............................................................................. vii
1.0 INTRODUCTION ............................................................................. 1
2.0 LITERATURE REVIEW ..................................................................... 4
3.0 MATERIALS AND METHODS ........................................................... 34
4.0 RESULTS AND DISCUSSION ........................................................... 43
5.0 CONCLUSIONS ............................................................................ 62
APPENDIX- TABLES ........................................................................... 63
REFERENCES .................................................................................. 109

iv

LIST OF TABLES

Table1. Characteristics of flute .............................................................. 10
Table2. Box Style and Dimensions ......................................................... 34
Table3. Box Lap Style and Closure Variables .......................................... 34
Table4. Box Code as a Function of Style and Closure Tested ................... 35
Table 5. Least square means for box size and adhesive type .................... 47
Table 6. Least square means for adhesive location and adhesive type ...... 48
Table 7. Least square means for flap style and adhesive length ................ 49
Table 8. Least square means for box size and adhesive length.................50
Table 9. Least square means for flap style and adhesive location ............. 51

Table 10. Least square means for box size and adhesive Iocation.............52
Table 11. Least square means for box size and flap style ......................... 53

Table 12. Drop test analysis ................................................................. 58

LIST OF FIGURES

Figure1. Corrugated Board Structures. ................................................... 5
Figure2. Commonly Used Corrugated Box Styles ................................... 12
Figure3. Half Flap Box Design .............................................................. 13
Figure4. Trend of global adhesive usage industry wise .......................... 15
Figure5. Trend of various adhesives in industry ..................................... 15
Figure6. Theory of Adhesion ............................................................... 16
Figure7. Classification of adhesive on chemical basis ............................ 18

Figure8. Classification of organic and silicon adhesive on basis of bonding

mechanism ........................................................................................ 19
Figure9. Different corrugated box stapling design .................................. 23
Figure10. Bulk Hot melt Applicator ........................................................ 25
Figure11. Hot melt nozzle Applicator ..................................................... 25
Figure12. Slot coat Applicator .............................................................. 26
Figure13.Tape Dispenser ..................................................................... 27
Figure14. Automatic case sealer .......................................................... 28
Figure15. Sheehan model of compression analysis ............................... 31
Figure16. Pre-Applied Glue .................................................................. 36
Figure17.Hot-Melt Glue ....................................................................... 36
Figure18. Pressure Sensitive Tape ....................................................... 36
Figure19. Small and Large Box ............................................................ 37
Figure20. Full Flap and Half Flap Boxes ................................................. 38
Figure21.Glue on comer of flap ........................................................... 38

vi

Figure22.Glue on mid flap ................................................................... 38

FigureZ3.Short Length of glue ............................................................. 38

Figure24. Lansmont Squeezer Compression Tester ............................... 39

Figure25. Normal Compression Test .................................................... 4O

Figur926. Diagonal Strength Test .......................................................... 40
Figure27. Lansmont PDT 56 Drop Tester ............................................... 42
Figure28. Box before Drop Test ............................................................ 42
Figure 29.Box after Drop Test ........................................................................ 42
Figure30. Failure Mode A, Delamination of fibers .................................... 43
Figure31. Failure Mode C, Adhesive Failure ............................................ 44
Figure32. Tear in Flaps ........................................................................ 44
Figure33. Tape Failure ......................................................................... 45
Figure34. Interaction between box size and adhesive type ....................... 47
Figure35. Interaction between adhesive location and adhesive type ......... 48
Figure 36. Interaction between flap style and adhesive length .................. 49

Figure37. Interaction between box size and adhesive length......................50

Figure38. Interaction between flap style and adhesive location ................ 51
Figure 39. Interaction between box size and adhesive location ................ 52
Figure 40. Interaction between box size and flap style ............................. 53
Figure41 Adhesive Failures in Large Box Size ....................................... 54
Figure 42 Adhesive Failures in Small Box .............................................. 55
Figure 43 Comparison of Adhesives within Large Boxes ........................ 56

Figure 44 Comparison Application method within Pre-Applied adhesive..56

vii

Figure 45 Comparison of Adhesive Length Pattern ................................. 56

Figure 46 Comparison of Adhesive location on Box Flap ........................ 57

viii

1.0 INTRODUCTION

1 .1 Boxes and Closures:

The US packaging industry has achieved great success in the terms of
performance and design. There have been various developments in both primary
and secondary packaging. Corrugated boxes form a major part of secondary
packaging and shipping containers. The closure for a box plays an important role
in maintaining the package integrity during the distribution and handling. Today a
wide range of corrugated boxes are used in different designs, styles and sizes. In
addition various adhesive types are available to secure boxes after they are
filled. The most commonly used boxed design is a Regular Slotted Container
(RSC). The most common box closure types are hot melt glues, pressure
sensitive tapes, and staples.

The corrugated industry is known to have existed as early as 1871, when
the first corrugated packing patent was given to Albert L. Jones. However some
developments occurred before this in England in 1856, when Edward Charles
Healy and Edward Ellis Allen were granted patent for the fluting of paper and
other materials, which is believed to have been used as sweatband lining in the
hats. The first double face patent was issued in 1874 to Oliver Long for his
invention of lined corrugated material for “Packing of Bottles, Jars & Containers”.
Long’s discovery laid the foundation for the corrugation box that is still being
used in the industry today. Soon after Oliver Long’s patent there was the public
disclosure of the double-faced board by Robert H. Thompson and he was

granted a patent for his invention in 1882.

Like the corrugated industry, adhesives for packaging industry are going
through continuous developments for bonding the liner to the fluting material. The
first adhesive known in the corrugated industry is cold starch paste, which had
high moisture content and used to take long time for drying, decreasing the
speed of the operation. But after World War I, there was a new adhesive
introduced called silicate clay starch, which had controlled penetration, and
required less heat for drying. This was longer lasting and had higher bond
resistance during variation of climatic conditions. In 1935 the industry switched
back to starch base adhesive that was formulated as a mixture of cooked and
uncooked starch as opposed to fully cooked starch used earlier. Sheehan in
1988 studied impact of closure type on the compression strength performance of
corrugated boxes. His work compared hot melt adhesives with tapes.

National Starch Company initiated this study. They developed a new Infra
Red (IR) activated adhesive. The objective of the study was to compare the
performance of the newly developed IR activated adhesive with previously know
box closure methods (pressure sensitive tape and hot melt adhesives). In
addition potential savings that could be realized by using IR activated adhesives
on short flap corrugated boxes as opposed to regular flap boxes that are required

for both tape and hot melt adhesives was investigated.

1.2 Objectives
The objectives of this study were:

- Compare performance of corrugated fiberboard container closure methods
(Newly developed IR activated adhesive versus existing hot-melt glues
and pressure sensitive plastic tape).

- Compare trends in closure performance as a function of box size.

- Compare trends in closure performance as a function of box flap size and
application pattern.

. Determine if the new closure method (IR activated hot melt) can provide

corrugated box material savings.

2.0 LITERATURE REVIEW

2.1 Corrugated Box Basics:

Corrugated board is commonly known as fiberboard or cardboard and the
terms are vague as it relates to Iightvveight paper based boxes used for a wide
range of products. Corrugated boxes are used for both secondary and tertiary
packaging throughout the world in the form of display cartons, shipping
containers, bulk boxes and pallets. This widely used material is both economical
and easy to convert and can offer a wide range of designs. It has been very

successful to create “transport packages” in the 20th century.

Corrugated industry shares almost 80% of the total paper based
packaging and represents nearly 50% of the total value in the United States
today. The corrugated box, also known as "brown box" is the most widely used
secondary package whose primary functions are to contain and transport the
primary packages to the retailer and consumers. In 2004 industry shipped
enough boxes to cover the entire states of Massachusetts, Connecticut and
Rhode Island put together. Therefore the overall economy in packaging depends
on the economics of corrugated box containers. An estimated $25bn of

corrugated material was sold in 2004 in the United States (CPC).

The ultimate selection of the shipping container is done based on product
protection and containment requirements and are a function of corrugated layers,

flute design, closure system, etc. It is important that the box closure system

selected provides the necessary package functions of containment and

protection.

2.1.1. Corrugated Board Structure:

The corrugated board is generally made of the two structural elements.
The first is the “liner" also called as facing and the second is “fluting” also called
as the corrugated medium. The design principle is similar to that of an
engineering beam concept. The two load bearing panels are separated by the
corrugated medium. The corrugated medium provides cushioning and strength to
the Iinerboard. Figure 1 shows the most commonly used paper corrugated board

single wall double-faced structure (Twede and Selke, 2005).

 

llner

 

double faced corrugated
single wall corrugated

 

 

 

 

Figure 1: Corrugated Board Structures

Source: Twede and Selke, 2005

2.1.2 Corrugated Board Materials:

Linerboard facings can be made from several types like fourdrinier kraft liners or
cylinder liners.

Eogrdrinier Kraft Qner: Fourdrinier is the name of the inventor of paper making
machine on which the liner is made, and “Kraft” is a German word meaning
strength. This term came up because liner was made from pinewood, which is
softwood and has long fibers giving high strength to the end product. This liner is
termed as virgin and has low recycled content. This type of paper manufacturing
is very common in United States and Canada.

Cylinder Liner: In most European and Asian countries due to a shortage of
softwood supply, the major source of liner is obtained from recycled US and
Canadian paper or from local hardwoods. The paper made with this fiber is not
as strong as that from softwoods. This type of paper is generally used to make
corrugated medium.

Paper used to make corrugated board is specified by “basis weight’. Basis
weight is important in corrugated industry as it standardizes the thickness.
Generally basis weight for linerboard in the US. is around 42 lbs (per 3000 ftz),
equivalent to around 16 points (0.016 in) in thickness, but there are various liner
materials available with variety of basis weights, ranging from 26 lbs to 90 lbs.
Corru_gated Medigm
The corrugated medium is a sandwich layer between the liner materials. Its
function is to provide stacking strength for boxes and cushioning to the contents

inside the box. It is also known as the “flute” and is normally made from recycled

softwoods or hardwoods. As it does not add any aesthetics to the corrugated
board it is generally made from unbleached pulp fiber. The corrugated medium is
the backbone of the board, and provides strength to the box and thus is normally
aligned along the height of the corrugated box in order to give it maximum
stacking strength and better compression resistance. Like liner materials, the
corrugated medium is also available in terms of its thickness. The normal
corrugated medium is typically 9 points (0.009 in) in thickness with a basis weight
of 26 lbs per 1000 ft2.

Depending upon the size and number of layers, the flute can be of several
types. Commonly available flutes are A, B, C, E, F and K, which vary in thickness

and number of flutes per unit length. This will be discussed later.

2.2 Corrugated board Industry:
Twede and Selke (1995) state, “The annual US production is more than
enough to cover 10,000 miles. The containerboard materials, called Iinerboard

and medium, comprise the highest volume single grade of paper made.”

The Fiber Box Association (FBA) is the governing body for the corrugated
industry in North America. It is a non-profit organization working for improvement
of overall well-being of the industry and provides a platform for its members to
conduct their business more responsibly and efficiently. The second major
organization is the Association of Independent Corrugators (AICC) and
represents over a thousand independent corrugated converting companies that

form corrugated shippers, display containers, signs and merchandising items

from corrugated fiberboard. There two major types of industry involved in the

corrugated Box Manufacturing.

Lam integrated producers: They are one stop manufactures of corrugated
boxes, as they manufacture from scratch that is making liner, corrugated medium
in'digenously making a corrugated board and then cutting it into blanks, printing
and then gluing the blanks to make final box. These companies with multi-billion
dollar sales include Smurfit Stone, Weyerhaeuser, Inland Corporation, Georgia

Pacific, International Paper, and Packaging Corporation of America.

Independent converters: They are partial manufacturer of the corrugated board,
as they get the corrugated board or liner and medium from the large paper
manufacturers. Then they cut the sheets, print and convert the material into

finished boxes for packaging.

2.3 Processes Involved in Corrugated Box Manufacturing

There are three major operation involved in the manufacturing of corrugated

boxes.

. Manufacture of the liner and flute medium.
. Joining (bonding) the liner and flute material together.

o Cutting, printing and gluing to make corrugated boxes.

2.4 Types of Corrugated Board

The corrugated board can be categorized into three variables:

2.4.1 Type of Face: Single and Double face

Single Face: When the liner is only on one side of the corrugated medium
then the board is called a single face board.
Double Face: The corrugated medium is sandwiched between two liner

layers and has two faces.

2.4.2 Number of walls: Single, double and Multi wall

Single wall: When there is only one corrugated medium and two liners
cover it from both sides, it is called single wall.

Double Wall: There are two corrugated medium and three liners. The liner
separates the two corrugated medium.

Multi Wall: Depending upon the usage requirement, the number of
corrugated mediums can be increased to as many as three and these
boards are known as multi-wall. Generally this kind of board is used for

large size pallet boxes, sidewall sleeves for bins, and corrugated pallets.

2.4.3 Flute Type:

Presently there are six’types of widely accepted flute designs used in the

corrugated industry. The standard size listed in order from largest to smallest is

A, C, B, E, F and N. Table 1 below shows the configuration basics of different

flute design (Selke & Twede).

Table 1. Characteristics of flute

«a».-- ....._‘ »--~.—.._

' I caaaiaéamf

 

Flute Type - Thickness (inches) Flutes per foot Take-up Factor
A 3/16 '_ 33i3 '. 154
B . -1/3w . -4112... . I 132
__C . ._.-......51.§?_.._-,-_._- 3‘ a -......§9..=l=.§._.__-.'4, -‘1-,4§.:_' '
-..E.- ‘ “mi/15.....- , V 9014 -_. 1--..1'217.“ T 2
I F " -1 99533,. -,-1.29-.=t.il- -, _, _ i  ’ Gil-523.". ' H r
'N 0.040 ' ? 170:5 1.15 _ ii

 

_.. -- mm“:- u... v.- ”-

 

2.5 Application of Corrugated Flutes in Packaging Industry:

A- Flute: This is the largest of all flutes; the purpose for its introduction was to
provide cushioning to fragile items like glass bottles and have higher stacking
strength. This is the oldest flute and most commonly used in Asia and Pacific

Region where the strength of paper is weak as compare to North America.

C- Flute: This flute was introduced for giving better flat crush properties, which
are usually required for the good printing qualities of the packages in printing

press. This is the most commonly used flute in North America.

B- Flute: This flute has intermediate effects of both Flute A and C, which means

that it will give good cushioning and satisfactory flat crush resistance.

E, F and N Flutes: They were introduced to compete with paperboard cartons for
fast food industry. The reason behind is the low thickness, which gives it fine
printing qualities and being a corrugated board it, gives better stacking and flat

crush resistance.

10

In multi wall corrugated boards, the flute selection plays an important role
by customizing package design. One can use thicker wall flute sizes A or C for
the inner corrugated medium and thinner one for the outer flute to give better
print impression. The most commonly used double wall flute used in the United

States is B-C flute.

2.6 Box Designs:

Box designs depend on the size and opening style of the container.
Currently there are six standard styles of boxes available in the corrugated
industry, which gives wide range for packaging applications for diverse industries
like food, chemical, pharmaceutical, health and beauty aids, electronics and
automotive, etc. This study was limited to slotted containers that use

glue/adhesive or tape closures to contain and secure product.

RSC (Regular Slotted container): This design is widely used in the industry
because of its low manufacturing cost and high strength. This design generates

less scrap as compared to other designs.

CSSC (Center special slotted container): This box has similar design to the RSC
except the flaps meet in the center of the box. As a result, this design requires

more corrugated board and also generates more waste.

OSC (Overlap Slotted Container): This name is self explanatory in which all the
flaps overlap each other providing more strength to the box. Generally this

design is used for long products where there is a probability of damage to outer

11

flaps due to small inner flaps in a RSC style container. The different RSC box

designs are shown in figure 2 (Fiber Box Association).

   

CSSC

 

OSC
Figure2. Commonly Used Corrugated Box Styles

Source: Fiber Box Association

Half Flap Container: This is a relatively new container and looks similar to RSC’s,
but has all the flaps of half the original size, and is open in the center of the box.
This box was developed for this study and provides corrugated board material
savings. This kind of box style can be used to unitize primary packages like

cartons and cans for cereals, soups, coffee, detergents, etc.

 

Flgure3. Half Flap Box Design

2.7 History of adhesives:

History provides many examples of adhesive usage by mankind in their
day-to-day life. The first example of adhesive usage is known to be 80,000 years
ago. when caveman used to make collages like decoration on skulls. Nature has
also given diverse examples of adhesive presence like those by honeybees for
nest building, which solidifies, as it gets cold. Animals like termites are also
believed to possess adhesive in form of sprays to incapacitate their enemies as
part of their defense mechanism.

In packaging, the first known adhesive is starch-based adhesive. In early
1900’s, the corrugated industry was known to use cold starch as the major type
of adhesive material. After World War I, sodium silicate adhesive was used
because of its resistance to climatic variation and good bonding. It is in 19503,
when corrugated cases and cartons were usually sealed using polyvinyl acetate
emulsion adhesives. After this hot melts were a major highlight in the packaging
industry. Hot Melt type of adhesives includes all synthetic hot melts. These were

widely accepted because of their fast setting time, good compatibility with waxes

13

and compatibility with difficult adhering surfaces. Hot Melt was introduced in bead
size for thin line application and mileage. Currently consumption of hot melts for
case and carton sealing is predicted around 266 million pounds for North
America and about 490 million pounds globally (www.pgrc.org) or Forsyth
2.9 Definition of Adhesive:
Adhesive for packaging is defined as an intermediate layer to seal or join two
layers of substrates. According to DIN EN 923 (Deutsches Institut for Normung e.
V) an adhesive is defined as:

. A non metal

. A binder that acts via adhesion or cohesion

3.2 Current Market Size of Adhesives: Today there are more than 1500
companies in US. manufacturing adhesives. In the packaging industry,
adhesives are widely used in corrugated board manufacture, carton side seams
and closures, manufacture of bags, labels, tapes and laminates etc. The US.
market for adhesives is estimated to be near $10 billion dollars, of which
construction and packaging industry share 80% of the total market share.
Corrugated boxes are the single largest product for adhesives followed by
pressure sensitive tapes and labels. Figure4 shows the trends of global adhesive
use (www.specialchem4adhesives.com). Figure 5 shows the market growth rate

of various types of adhesives used (www.specialchem4adhesives.com).

l4

Other Non Global
Disposables
Transportation 7
Flexible Packaging 5
Woodworking I
Sealants

l PSA

Construction

 

0 5 10 15 20 25

l

lConverting Packaging

l

l

l

‘ % Share of Market

Figure4. Trend of global adhesive usage industry wise

Technology Trend

 

Solvent Borne
Other
Water Borne

Reactive

Hot Melt

 

 

0.0 1.0 2.0 3.0 4.0 5.0
% Annual Growth Rate

 

Figure5. Trend of various adhesives In industry

Both Graphs Adapted from: www.sgecialchem4adhesives.com

15

2.10 Adhesion Theogy:

An adhesive bond can be described by the chemical structure of the
adhesive and can be a combination of the cohesion zone and the transition zone
(adhesive near the substrate layer). The adhesion zone and transition zone are
collectively called as bonding layer. Figure 6 describe the three zones and form

the basics about the theory of adhesion.

 

 

 

 

 

 

 

 

 

Adhesion
Zone
Cohesion
Zone Transition
Zone

 

 

 

 

2.10.1 Adhesion Zone: In this zone modification in the structure of adhesive
occurs due to molecular level interaction of the adhesive with the substrate layer.
The bond strength depends upon the interaction level. If the chemical bonding
(covalent, ionic, metallic or secondary bonding) is above 50% it results in high
bond strength. The bond strength also depends on “micro-mechanical adhesion".
This means that surface characteristics also play a critical role for effective
bonding. If the surface is rough or abrasive, it gives more room for the adhesive
to get into and results in a better bond strength. This function plays an important
role in the corrugation industry, as the corrugated medium and liner material are

rough. The most important factor for adhesive bonding is its moisture sensitivity.

Higher the moisture sensitivity of an adhesive, weaker is the bond strength over
a period of time. Good adhesion depends on wet ability of adhesive and
substrate layer.
2.10.2 Transition Zone: Here the chemical, physical and optical properties of
the adhesive vary depending on the thickness, which can fluctuate from
nanometers to a few millimeters. The thickness of this zone is decided by the
curing method used for drying the adhesive and substrate.
2.10.3 Cohesion Zone: The interaction of forces within adhesive molecules is
called cohesion. There are four sources of cohesion forces.

. Chemical force within adhesive polymer.

0 Forces generated by cross linking of polymer

. Secondary forces due to intermolecular interaction

0 Mechanical force between various constituents of adhesive.
The cohesion force is analyzed by the manufacturer and can also be verified by

curing mechanism.

2.11 Classification of Adhesives

Adhesives can be classified in two types based on:
2.11.1 Chemical Structure: The adhesive structure can vary depending upon
the source like organic compounds, inorganic and silicones. Also we can classify
them upon their performance as thermo-set, thermo-plastic and elastomers. The

materials, which cannot be re melted and used, are thermo sets and those, which

17

can are thermoplastics. Figure 7 shows the classification of adhesives

(www.feica.com).

 

. ._ Adheswes

   

 

 

I . I

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Organic . _ Inorganic
Compounds Silllcones Compounds
Ceramic
l 1 Materials, Metal
, .1 Oxides,
Natural Synthetic ,_ ‘ silicatee,
Materials Materials phosphates,
Proteins, Hydrocarbon , borate‘s
Carbohydrates, . + Oxygen; .' ,
Resins . Nitrogen, ’- '1 , _
' » Chlorine. Sulphur

 

 

 

Figure7. Classification of adhesive on chemical basis

Source: Bonding/Adhesive, Education Material by FEICA Fonds der Chemischen Industrie.
Frankfurt, in co-operation with the German Adhesives Association (lndustrieverband Klebstoffe),
Du$seldorf.

3.4.2 Curing Mechanism:

Adhesives can also be classified based on their curing mechanism. The first type
are called “physical hardening", where the adhesive is in the final state and does
not need any chemical reaction to get dry. They will dry with time, heat or
evaporation. Examples are hot melt, water based, and solvent based. The
second type is called chemically cured which require polymerization reaction like
addition or condensation to cure. These reactions some time also require an

external source to initiate or accelerate the reaction like radiation or anaerobic

activity. The figure 8 below explains the different types of curing mechanism and

adhesive type (www.feica.com).

 

Classification of organic adhesives and silicones
according to the bonding mechanism

 

    

Physically Hardening Chemically curing

Adhesives adhesives

0 Hot melts .. ‘ . Polymerization'adheswes ._ .

0 Wet Solvent adhesives ’ ' fir! Superglues: “ - ' '

0 Contact adhesives. - .,. Methyl methacrylates (MMA)

o Dispersion adhesives " . '- Radlatron curing adhesives

0 Water based adhesives ’

. Pressure sensitive Polycondensation adhesives
adhesives . Phenolic resins

o Plastisols - Silicones

o Polyamides

Polyaddition adhesives
. Epoxy resins
o Polyurethane

 

 

 

 

 

 

 

Figure8. Classification of organic and silicon adhesive on basis of bonding mechanism.

Source: Bonding/Adhesive, Education Material by FEICA Fonds der Chemischen lndustrie,
Frankfurt, in co-operation with the German Adhesives Association (lndustrieverband Klebstoffe).
Dasseldorf.

2.12 History of Adhesives in Packaging Industry

The main adhesive types used in packaging Industry are:
1) Hot Melt

2) Solvent Based Adhesive

3) Dispersion Adhesive

4) Pressure Sensitive Adhesive

2.12.1 Hot Melt:

There are many polymers which are used to manufacture hot melts like
copolymers of ethylene vinyl acetate (EVA), atactic polypropylene, mixture of
paraffin wax and polyolefin’s. They are volatile organic chemical (VOC) free so
there is no health hazard to humans. As they are 100% solid, they have very low
shnnkage.

Hot melts are generally supplied in the form of glue sticks or pellets which
are melted by a glue gun or nozzle, and spread over the material to be glued at
around 190°C. They also require pressing the two layers usually at room
temperature. In general, hot melt adhesives are less water sensitive than other
thermoplastic polymers, and are unaffected by water, moisture, or humidity.
However, if applied to a damp or wet surface, the bonding may be poor. Hot
melts can be formulated to increase their water sensitivity and are commonly

used for stamps, envelopes and paper products that are to be recycled.

Hot melt adhesives have some limitations, which must be acknowledged.
Hot melts do not hold good with heat sensitive substrates and adhesive bonds,
and lose strength at higher temperatures. They also lack chemical resistance.
Recently, new polyurethane hot melt adhesives are available which have good

heat resistance and cure and can be used with heat sensitive products.

2.12.2 Solvent Based Adhesive:
Solvent-based adhesives have 70-80% of solvent content. Their drying

mechanism is based on the drying of the solvent. As the solvent starts drying up

20

all the adhesive macromolecules starts coming close to each other building a
cohesive force. The major polymers used in its manufacturing solvent adhesives
are polymeric vinyl compounds, polymethyl methacrylate, natural and synthetic
rubber, etc. These adhesives are designated on the basis of minimum drying
time provided by the manufacturer. Drying and curing of solvent-based adhesives
rely largely on the method adopted to evaporate carrier fluids that cure the
adhesive. Around 90% of the carrier fluid must be evaporated during drying and
curing. This process of drying and curing these adhesives leads to longer
process times.
2.12.3 Dispersion Adhesives:

This adhesive has 40-70% of solid content and the rest is water. So as the
water dries due to evaporation the polymer molecules come together and form a
smooth layer giving good adhesion strength. The polymers used in these
adhesives are non-water soluble, vinyl acetate polymers and their combinations
with co-monomers, polyacrylates, etc. This adhesive needs curing at higher
temperatures to set the bond strength between the adhesive and substrate layer.
As these water-based adhesives are sensitive to moisture, they also lose their

bond integrity during high humidity conditions.

2.12.4 Pressure Sensitive Tapes:

Packaging tapes are the most widely used pressure sensitive adhesive
(PSA) tapes with global production in excess of 10 billion sq. meters per year.
They are primarily used as closures for corrugated boxes. Pressure sensitive

tapes are made up of two components, one is backing layer which can be paper,

21

cloth, plastic film or laminate, and the other is the pressure sensitive adhesive.
One or both of the sides of the backing may be specially treated to provide
controlled release or adhesion. Tape adheres to the substrate after pressure is
applied. The major types of pressure sensitive adhesives are based on the type
of natural and synthetic materials, including natural rubber, synthetic rubber,
block copolymers, acrylics, silicones, etc. These can be modified in various ways
through molecular weight selection, tackifier resin addition, oils, fillers, cross

linking agents, stabilizers, pigments and other additives.

The most commonly used PSA tapes used in packaging are made with
polypropylene, polyester and polyvinyl chloride based backing. These films are
normally formed by extrusion and do not require the use of solvents. Therefore
the environmental concerns related to film manufacturing are also minimal. The
strength of bonding of PSA tape to the substrate depends on the type of
substrate used, as each substrate has different surface energy and the one that

has the least surface energy will fail early.

2.12.5 Adhesive Alternates in Packaging Industry

The two most commonly used alternates to adhesive based closures for

corrugated boxes are staples and bands/straps.

2.12.6 Staples:

Staples are generally made of metal. A stapling machine punches a metal piece,

which pierces the two materials and thereby is bent and joins the two substrates.

22

Staples are easily separated and can be recycled and take 1/40 the space as
compared to tape. Stapling is good for packaging large and heavy items for long
distance shipping with thick packaging materials. They also hold well during
adverse weather and environmental conditions. A stapled box is always a safe

package, whether damp, dusty, hot or cold.

The following illustration10 show the most efficient method of stapling the
tops and bottoms of corrugated boxes. Note that the number of staples required

in each case depends on several factors, including board quality, contents, and

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

staple type etc.
Light Duty Normal
\ K
I l
l l I l I l I I
l l I l l I
1 I l 1 I l l I
l l I l
k; /
Heavy

 

 

 

Figure 9. Different corrugated box stapling design.

Source: httpzllwww.greatlittleboxcomlpack101_tips_closure.php

23

The disadvantage of staples is that they hinder the process of corrugated
recycling as they can choke the equipment. They also reduce the reusability of

the box as they puncture the corrugated board thereby reducing its strength.

2.13 Application Techniques:
2.13.1 Hot Melt Application:

The term Hot— Melt is self explanatory, meaning that the adhesive will melt
on application of heat. There are several different types of equipment available in
the packaging industry depending upon the application. They range from manual
application like a heat gun to automatic applicators for bulk usage. In the hot gun
the adhesive (Hot melt) is used in the form of glue sticks that fits in the heating
gun. The gun has a small nozzle opening from where the melt adhesive is
delivered.

There are many processes for automatic hot melt applicators like
Extrusion, Swirl Spray, Fiberized Dispersion, and Contact Coating. Heated
applicator heads process low to medium viscosity thermoplastic hot melts. These
choices offer application of the adhesive in many different patterns. The bulk hot
melt applicators have a head consisting of a heated body, a number of gluing
modules or jetting elements, and a nozzle or coating die. Generally a filter is
used for the heated adhesive supply hose and applicator head. This simple and
often overlooked step will improve system operation by limiting downtime due to
adhesive charring and foreign material contamination. Figure 10 shows a BULK

hot melt applicator.

24

 

Figure10. Bulk Hot melt Applicator

Source: www.nordson.com

In addition different types of outlet designs can be used based on the pattern of
the adhesive required. The one common example is a nozzle applicator shown in

figure 11.

 

Figure11. Hot melt nozzle Applicator

Source: httpzllwww. itwdynatec.com/mr1 300.htm

2.13.2 Slot Die Coater
The slot die coater is a relatively new method of applying the adhesives

without using rollers. The adhesive is pumped into a chamber, where it exits

25

through a long narrow slot, directly in contact with a moving substrate. The
substrate is usually supported immediately behind the slot with a rubber or steel-

backing roll as shown in Figure 12 (http://www.specialchem4adhesives.com).

 

Figure12. Slot coat applicator
Source:www.shure-glue.com

The slot die coating method is inherently low foaming, and is capable of
producing good quality material at high line speeds. However, the equipment is
relatively expensive and requires a high level of operator expertise. Moderate to

high coat weights are possible with slot die.

Multiple Microscopic Bead (MMB), is a new technology developed by
National Starch Adhesives for coating solvent free adhesive. In this case the
multiple beads are extruded in a very close space. IR activated adhesives used
in this study were solvent free thermoplastic hot melts.

2.14 Closure Applicator for Tapes:
Tapes are applied both manually and automatically using different types of

applicators.

26

2.14.1 Tape Dispenser:

This is used for manual application of tapes on the corrugated boxes. This is
good for offices and small packinghouses. This is most common method of
applying pressure sensitive tapes on corrugated boxes. Figure 14 shows

commonly used tape dispensers.

 

Figure13. Tape Dispenser

Source: http://multimedia.mmm.com/mws/

2.14.2 Automatic Case Sealers:
Cases can be automatically folded and sealed using these case sealers.
This process is used in fast and efficient manufacturing facilities. These
machines are flexible and can be set for different box sizes and designs (Figure

14).

27

 

Figure14. Automatic case sealer

Source: www.okcorp.com/groductslSemiAutomaticCaseSealers

2.15 Compression Testing:

Manufacturers in the past used to evaluate the strength of boxes by
simulating rough handling at their own facilities. But these were temporary
arrangements without any fixed standards. As the majority of the damage
observed was due to long-term stacking of boxes, compression testing became
an area of interest in the industry. Malcolmson in 1936 figured out that
compression strength of the empty container is an indication of their ability to
protect the product inside the box during shipping and handling. Later in 1940,
Grundy reported a program for corrugated board use and testing the
performance of empty boxes for compression strength. Balkema. who also
worked with Grundy published compression test standards in 1949 -1950. These

standards were represented in a graphical form between the box compression

28

and perimeter of the flute size and combined board grades. The graph also
provided a correction factor for different conditions like humidity, box size and
printing coverage. McKee and Gander (1957) did a qualitative description of top
load compression behavior of boxes in terms of its structural components and
generated the widely used McKee’s equation used to predict the compression

strength of corrugated boxes.

2.16 Previous Studies on Performance of Boxes and Closures:

Boxes and closures are partners in performance (Sheehan 1988).
Selection of an appropriate closure type is critical for the shipper and carrier.
There are numerous parameters like cost, material, waste generated and
equipment that play a role when selecting the adhesive and that can comply with
shipping regulations required to pass performance testing.

All box closure materials are generally compared on the basis of their
physical properties. When comparing performance of similar boxes with different
closures or adhesives in a lab environment, it is easy to predict difference in
performance on the basis of physical properties like adhesion and tensile
strength. But when comparing the same two adhesives in a real life application
and use, additional variables can influence the results. During shipping, all the
components of the box like the liner and flute, closure components like adhesive,
backing, undergo stresses and the entire system combination has to meet the

challenges.

29

The most widely used method to judge performance of corrugated boxes
is to test the compression strength of empty boxes. Sheehan (1988) compared
the performance of closures (tape versus hot melt adhesives) using compression
testing of empty boxes. In this study he used two sizes of boxes. Box A was an
RSC and measured 12 x 12 x 12 inches. Box B was also an RSC and measured
18 x 12 x 12. The top to bottom compression tests was performed using ASTM
642 with both fixed and floating platens. The experiment was a factorial design of
23 meaning there are two levels with three different factors. Since small
differences can give a difference in the results, a large number of samples were
tested to prove that the results were statistically significant. After the data was
collected, it was analyzed using analysis of variance (ANOVA). Results showed
that Box A size performed better than the Box B and fixed platen gave better
results than floating platen. He also concluded that the tape closure was better
than the hot melt coating tested. Sheehan also added that in this test there was
very low or negligible effect of the closure system on compression strength
results as the vertical walls, comers and edges were the main supporting points

in the compression test. Figure 15 shows a summary of the results.

30

Glue

Floati

 

Figure 15. Sheehan model of compression analysis
Sheehan further analyzed the results with a control box that was closed but no
closure was applied and compared its performance with the two types tested
before. The results were very astonishing as he found that boxes without any

closure system performed better as compared to tape and adhesive closures.

Sheehan performed a second set of tests using Full Overlap Containers (FOL)
that are stacked on their panels and the flutes run parallel to the panels. These
style containers rely on the full flaps that have vertical flutes for stacking strength.
In this study he tested six closure types:

0 Two-inch wide crown staple perpendicular to the flute.

- Two-inch wide crown staple parallel to the flute direction.

31

. One bead of hot melt on the flaps.
0 Hot melt adhesive covering 90% of the flap area.
. Two L-clip of 1/ 2 inches P-S filament tape.

a Two L-clip of 1/ 2 inches P—S filament tape with different flap pattern.

In this study he calculated the F10 value (the force required for 10% of the
boxes). He found that staples parallel to the flute performed better than the
staples perpendicular to the flute. It was also observed that there was a statistical
difference in the closure performance based on tape closure and flap pattern. In
the case of hot melt adhesive, 90% of the laminated closures out performed all
other types of closures and was way better than single beads of adhesive, The
single bead was acting as a point for stress concentration and resulted in
damaging the box. The final results of his studies concluded that there is
significant effect of the closure system on box performance for the shipping
environment.

There are 24 million packages shipped in the single parcel service
environment in today’s environment with the major carriers (UPS, FedEx, DHL,
and USPS) according to Bacior (2006). Closure/containment is an important
function to insure packages are shipped without damage. FedEx estimates about
40% of loss and damage problems attributed to failure of the closure system.
Bacior (2006) showed three parameters to analyze tape closure failure: Tack,

Peel and Shear. The H-configuration tape closure has been found to be the best

32

performer for packages in the single parcel environment based on actual field
observations.

This study was funded by National Starch Company to compare the
performance of three types of box closures. The tests were developed to
compare performance of to existing box closure methods: tape and hot melt
adhesives to a newly developed IR activated adhesive. The advantage of the
new IR activated adhesive is that boxes with partial flaps can be closed on
automatic box sealing equipment. This can result in reduced corrugated use and
result in cost savings. In addition the study used two different test methods to
compare the performance. One tested the diagonal compression strength of the
empty container that stressed the closure till failure. The second method was a
series of drop tests with dummy products (sand bags) till closure failure or loss of

contents.

33

3.0 Materials and Methods

This chapter describes the different materials and test methods used for
performance evaluation of the closures used on boxes in this study.
3.1 Materials Used:

There were thirty types of box and closure combination samples that were
used in this study. These samples varied in box size, design, adhesive type and
adhesive location pattern. All boxes were single wall RSC containers and made
from C flute with an edge crush test (ECT) value of 32 Ib/in. Table 2 shows the
box type and dimensions used in this study. Table 3 describes the various
closure and box style test variables. Table 4 shows the box code used for test
results and describes the specific designs, closure types, and application
methods tested. The missing cells for box codes in Table 4 represent the sample
styles that were not of interest to the sponsoring company (National Starch &

Chemical Company) and were not practical.

Table 2: Box Style and Dimensions

 

Table 3: Box Lap Style and Closure Variables

 

 

 

 

Small Full Middle Short Extrusion Pre-Applied 40
Large Partial Corner Long Sloat Coat Std. Hot Melt 20
MMB Tape

 

 

 

 

 

 

 

 

34

Table 4: Box Code as a Function of Style and Closure Tested

 

 

 

 

 

 

* White rows samples were not provided for this study.

35

The boxes tested can be classified in four different ways:
3.1.1 Based on the Closure System Used:

Three closure systems; hot-melt, pre—applied glue (a National Starch's
patented product) and pressure sensitive tapes were analyzed. Out of the
total 30 box combinations, 18 box designs were closed using an IR activated
pre—applied glue, 12 with hot-melt glue, and 2 with tape. The reason for only
two tape designs was that variables like half flap, location and pattern were
not possible using tape closures. Figure 16 shows a sample box with the new

IR activated pre-applied glue. Figure 17 and 18 show sample boxes with hot

melt and tape closures.

 

Figure16. Pro-Applied Glue Figure 17.Hot-Melt Glue

 

Figure18. Pressure Sensitive Tape

36

3.1.2 Based on Size and Weight of Box:

Two box sizes large (12" x 16" x 10") and small (8 3/8" x 8 1A" x 6 W) were
tested. In this study with 30 box designs, 17 boxes were large, and the
remaining 13 were small. The larger boxes were filled with a dummy weight
(sand bags) of 40 lb and the smaller bags were filled with 20 lb for the drop

test performance. Figure 19 shows the large and small box size.

 

Flgure19. Small and Large Box

3.1.3 Based on Flap design:
Two box styles with different designs were used. The first style was a
conventional full-flap box, and the other is a half-flap design that results in
corrugated board material savings. Out of 30 boxes tested,18 had full flaps

and 12 had half flaps. Figure 20 shows boxes with full and half flaps.

37

    

Figure20: Full Flap and Half Flap Boxes

3.1.4 Based on Glue Pattern and Location (Corner or Mid Flap): The glue
pattern and location can also be used to describe the boxes tested using the hot
melt adhesives. There were two types of glue patterns used on the corrugated
boxes; one on the corner of the box flaps (Figure 21) and the other on the middle

of the flap (Figure 22).

 

Figure 21: Glue on comer of flap Figure 22: Glue on mid flap

    

I

Figure 23: Short Length of glue

38

3.2 Test Methods:

Two different test methods were used for testing the performance of the
three closure systems on the various box sizes and styles. These are discussed
in the next section.

3.2.1 Compression Strength Testing:

In packaging, corrugated box requirement range from appearance (aesthetic
looks) to the mechanical strength to protect the product inside. The box during
shipment faces diverse dynamic environment like rough handling, shock and
vibration stacking of boxes. This makes the performance test of the corrugated
board really important. To simulate all the condition in the laboratory gets really
tough. Therefore the compression strength of the empty box is widely accepted
under ASTM D 642 for the calculation of the stacking strength of the box. Not
only compression test helps in stacking strength but also it helps to analyze
overall strength of the box. There is also one disadvantage in compression test,
that it cannot predict the cause of box failure (is it due to component of box,
manufacturing process, adhesive or converting). Therefore Industry has stressed
to make a direct relationship between in these individual factors and compression

strength.

 

Figure24. Lansmont’s Squeezer Compression Tester

39

 

2

3

4

 

    

1) Boxes are kept straight on the

v

V

V

Normal Compression Test

Figure25. Normal Compression Test

1)

faces between the two platens.

The Platens can be fixed or
floating. But it is specified that for
corner configuration only fixed
platen will be used.

2)

The ASTM 642 says to use 50 3)
lbs as preload for single wall
container and 100 lbs for double

wall.

4

V

Yield is not specified so it is
taken as per test condition.

 

Diagonal Strength Test

   

  

ML.
1 vs},

Figure26. Diagonal StrenhgtTest

The boxes were kept in a
configuration with the edges
between the platens with the flaps
facing towards us.

The platens were tested in fixed
configuration.

The configuration is very sensitive
to the glue applied and different
design of the boxes. So the
preload of 10 lbs was used.

For this testing yield of 50% was
selected. So test was performed
till there is 50% reduction in load
applied.

 

40

 

3.2.3 Test Set Up:

The machine used is Lansmont squeezer with fixed platen. All the tests were
done in conditioned room with 77 F and 50 RH. The machine was calibrated at
10 lbs preload to clear the deformities in the height and yield point was set as
50%. For each type of box 20 samples were tested for the compression testing.
The key factors in this test were the Maximum force, Minimum force, Standard
Deviation and deformation. To keep the consistency plumb Line was used to

check that the diagonal of the box is at perfect edges and parallel to thread.

3.3.1 Drop Testing: -

The drop testing is an old technique to evaluate a product's performance during
distribution handling. So drop test can be also helpful to know the performance of
the adhesives during manual handling. Drop test is the second test used to check
the strength of the adhesive. The main role for doing this test was to check the

real-time functioning of the flap.

The entire drop tests were done according to ASTM D 5276 98 using Lansmont

PDT 56 ED, Precision drop tester. The maximum drop height and weight it can

take is 72 and 150 Lbs respectively on a standard platen.

41

 

Flgure27. Lansmont PDT 56, Drop Tester

3.3.2Test Setup:

All the boxes were stuffed with the sand bag, which were then rolled with bubble
wrap for shock absorption. This test was done according to ASTM 5276, where
the height for 20 lbs box was given as 30 inches and height of 40le boxes is 24
inches. For each sample 5 boxes were tested. Further each box was dropped
repeatedly until the flap fails. Normally we could not find many impressive results

in this test as in maximum cases the box failed at first drop. The failure criteria of

flap were same as for compression testing.

 

F igure28. Box before Drop Test Figure29.Box after Drop Test

42

4.0 RESULTS AND DISCUSSION

This chapter discusses the data collected and the results obtained. The boxes
and closures tested were manually inspected for failure. Five different categories
of failure modes were developed and are individually explained in the next
section.
4.1.1 Failure Mode A: De-Iamination of the Fibers

This failure mode is often the most desired failure by the adhesive
manufacturers. From adhesive manufacturer’s point of view, the bonding
between the adhesive and box fiber should be higher than the bonding between
the cohesive forces of fibers of the corrugated box. This type of failure mode is

shown in Figure 30.

 

Figure30. Failure Mode A, Delamination of fibers

4.1.2 Failure Mode B: Adhesive Failure
This is the most important factor for closing of the flaps on a box. Poor

adhesives can lead to opening of the flaps even at low forces, and result in

43

spillage of the contents. So the box with minimum adhesive failure will give better

real-life performance. Figure 31 shows this type of failure.

 

Flgure31. Fallure Mode C. Adhesive Failure

4.1.3 Failure mode C (Tear in the flap): This is also an important factor for
deciding strength of the adhesive layer, because adhesive area should be so
strong that it should not fell part, and the box failed due tears in the middle or
side of the flaps and adhesive area remain intact. As we know always the low
strength area fails so in this case the failure is due to again poor corrugated

board.

    

Figure 32. Tear in Flaps

4.1.4 Failure factor D (No failure even at 50% yield): This mode is also very
important for the adhesive manufacture as well as corrugation manufacture
industry as the strength of both will help to give strength to the final corrugated
box to sustain actual force. So it is given 20% of total percentage for rank
determination.

4.1.4 Failure mode E (Uncovering of the tape): This is taken into consideration
because we were having two samples of the boxes (small and large) with tape-
closed flaps. In these boxes the uncovering of the tape was the only deciding
factor found. Also as it was having very number I have given very low percentage

to it.

    

Figure33. Tape Failure

45

4.2 DISCUSSION
The two tests performed for the measurement of closure efficiency were
compression test and the drop test. So the analysis is done on the basis of two.
Compression test results
In compression test two parameters were very important, one is the compression
force and second is the failure type. So for the compression test data is analyzed
in two processes.

. On the basis of the compression force required for the batch design.

0 Percentage of adhesive failure on the total failure modes.
4.2.1) Compression data analysis on the basis of the compression force: In
this project the samples were provided by half factorial design. So it was
analyzed using SAS programming at SCC (Statistical consulting center) in Crop
and Soil Resource department. In this analysis we were only able to study the
two-way interaction between the variables due to some of missing samples. In
two-way interaction there were 7 significant combinations for the analysis of box-
closure system. These combinations are as follows:
a) Large —Small box size with Hot Melt- Pre-Applied adhesive.
b) Corner-Mid flap adhesive location with Hot Melt- Pre-applied adhesive.
0) Full - Half flap box with Long- Short adhesive pattern.
(I) Large and Small box size with Long- Short adhesive pattern.
e) Full - Half flap box with corner and mid flap adhesive location.
f) Large and Small box size with Corner and Midflap adhesive location.

9) Large and small box size with Full and Half Flap design.

46

a) Large —Small box size with Hot Melt- Pre-Applied adhesive:

The graph shown below that there was not much difference between the glue
variables (Hot-melt and Pre-applied) for the large box size but for the small box
design, there was significant difference observed. The Hot-melt small box did
better than Pre-applied small box. The vast difference between hot melt and pre-

applied in small box size can be explained due missing half flap hot melt boxes.

All the half flap boxes took less compression force as comparison to full flap.

00
N

 

 

  
    

g—I— Pre—Applied T 35

 

 

 

 

 

 

 

31.5 + Hot Melt _ §
8 L.—~.—e~~..;e “L, were 30 o
I h
0 31 u— .
l “- 25 S .
.5 30.5 ~ } g .
g 30 ‘ 20 g
. '5. 29.5 — E .
o
l E 29 _ 15 o
I ° ._
, o o
1 “5 28.5 r 10 2 .
. m
l 1% 28 * 5 a
g 27.5 ~ " g
m
LIJ 27 0
Large Box Small Box
Figure.34 Interaction between box size and adhesive type
Table 5. Least square means for box size and adhesive type
Least Squares Means
Standard I
Effect A F Estimate Error DF t Value Pr > |t|
A*F Large Hot-Melt 31.3506 0.8154 524 38.45 <.0001
A*F Large Pre-Applied 31.1255 0.8087 524 38.49 ‘ <.0001
A*F Small 1 Hot-Melt 28.6849 1.7783 524 I 16.13 1 <.0001
A*F Small LPre-Applied 23.6219 0.7830 524 1 30.17 I<.0001

 

 

 

 

 

 

 

 

 

 

 

 

47

 

Q)_Adhesive on Comer-Mid flap; Hot Melt and Pre-applied adhesive variable:

Looking at the graph below, we can say that Hot-Melt adhesive performed better
than pre-applied on the midflap location of the boxes. But on the other side pre-
applied performed better than hot melt on the corner location of the box. By this
reulst we can infer that midflap was good for hot melt and corner location was

better for pre-applied.

 

 

 

c 32 32 a,
0 0
.2 31 31 .2 ‘
.5 30 .5
g‘ 29 28 g
0 U
‘5 28 27 s
s 26 a
E 27 25 E
A 26 . ‘ _ 24 3
Hot Melt Pre-Applied

Figure35. Interaction between adhesive location and adhesive type

Table 6. Least square means for adhesive location and adhesive type

 

Least Squares Means

 

Standard
Effect c F Estimate Error DF tVaIue Pr>|tI

c*F Corner Hot-Melt 29.0250 1.2338 524 23.53 <.0001

 

 

 

c*F Corner Pre-Applied 28.2931 0.7830 524 36.131<.0001

 

c*F Mid-flap Hot-Melt 31.0105 1.1808 524 26.26 ‘<.0001

 

 

 

 

 

 

 

 

 

c*F Mid-flap Pre-Applied 26.4542 0.8087 524 32.711<.0001

 

48

c) Box with Full and Half flap; Adhesive pattern long- short:
The figure below explains that there long adhesive pattern was better than short
for the full flaps. And in both the cases the full flap was significantly better than

the half flap boxes.

 

10'
5

10
-.- .~ 5

  

7 :I—iLong , 1

e 50 ' - V “l—o—ShortI"~ 50
9 45 . . CW __ .1 _ 45 g
“9 40 40 9
C c
.9 35 35 .Q
3 a
e 30 30 9
Q.
g 25 25 g
o 20 20 o
'9 15 15 .91
“5 (u
E .E
175 773'
“J u.l

 

Full Flap Ha” Flap

 

Figure 36. Interaction between flap style and adhesive length

Table 7. Least square means for flap style and adhesive length

 

Least Squares Means

 

1 Standard 1
Effect B l D Estimate Error DF tVaIue 1 Pr>1t1

I

B*D Full ‘Short 36.3939‘ 0.7964 524 45.70 <.0001
B*D Full Long 43.2494 0.7830 524 55.23 <.0001

13*1) Half Short 17.1203 1.1808 524 14.50 <.0001
13*!) Half Long 18.0187 1.2329 524 14.62 <.0001

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

d) Large and small box size; Adhesive pattern long- short
Graph below states that there was significant decrease in the compressive force

for the long length of adhesive with the box size. Large box with long length was

49

found to be the best combination. For the short length of adhesive there was no

difference observed with the change of box size.

 

40'

35

30 30

Estimate of compression force

 

25 25

20 20

15

10

Estimate of Compression Force

 

U1

5

 

 

0
Large Box

 

~ 0
Small Box

Flgure37. Interaction between box size and adhesive length.

Table 8. Least square means for box size and adhesive length.

 

Least Squares Means

 

I

Standard 1
Effect A D Estimate Error DF tVaIue ; Pr>1t|

A*D Large Short 26.85701 0.7964 1524 33.721<.0001

 

 

 

 

 

A*D Large long I 35.61901 0.8278 5241 43.703 I<.0001
A*D Small Short 26.6577 1 1.1808 5245 22.58 <.0001
A*D Small1 Long 25.6491 1 1.1914 5241 21.53 <.0001

 

 

 

 

 

 

 

 

 

 

 

e) Box with Full and Half flap; Adhesive location on corner and midflap
The figure below explains that there was no difference found in the pattern of flap

design with change of adhesive location. The full flap box design performed

50

better in both the adhesive location compare to half flap design. Also there was

no significant difference observed with the adhesive location within full or half flap

 

 
     
 

 

 

 

 

design.
17 7 * 7 7 7 7 *‘+* Cornér W
45 . . ~J—Q—Mid Fla l- 45
I” p .. o
J 8 40 - PW 1» 4o 8 .
I L1. 35 ' ‘ - 35 LL
‘ .5 30 30 .5
g 25 g 25 g
E- 20 20 '5.
o 15 15 g
Q 10 » 10 U
E 5 5 E I.
1 Full Flap Half Flap
Figure38. Interaction between flap style and adhesive location
Table 9. Least square means for flap style and adhesive location
Least Squares Means
I I Standard
Effect 1 B C Estimate Error DF t Value Pr > 1t|

 

B*c Full Comer 40.9794 0.7830 524 52.33 <.0001
B*c Full Mid-flap 38.6639 0.7964 5247754855 <.0001
B*c Half Comer 16.3388 1.2338 524 13.24 1 <.00015
B*c Half Mid-flap 18.8008 1.1807 524 15.92 1 <.0001

 

 

 

 

 

 

 

 

 

 

 

 

 

f) Large and small box size; Adhesive location on corner and midflap

The graph below shows that there was significant difference between large and
small box size with the corner adhesive location. Corner location was found to be
higher for the large boxes; this can be explained due to the distance between the

force applied and adhesive location. For mid flap the adhesive was far away from

51

 

the compression platen and hence took less force by torque principle. But the
mid flap adhesive location there is very small difference observed between the

compressive for box sizes.

I -l— I 7 7 corner

 

 

    

 

 

. 35 ._._ -_ 35

1 5 30 , . - , ' 30.9

I C .

l .2 25 » ‘ ’ ' 25 '3

I 3 . g
a 20 . ' 20 o.
o 15 ' 15 o
'6 ‘5
o 1 — I”

1 a, 0 10,2,
in" m

0 - 0

Large BOX Small Box

Figure 39. Interaction between box size and adhesive location

Table 10. Least square means for box size and adhesive location

 

Least Squares Means

Standard
Effect A C Estimate Error. DF tVaIue Pr>|t1

A*c Large Comer 33.1203 0.8084 524 40.97 <.0001
A*c Large Mid-flap 29.3558 0.8165 524 35.95 <.0001
A*c Small Comer 24.1978 1.1914 524 20.31 <.0001

A*c Small Mid-flap 28.1090 1.1808 15241 23.81 1<.0001

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

9) Large and small box size; with full and Half Flap design
From the figure below we can inference that full flap boxes performed way better
than the half flap boxes despite box size i.e. is large or small. In full flap design

the large size box was better than a small size box. In the half flap design there

52

was no difference observed in the compression strength with the change in box

size.

50 1 1 j..." VFuIIFIapL 50

 

 

Estimate of Compression force

 

Estimate of Compression force

 

 

1 Large Box Small Box

 

Figure 40. Interaction between box size and flap style.

Table 11. Least square means for box size and flap style.

 

Least Squares Means

Standard
Effect A B Estimate Error DF tVaIue Pr>|t|

A*B Large Full 44.3864 07964 524 55.73 <.0001
A*B Large Half 18.0897 0.8278 524’ 21.85 <.0001
A*B Small iFull 353569 0.7830 5241 45.03 1<.0001!
A*B Small Half 17.0499 1.7783 5241 9.59 1<.0001

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

4.2.2. Analysis on the Basis of Adhesive Failure:
Here the analysis was done by only considering the main effect and ignoring the
interaction between the various variables. As closure system was important

variable for this project, so percentage of adhesive failure was taken into account

53

for analysis. Critical combinations were studied and average of the adhesive
failures.

a) If we look at the plot below, we can see that in the large boxes, Hot Melt
observed least adhesive failure and tape was the worst closure system having

maximum adhesive failure.

100
90
80 *
7O -
60

 

 

Adhesive Failure %
01
O

 

   

 

PRE-APPLIED HOT MELT . TAPE
Figure41 Adhesive Failures in Large Box Size
b) The graph below for small boxes explains similar adhesive failure pattern
among the three adhesives as shown by large boxes. Hot melt was the best
among three closures systems. Although here as well tape closure was found
with maximum adhesive failure, but it was better than large size boxes. This
trend is also supported by drop data where small taped box performed better

than large tape box.

54

 

Adhesive Failure %
0|
0

    

l PRE-APPLIED HOT MELT

Figure 42 Adhesive Failure in Small Box

0) The chart below shows that pre-applied adhesive found lower adhesive failure
than hot melt adhesive in large full flap boxes. Whereas in case of large half flap

boxes hot melt was better.

 

20 Half Flap 1

  
 

Full Flap Half Flap

   

Adhesive Failure %

 

 

I PRE-APPLIED HOT MELT

Figure 43 Comparison of Adhesives within Large Boxes

55

d) In the graph below is shown the comparison of two types of application
method used for pre-applied adhesive on the corrugated boxes. The slot coat

was better application method as it gave less adhesive failure.

 

Adhesive Failure %

 

 

 

Slot Coat

MMB

Figure 44 Comparison of Application method within Pro-Applied adhesive

e) In the figure below, we can see comparison of adhesive length pattern on
basis of adhesive failure percentage. The Short adhesive pattern was found to be
better than long adhesive pattern. This can explained on the basis of force
required per unit of adhesive length. 80 in the small length pattern, the force

required was more and thus lower adhesive failure.
17 7- 77 7 _7-77

1 25

 

20
15
10

Adhesive Failure %

 

 

 

 

Figure 45 Comparison of Adhesive Length Pattern

56

f) Comparison of adhesive location is shown below. There were two adhesive
locations selected for this study, one at comer and other at mid flap of the box
flaps. The Corner location observed lower adhesive failure as comparison to mid—
flap. This can be explained on principle of torque. Torque is rotational force
measured in Newton-meter. The longer the distance lesser the force is required
to move the object. Here midflap is farther than corner location from the platen
(acting force). 80 for corner higher force was applied resulting in better adhesive
strength.

1 .7 7 7
Adhesive Location Pattern

 

Adhesive Failure %

 

 

 

Midflap Corner

Figure 46 Comparison of Adhesive location on Box Flap

57

4.3 Analysis of Drop Test Results

In drop testing we did a drop test for 5 samples for each design and each box
was dropped repeatedly till failure. $0 for 5 samples numbers of drops were
recorded and were analyzed for adhesive closure system.

The below table shows all the box configuration which took more than 5 drops in

total for 5 samples.

 

 

 

 

 

 

 

 

 

 

 

Table 12. Drop test analysis :-
Ngmbeg Of Fagtges 4m 5‘" T t l GI :
o a . ue .
Type drop drop drop drop drop Drops Box Deslgn Location ;
SF-33 2 3 23 Small Box Tape
FL-16 3 2 12 Large Full Hot Melt Corner
FL-32 1 2 11 Large Full Pro-Applied Corner I
FL-08 2 1 1 9 Large Full Pre-Applied Corner 1—
HMF-10 1 4 9 Large Half Hot Melt Mid Flap
LF-34 2 3 8 Large Tape
HL-14 3 2 7 Large Half Pre-Applied Corner
MFL-11 4 1 6 Small Full Hot Melt Mid Flap

 

 

 

 

 

 

 

 

 

 

 

Looking at the table above we can say that small box with tape took maximum
number of drops for 5 boxes and was contradicting with the compression data
results. This trend is also supported by adhesive failure percentage data where
there was less failure as compare to large box with tape.

By analyzing the table we also can say that hot melt adhesive took more number
of drops for Large Half and Full flap boxes as compare to pre-applied adhesive.
The comer location was found to be better than midflap, as there were 4 boxes
with having adhesives on corner location as compare to only one in case of
midflap.

Summary of Key Findings:

58

Compression force data shows:

— No Significant difference observed between the Hot melt and Pre-
applied (IR) for large size box.

— In small case size Hot melt was better than Pre-applied.

— For hot-Melt adhesive midflap was better location than corner flap.

— Full flap was significantly better than the half flap boxes.

— Significant difference between large and small box size with comer
flap adhesive location.

— Long adhesive length gave higher compression strength than small

for large box.

Adhesive Failure data:-

— Tape was found to have maximum adhesive failure.

— For Large Full Flap boxes Pre-applied was found to better than Hot-
Melt.

— For Half Flap box design, more failures were observed in Pre-
applied as compare to Hot Melt.

— Short adhesive length was better than long length in terms of
adhesive failure.

— Slot coat was found to be better application method as compare to
MMB.

— Comer flap location found less adhesive failure as comparison to

Mid Flap.

59

Drop testing results shows
— Small box with tape withstood maximum number of drops before
failure.
— Large hot melt boxes were better than pre-applied for both full and
half flap design.

— Corner flap location for adhesive application was found to be better

than mid-flap.

. Box Design: Half Flap box is a promising design for Packaging Industry as

it reduces corrugated cost.
. The new closure strength test does not correlate with drop test results.

- Additional testing on other box sizes, weights and closures needs to be

done.

5.0 CONCLUSIONS
This study reached the following conclusions based on the different materials
and boxes tested:
1. The tape closures show the best closure performance for containment of

products during drops followed by hot melt adhesives and IR activated

adhesives.

2. The newly developed IR activated adhesive can provide corrugated

material savings between 5 to 10%.

6O

 

. The new test method measuring compression strength of an empty
corrugated box with closure in a diagonal configuration does not show

correlation with performance testing based on edge drop tests.

. The boxes with large flap showed better results than half flaps.

61

Appendix

62

Compression Testing Results

A.1 Data 8. Figure of HL-2

 

 

 

Force:

Deviation:
IFAILURETYPEI A | B 1 c I D l E I F I
|PERCENTAGEI 65 1 20 1 5 1 1o 1 1 |

 

to
to

to tear
not at

 

63

A.2 Data & Figure of FS-03

 

 

FAILURE
TYPE E F

 

 

 

 

 

 

 

 

 

to tear
at

 

64

A.3 Data & Figure of FMFS-4

 

65

A.4 Data & Figure of FS-05

 

 

 

FAILURE
TYPE A B C D E F
PERCENTAGE 70 20 10

 

 

 

 

 

 

 

 

t0

 

66

A.5 Data & Figure of HS-06

ype
Peak load failure
7

5.7

 

 

 
    

 

FAILURE
TYPE A B C D E F
PERCENTAGE 80 5 10 5

 

 

 

 

 

 

 

 

 

 

67

A.6 Data & Figure of PCS-07

   

 

 

FAILURE
TYPE A B C D E F
E

PERCENTAG 90 5 5

 

 

 

 

 

 

 

 

to
to

 

68

A.7 Data & Figure of FL-08

 

 

FAILURE
TYPE A B C D E F
PERCENTAGE 80 20

 

 

 

 

 

 

 

 

 

to
to

to tear
not at

 

69

A.8 Data & Figure of HS-09

HS-9

ype
Peak load failure

 

 

 

PERCENTAG 30 40 10 20

 

FAILURE
TYPE A B C D E F
E

 

 

 

 

 

 

 

 

70

A.9 Data & Figure of HMF-10

HMF-10

 

 

 

 

 

 

 

FAILURE
TYPE A B C D E F
PERCENTAGE 25 35 40

 

 

 

to
to

to tear
not at

 

71

 

A.10 Data 8: Figure of MFL-11

 

 

 

 

 

 

 

FAILURE
TYPE A B C D E F
PERCENTAGE 85 15

 

 

 

 

to
to

 

72

A.11 Data & Figure of FL-12

 

 

     

 

 

FAILURE
TYPE A B C D E
PERCENTAGE 65 20 15

 

 

 

 

 

 

 

 

to

 

73

A.12 Data & Figure of HL-14

HL-14

Peak load

 

 

 

 

FAILURE
TYPE A B C D E
PERCENTAGE 45 30 20

to
to

 

 

 

 

 

U'I'TI

 

 

 

74

A.13 Data & Figure of FS-15

FS-15

ype
Peak load failure

 

 

FAILURE
TYPE A B C D E F
PERCENTAGE 25 55 10 10

 

 

 

 

 

 

 

 

 

to
to

 

75

A.14 Data 8. Figure of FL-16

ype
Peak load failure

 

 

 

 

 

 

 

FAILURE
TYPE A B C D E F
PERCENTAGEI 60 40

 

 

 

 

to
to

 

76

A.15 Data & Figure of HS-17

 

 

 

 

 

 

FAILURE
TYPE A B C D E F
PERCENTAGE 55 45

 

 

 

 

 

to
to

 

77

A.16 Data & Figure of MFS-18

MFS-18

YPe
S.no. Peak load failure
1

 

 

 

 

 

 

 

FAILURE
TYPE A B c p E F
PERCENTAGEI 80 20

 

 

 

 

to
to

 

78

A.17 Data & Figure of FMF-19

FMF-19

Peak load

 

 

 

 

FAILURE
TYPE A B C E F
PERCENTAGE 75 20

to

 

 

 

UIU

 

 

 

 

to

to tear
not at
uncovered

 

79

A.18 Data & Figure of FL-20

ype
S.no. Peak load failure
1

3

5

 

 

 

 

 

 

 

 

 

FAILURE
TYPE A B C D E F
PERCENTAGE 61.11 38.89

 

 

 

to
to

to tear
not at

 

80

A.19 Data 8: Figure of HL-22

HL-22

Peak load

 

 

 

IFAILURETYPEI A I B I c 1 D I E 1 fl
[fERCENTAGEI 50 1 35 I | 5 | 1 1T]

 

to

to tear

not at

 

81

A.20 Data & Figure of FS-23

ype
Peak load failure

A

 

 

 

FAILURE
TYPE A B C D E F
PERCENTAGE 100

 

 

 

 

 

 

 

 

 

to
to

 

82

A.21 Data 8: Figure of FMF-24

ype
failure

 

 

     
 

 

 

 

 

 

FAILURE
TYPE A B C D E F
PERCENTAGE 65 5 30

 

 

 

 

to

to tear
not at

 

83

A.22 Data & Figure of HL-26

HL-26

YPe
Peak load failure

 

 

 

 

FAILURE
TYPE A B C D E F
PERCENTAGE 38.46 23.07 7.69 30.76

to

 

 

 

 

 

 

 

not

 

84

A.23 Data 8. Figure of FS-27

ype
failure

 

 

 

 

FAILURE
TYPE A B C D E F
PERCENTAGE 30 65 5

 

 

 

 

 

 

 

to
to

to tear
not at
uncovered

 

85

A.24 Data & Figure of FMFL-28

FMFL-28

Peak load

 

 

 

 

 

 

 

 

 

 

 

FAILURE
TYPE A B C D E F
PERCENTAGE 60 40
WHERE

to
to
to

at

 

86

A.25 Data 8. Figure of HS-29

HS-29

Peak load

 

 

FAILURE
TYPE A B C D E F
PERCENTAGE 30 1O 35 25

 

 

 

 

 

 

 

 

 

 

87

A.26 Data & Figure of HL-30

HL-30

ype
S.no. Peak load failure

 

 

 

 

FAILURE
TYPE A B C D E F
PERCENTAGE 25 50 8.33 16.67

 

 

 

 

 

 

 

to
to
to tear

not at

 

88

A.27 Data & Figure of FCL-31

FCL-31

ype
Peak load failure

 

 

FAILURE
TYPE A B C D E F
PERCENTAGE 6O 20 10 10

 

 

 

 

 

 

 

 

 

 

89

A.28 Data & Figure of FL-32

FL-32

S.no. Peak load

 

 

 

 

 

FAILURE
TYPE A B C D E F
PERCENTAGE 55 5 20 20
I

 

 

 

 

 

 

 

to
to

to tear
not at

 

90

A.29 Data & Figure of SF-33

Peak load

 

 

FAILURE
TYPE A B C D E F

 

 

 

 

 

 

 

PERCENTAGE 50 45 5

 

 

to
to

 

91

A.30 Data 8: Figure of LF-34

LF-34

ype
Peak load failure

 

 

 

FAILURE
TYPE A B C D E F
PERCENTAGE 45 5 50

 

 

 

 

 

 

 

 

 

 

92

1)

2)

 

 

Drop Testing Results

3.1 Data & Figure of HL-2

 

Results of the Drop Testing

    

Hl—2 before drop After drop

82 Data & Figure of FS-03

 

    

Fs-03 before drop I ‘ aft drop

93

 

3)

4)

    

3.3 Data & Figure of FMFS-4

 

    

»‘o_:,"

F mfs-O4 before drop Afterdrop

3.4 Data & Figure of FS-05

 

Hs-05 Before drop After drop

94

3.5 Data 8. Figure of HS-06

5)

 

      

Hs-06 before drop r drop

3.6 Data & Figure of PCS-07
6)

 

         

FCS 07 before drop After drop

95

 

3.7 Data & Figure of FL-08

7)

 

      

Fl-8 before drop After drop

8.8 Data & Figure of HS-09

 

96

3.9 Data & Figure of HMF-10

 

  

 

Hmf—1 0 before drop

3.10 Data & Figure of MFL-11

MfI-11 before drop After drop

97

3.11 Data & Figure of FL-12

11)

    

Fl-12beforedrop If ‘ Afterdrop

8.12 Data & Figure of HL-14

12)

 

      

HI-14 before drop After drop

98

B.13Data & Figure of FS-15

  
    

 

Fs-15 before drop After drop

3.14 Data & Figure of FL-16

F L-1 6 before drop After drop

99

3.15 Data & Figure of HS-17

of

 

      

HS—17 before drop V I After rop

8.16 Data & Figure of MFS-18
16)

 

         

MFS-18 before drop M After drop

100

3.17 Data & Figure of FMF-19

    

FMF-19 before drop After drop

3.18 Data & Figure of FL-20

 

      

Fl-20 Before drop After drop

101

3.19 Data & Figure of HL-22

19)

 

       

 

HL-22 before drop After drop

3.20 Data & Figure of FS-23
20)

. FS-23 before drop After drop

102

3.21 Data 8. Figure of FMF-24

 

         

FMF-24 before drop After drop

B22 There were no samples left for the HL-26 for drop testing.

103

8.23 Data 8- Figure of FS-27

23)

 

      

meI-BB Before drop After drop

3.24 Data & Figure of FMFL-28

 

      

Fmfl-28 Before drop 9 A drop

104

3.25 Data & Figure of HS-29

25)

 

      

Hs-29 Before drop Aftr drop

8.26 Data & Figure of HL-30

 

      

HL-3O before drop after drop

105

3.27 Data & Figure of FCL-31

27)

 

  

   

FOL-31 before drop Afterrop

3.28 Data & Figure of FL-32
28)

Fl-32 before drop After drop

106

3.29 Data & Figure of SF-33

29)

 

  

   

SF-33 before drop After drop

3.30 Data & Figure of LF-34

LF-34 before drop After drop I

107

 

WHERE

 

Due to delamination of fibers

 

Due to adhesive failure

 

Due to tear in flap

 

Did not failed at 50% yield.

 

Tape uncovered and flap open

 

 

Fail below preload

 

'nrnUOCD>

 

108

 

9.

5.0 REFERENCES

. George G. Maltenfort, Performance and evaluation of shipping containers,

Jelmar Publications Inc, 1989.

George G. Maltenfort, Corrugated Shipping containers- An engineering
approach, Jelmar Publications Inc, April 1990.

Diana Twede and Susan E.M. Selke, Handbook of paper and wood
packaging technologY; DEStech Publications, Lancaster, Pa., USA
02005.

Edited by Frank Kreith and Yogi Goswami; The CRC Handbook of
Mechanical Engineering, Chapter 12, Materials- Adhesives by Lehman
Richard L.

Malcolmson, J.D. The Value of the compression test for corrugated boxes.
Fiber Containers 21, no. 4:14, 16 (April, 1936)

Grundy, A.V. Engineering aspects of corrugated container purchasing.
Fiber Container 25, no. 7:16, 20-1 (July, 1940).

Edward M. Petrie, Handbook of Adhesives and sealants, McGraw-Hill,
2000

Pizzi & Mittal, Handbook of Adhesive Technology, Marcel
dekker,lnc.,2003

www.specialchem4adhesivescom assessed on 27th April 2006.

10.Schaepe. M, The influence of pin adhesion on edge crush and box

compression strength, Corrugating lnt., vol. 2, no. 2, Apr. 2000, pp 35-39

11.http://www.pprc.org/pubs/techreviews/hotmelt/ assessed on 15th April 27,

2006.

12.This “Educational Materials” series textbook entitled “Bonding/Adhesives”.

13. Forsyth, RS; Packaging and case and carton hot melts: fifty years of

change and progress, 2001 Hot melt symposium, Hilton Head Island, SC,
USA, 10-13 June 2001, 14pp [Atlanta, GA, USA: TAPPI Press, 2001.

14.Sheehan, RL; Box and Closure: Partners in performance; Journal of

Packaging Technology; v-2, no.4; 1988

109

15. Bacior L. Michael, Package Closure/Containment Analysis; Dimensions
Conference 2006.

16. Brody Marsh, The Wily Encyclopedia of Packaging Technology second
edition 1997.

110

 

     

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