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(0515290520

This is to certify that the
thesis entitled

CORRUGATED CUSHION VS EPS: A COMPARISON OF
CUSHION PROPERTIES

presented by
JOONGMIN SHIN

has been accepted towards fulfillment
of the requirements for the

MS degree in PACKAGING

 

90M {banal/(IQ

M'ajor Professor’s Signature

SEPTEMBER 30, 2004

 

Date

MSU is an Affirmative Action/Equal Opportunity Institution

 

 

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

Ibalfil‘ 1 2 an?

gel 7‘2008

 

 

 

 

 

 

 

 

 

 

 

 

 

 

6/01 c:/ClRC/DateDue.p65-p.15

 

 

CORRUGATED CUSHION VS. EPS; A COMPARSION OF CUSHION PROPERTIES
BY

JOONGMIN SHIN

A THESIS
Submitted to
MICHIGAN STATE UNIVERSITY
in partial fulfilment of the requirements
for the degree of
MASTER OF SCIENCE
SCHOOL OF PACKAGING

2004

ABSTRACT

CORRUGATED CUSHION VS. EPS; A COMPARSION OF CUSHIONPROPERTIES
BY

J OONGMIN SHIN

Cushioning systems, which are cushion material and its designed configuration, are
important to protect fragile items since they act as buffers between the impact force and
the fragile product. As cushion materials, several plastic foams are commonly used in
industry. Among plastic cushion materials, EPS is the oldest synthetic and the most
widely used cushion material with a multitude of applications with various advantages. It
is utilized for a variety of products, which require a careful protection such as consumer
electronics and furniture. However, utilization of the material has been causing a solid
waste problem and pollution. Thus, as an alternative cushion material to EPS, a
corrugated cushion, which is considered environmentally friendly and cheap material,
was put into drop tests and, and its impact shock attenuation was investigated. Two types
of a corrugated cushion were constructed, “flat crush mode” and “edge crush mode”. Flat
and free fall drop data were recorded and compared to the dynamic shock of EPS cushion.
In addition, the published cushion curves and corrugated cushion design formulas were
compared to the actual shock G. For laboratory parts, a cushion tester, free drop tester,
and EDR were used to evaluate their overall cushion properties.

The results show that the corrugated cushion gives an excellent protection for
items that are subjected to the limited number of drops. Also, there is a potentiality to

improve its cushion properties through changing its designs.

Copyright by
.Ioongmin Shin
2004

ACKNOWLEDGEMENTS

I would like to express my deepest heartfelt thanks to Dr. Gary Burgess, my
advisors, for their educational and professional guidance and advice. I could not

successfully complete this research project without all his support.

I also would like to express my sincere appreciation to my committee members.
Dr. Paul Singh and Dr. Brain Feeny. Their valuable advice helped to complete this

research project.

I also thank to lnstrumented Sensor technology Inc. The company support

Environmental Data Recorder and kind advice for this research project.

I would like to express my appreciation to all the faculty and staff of the school of
packaging, all my friends, and all those who helped me in one way and another during the

course of my graduate studies.

Finally, my deepest appreciation goes to my family, my father Mr. Shin, Euljai,
mother Ms. Kim, Kihee, and sister Shin, Jeeyoung who supported me though the difficult

times and the good times while accomplishing my education.

TABLE OF CONTENTS

Page

LIST OF TABLE .............................................................................................................. viii
LIST OF FIGURE .............................................................................................................. ix

CHAPTER I

INTRODUCTION ............................................................................................................... 1

CHAPTER 2

LISTERATURE REVIEW .................................................................................................. 5
2.] “Edge Crush Test” and “Flat Crush Test” on corrugated board .................................... 5

2.2 Corrugated cushion design formulas ............................................................................ 8

2.3 Humidity effects ........................................................................................................... 12
2.4 The Environmental Data Recorder (EDR) ................................................................... l3
CHAPTER 3

MATERIALS AND EXPERIMENTAL DESIGN ............................................................ I5
3.I Verification of EPS cushion curves ............................................................................. IS
3.2 Corrugated board cushions .......................................................................................... 2|

3.3 Comparison between EPS and corrugated board cushions .......................................... 28
CHAPTER 4

RESULTS AND DISCUSSION ........................................................................................ 33
4. I. Verification of cushion curves .................................................................................... 33
4.2. Shock transmission vs. the number of layers .............................................................. 35
4.3. Shock transmission vs. layer arrangement .................................................................. 38

V

4.4. Shock transmission of edge crush mode (ECT) cushions ........................................... 45

4.5. Evaluation of prediction formulas .............................................................................. 48
4.6. Corrugated vs. EPS cushions ...................................................................................... 50
CHAPTER 5

CONCLUSIONS ................................................................................................................ 52
APPENDIX ........................................................................................................................ 54

vi

LIST OF TABLES

Table Page
I. Corrugate board strength vs relative humidity (RH) .................................................... I2
2. Gate times vs free fall drop height ................................................................................. 20

3. Predicted shock transmission value vs. actual shock transmission value at I8 and 30

inches ................................................................................................................................. 33
4. Shock transmission value vs. number of layers ............................................................. 35
5. Peak acceleration of flat crush cushions in three different arrangements ...................... 39
6. Dynamic deflection of flat crush cushions in three different arrangements .................. 40
7. Peak G’s for edge crush mode cushion ......................................................................... 45
8. Predicted G’s vs. Actual G’s .......................................................................................... 48
9. Corrugated vs. EPS cushion ........................................................................................... 50

vii

LIST OF FIGURES

Figure Page

1. Edge Crush Test .......................................................................................................... 6
2. Flat Crush test ............................................................................................................. 7
3. Environmental Data Recorder .................................................................................. l4
4. A shock pulse record from corrugated cushion ........................................................ l6
5. Dynamic Cushion Tester for Drop test ..................................................................... I8
6. Mis-aligned flute cushion ......................................................................................... 24
7. Perpendicular flute cushion ....................................................................................... 25
8. Aligned flute cushion ................................................................................................ 26
9. Identification of number for surface of the package-EDR3C system ....................... 29
IO. Analyzed shock pulse from software ........................................................................ 3|
1 I . Shock transmission values vs. number of layers ...................................................... 36
I2. Shock 0’5 and dynamic deflections of corrugated cushions in three

I3.

I4.

l5.

arrangements. (Drop height=l 8”, Static stress=0.2 psi) .......................................... 4|
Shock 0’3 and dynamic deflections of corrugated cushions in three
arrangements. (Drop height=| 8”, Static stress=0.5psi) ........................................... 42
Shock 0’5 and dynamic deflections of corrugated cushions in three
arrangements. (Drop height=l 8”, Static stress=0.8 psi) .......................................... 43

Shock transmission of edge crush mode cushions .................................................... 46

viii

CHAPTER I. INTRODUCTION

Cushioning systems (cushion material and its designed configuration) are
incorporated in package-product systems to protect fi‘agile items. When a package is
dropped on a rigid surface, the cushion system which is contained in the package acts as a
buffer between the impact force and the fragile product. The product does not stop as
abruptly as the outer container impacts the ground. The cushion allows it to slow down
gradually [I]. Therefore, cushioning systems are important to protect fragile products in
distribution. For cushioning materials, there are several plastic fabricated foams that are
widely used in industry; Expanded Polystylene (EPS), Polypropylene foam, Polyethylene
foam, and Urethane foam. EPS is considered the standard cushioning material used in
consumer product applications, and represents the baseline against which the other
materials are compared [2]. Among plastic cushion materials, EPS is the oldest synthetic
and the most widely used cushion material with a multitude of applications, since it is
light weight, has a high strength to weight ratio, and low moisture absorption properties.
EPS is utilized for a variety of products which require protection, like consumer
electronics, furniture, and so on. However, the solid waste problem with EPS makes its
utilization a concern. Moreover, environmentally friendly materials are being supported
by the government in terms of recycling laws.

The environmentally friendly cushioning material, corrugated board, was
introduced in the early 1950’s. Corrugated board has three layers of paper assembled
using a series of arches, which gives it compression resistance and reasonable rigidity to
support heavy weights. This structure provides an almost unlimited combination of board

types, flute sizes, weights, adhesive types, coatings, and so on. One easy way to make

corrugated cushions from corrugated board is to attach each layer using glue. In this
research, two types of cushions were constructed; the “flat crush mode” and the “edge
crush mode”. For the same size cushion, the edge crush mode can support heavier
products, but the flat crush mode, and the flat crush mode gives lower G values compared
to the edge crush mode.

Con'ugated board can be a very useful cushion material. It is environmentally
friendly with an unbeatable record for recycling and recovery as well as economical cost.
However, corrugated cushions tend to produce higher shock levels than EPS as the
number of drops increases because the mode of deformation is one of crushing
(permanent deformation) rather than elastic compression and recovery as with foam
cushions. Moisture sensitivity is another problem. Since paper is susceptible to moisture
gain, corrugated cushions lose their resilience and elasticity at high relative humidity
conditions. Corrugated cushions will also be too brittle in extremely low relative
humidity conditions. Finally, as a marketing issue, consumer perception is a problem.
People think a corrugated cushion is usually used for cheap products because it is a cheap
material. Therefore, the use of corrugated board as a cushion has been limited, and has
been neglected in research aimed at evaluating corrugated board as a cushion. Through
this study, corrugated cushions will be compared as a cushioning material to EPS, and
will be evaluated for their shock transmission properties. Conventional cushion curves for
EPS and design formulas for corrugated cushions will be tested for their accuracy and

ability to produce effective cushions. The detailed objectives of this study are as follows:

|. Check the accuracy of published cushion curves for EPS.

The published shock transmission characteristics (ASTM D-I 596) of EPS cushion
may not be accurate. Some are more than IO years old before they are checked
again. Material composition may change over this long time. Using the cushion
tests, the actual shock transmission characteristics will be evaluated and compared
to the published curves.

2. Design and test corrugated fiberboard cushions

- Evaluate the accuracy of corrugated cushion design formulas.
The cushioning characteristics of corrugated cushions can be estimated using
simple design formulas for the number of useful drops, the dynamic shock G, and
the dynamic deflection. However, there has been no recent research to verify
these design formulas. This study will evaluate the accuracy of corrugated
cushion design formulas.

- Recovery properties of corrugated cushions.
EPS is used by many consumer product manufacturers because of its multiple-
impact protective properties. Corrugated cushions are not regarded as being
resilient, losing all of their cushioning properties after several drops. Its lack of
resilience makes it perceived as a cheap packaging material. However, there is
still the possibility that corrugated cushions retain enough resilience to be useful.

-Comparison of dynamic shock G values for different alignments of the flutes in

corrugated cushions.
Corrugated fiberboard cushions will be constructed of layers having their flutes

oriented three different ways; aligned parallel flutes, perpendicular parallel flutes,

and misaligned flutes. The G values from each will be measured and compared to
each other.
3. Compare cushioning performance between EPS and corrugated cushions, with actual
product in drop tests.
Impact G value is one of the most important parameters used to estimate cushion
properties. An impact data recorder packaged in both EPS and corrugated

cushions will be used to compare the two.

CHAPTER 2. LITERATURE REVIEW

2.! “Edge Crush Test” and “Flat Crush Test” on corrugated boafl

The edge crush test (ECT) measures the edgewise compressive strength, parallel
to the flutes, of a short column of corrugated board. According to TAPPI T 402[ref], the
edge crush test is performed as in Figure l. The edgewise compression resistance of
corrugated board is used to estimate box compression strength. The flat crush test (FCT)
is a measure of the ability of the corrugated board to resist being crushed under the action
of a compressive force perpendicular to the surface. Figure 2 shows the test procedure for
measuring flat crush resistance. The flat crush strength is critically important to
corrugated board because it is closely related to the strength of the fluted medium. A
stronger medium gives a higher flat crush strength. This reduces crushing during
conversion and product use [5]. The strength of the medium however decreases with

multiple drops.

 

 

LOAD

 

 

 

 

 

SAMPLE

 

 

 

 

 

 

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Figure l: Edge Crush Test

 

 

 

 

 

 

Figure 2: Flat Crush test

 

2.2 Corrugafted cushion design formulas

There is not much published on corrugated board used as a cushioning material.
Consequently, there are no widely used cushion curves to predict shock transmission
characteristics for the material. However, through several formulas, it is possible to
estimate the shock G value without them. To estimate the G value, we need a measure of
the resistance to compression. This is provided by both the ECT and FCT values for the
board. When medium in layer balance along with newton’s law, the resulting design

equations are:

 

G =EE-T-f—L if edge crush mode, or
G =E—Tié if flat crush mode (l.l)
. . 17
Dynamic deflection=—(-;- (l.2)
Shock duration=—l- & (l.3)
G \l g
Number of useful drops = Cushion thickness (l.4)

dynamic deflection

The ECT and FCT values along with the cushion geometry (length or area) and product
weight (wt) provide enough information about the material to determine G in any

situation involving flat drops onto cushions operating in the edge crush and flat crush

modes respectively. The formulas are derived by using Newton’s second law, which

states that:

F = W x G (l.5)
F =peak impact force on the product

W = weight of the product

G = peak acceleration of the product expressed as a multiple of gravity, g

g = acceleration due to gravity = 386.4 in/sec2

So G can be determined from:
F

G = — 1.6
W ( )

Newton’s third law states that the force exerted by the corrugated cushion on the product
is equal in magnitude and opposite in direction to the force exerted by the product on the
cushion. In the edge cushion mode, the force on the cushion acts to crush it. In the

process of crushing it, this force is:
F: ECT (lb/in) x L (in) (l .7)

Where L means “edge length” for a cushion. It is the total length of edge the falling
weight acts upon. For example, a ten layer edge crush cushion where each layer has a
length of 2.5” would have a total edge length of 25 inch.

Through Newton’s first and second laws, equation (I .6) becomes:
9

ECT(lb / in) x L(in)
W(Ib)

 

Edge crush G = (I .8)

The same method is used to derive the flat crush G. The reaction force is given by:
F= FCT (lb/inz) x A (inz) (1.9)
where A is the area of board the falling weight acts upon. For example, a ten layer flat

crush cushion where each layer measures 2” x 3” has an area of 6 inz.

Substitution into equation (l.6) yields:

FCT(psi) x Area(in2)
product weight(lb)

 

Flat crush G: (|.l0)

Formula (l .10) shows that in the flat crush mode, only the bearing area is needed to
estimate the peak G in a drop. No matter how many layers are in a flat crush cushion, the
peak G is predicted to be independent of the number of layers.

If a corrugated cushion “bottoms out” after several drops, the predictions are
invalid. This can be determined by evaluating the dynamic deflection in a drop. In order
to calculate dynamic deflection, the following energy balance is manipulated:

potential energy= weight x drop height = force x dynamic compression.

l0

The force is the same as before: ECT x L for an edge crush cushion and FCT x A for a

flat crush also.

Wh Wk 11
Dynamic deflection = 7:".— = W; : 5. (H l)

Substituting the forces from equations (L7) and (1.9) gives:

 

 

. . _ W(lb) x h(in)

Dynamic deflection (for ECT mode) E CT x L (in) (l.l2)
. . _ W(lb) x h(in)

Dynamic deflection (for FCT mode) FCT x A (in 2) (l . l 3)

If the force required to crush corrugate board remains relatively constant, as the board
cushiones, a relatively constant acceleration should be experienced by the falling weight.
Thus, the allowable number of drops can be predicted by calculating the dynamic
deflection in each drop using equation (l.l2) and (I . l 3) and treating this as a permanent
deflection. The cushion bottoms out when these deflection accumulate to the thickness of

the cushion. Dividing the thickness by this amount:

Cushion thickness
The number of useful drops= , , (|.l4)
dynamic deflection

 

ll

This assumes that the dynamic deflection is a permanent deflection. Equations (HO) and
(1.13) predict that the number of layers has no effect on the flat crush G or its dynamic
deflection, but it does affect the number of useful drops because the thickness depends

on the number of layers.

2.3 Humidity effects

The performance of corrugated board depends on humidity conditions.

As humidity increases, the board gets weaker. The following Table | shows the
relationship between strength at a reference humidity of 50% RH and the strength at any
other relative humidity. At 85% RH for example, a box is only 60% as strong as at 50%
RH. Since box compression strength is proportional to the ECT of the board used to make
it, this means that the ECT of the board is only 60% of its value under that conditions of

50% RH.

 

 

 

 

 

 

RH Percent strength retained
0% l25 %
25% 1 IO %
50% 100 %
75% 8O %
85% 6O %
90% 50 %

 

 

 

 

Table l. Corrugate board strength vs relative humidity (RH)

I2

Humidity affects the performance of con'ugated cushions the same way. The ECT and
FCT are adjusted using the same strength retention factors. According to equations l.8 &
1.10, the G values should also be adjusted by the same account. So the peak G at % RH
should be 60% of the peak G at 50% RH. The G goes down because the cushion is softer.
This is good. But the dynamic deflection increases proportionally giving fewer useful

drops.

2.4 The Environmental_Da_ta Recorder (EDR)

The “Environmental Data Recorder” is a portable data recording system for making
dynamic field measurements. Using the EDR lets us measure what actually happens in a
drop. This sensor records shock pulses using a tri-axial accelerometer. It records G in the
X, Y, and Z directions. The unit itself and the three shock pulses are shown in Figure 3.
The unit records three shock pulses for every drop and later combines this information to
arrive at the drop height and other relevant information through the use of software.
These recorders are packaged in rugged aluminum housings for use in harsh
environments, and engineered for high shock and vibration survivability while fully

operable over a large temperature range.

l3

 

Figure 3. Environmental Data Recorder

CHAPTER 3. MATERIALS AND EXPERMENTAL DESIGN

3. I. verification of EPS cushion curves

Traditionally, packaging engineers design cushions by combination knowledge of a
product’s fragility level, and weight, and dynamic cushioning curves for the cushion
material. Through the cushion curves, they can establish guidelines within which an
effective cushioning configuration must be developed. However, established cushion
curves (ASTM D-l 596) may not be accurate because they may be more than I0 years old.
Material composition may be changed during that period.

Shock transmission properties of cushioning materials are measured on a cushion tester.
Figure 4 shows the set up that was used in this research. I.5 inch thick EPS cushion were
cut to dimensions 8” x 5”, and tested using two different drop heights of I8 and 30 inches.

“I” impact” G and “2~5 impact” G’s

Each sample was subjected to 5 impacts and the
were recorded. Weights of 40|bs, 32|bs and 20|bs were used to set the “static stress”
I.Opsi, 0.8 psi and 0.5 psi for each height. So, the total number of drops was 2 x 5 x 3 x
5= I50. The test apparatus used was a LANSMONT MODEL 23 Drop tester. A
piezoelectric accelerometer was mounted on the dropping head of the tester and the
signal was carried by a shielded cable to a “Piezotron” charge amplifier and then on to a
twelve bit analog to digital card on an computer. The peak acceleration of the platen was
recorded together with the corresponding static load. Test Partner (LANSMONT

CORPORATION) was used to analyze the shock pulses. An example of the acceleration,

shock pulse, velocity and displacement recorded in an impact is shown in Figure 4.

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Figure 4. A shock pulse record from corrugated cushion

ASTM D1596 was used as a guideline for all testing. The drop tests onto the EPS cushion

samples were performed as follows:

I. Set up the equipment to conduct drop tests and load the computer program to monitor
and analyze the shock pulses.

2. Put a certain weight on the dropping platen to reach the decided static loading.

3. Insert an EPS cushion sample with the cushion tester (see Figure 5)

4. Raise the platen and drop it onto the cushion.

5. Display the shock pulse on the monitor and read the peak deceleration value.

6. Repeat steps I through 5 for different thicknesses, static stresses and drop heights.

l7

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

l. Lifting mechanism
1 2. Test weights
3. Test platen
I 4. Accelerometer
: 5. Guidcrods
: 6. Test cushion
l 7. Seismicmass
l 5 5
I 8. Charge amplifier
: 9. TwParmerProgram
l
: 2
I * J
6 8 I I
m
7

Figure 5. Dynamic Cushion Tester for Drop test

18

The actual drop heights used on the machine were not 18” and 30” because there is
friction between the guide rode and platen. Consequently, actual platen drop height is
slightly greater than the free fall drop height to compensate for the friction. So equivalent
drop heights based on the impact velocity were used in place of actual drop heights.

The cushion tester used a photoelectric sensor which is mounted just above the impact
surface of the cushion. It measured the amount of time, which is called gate time, for a
'/2” wide trigger blade mounted on the dropping head to rass through it. This time value

can then be substituted into the following equation

1
t

V: (3.1)

where,
V: impact velocity (in/sec)
d= width of the trigger blade= '/2”

t= gate time (sec)

The equivalent free fall drop height h corresponding to this impact velocity must be

obtained from:

= _ (3.2)

where,

h= free fall height
I 9

V= impact velocity (in/sec)
Table 2 shows the gate times and impact velocities required to produce 18” and 30” free

fall heights.

Table 2. Gate times vs free fall drop height

 

 

 

Gate Time (ms) Impact Velocity (in/sec) Free Fall Drop Height (in)
4.27 i 0.02 l l7.9 i 0.57 18 i 0. l 7
3.30 i 0.02 l52.3 i 0.9] 30 i 0.36

 

 

 

 

 

20

3.2.Corruwd board cushions

Several tests were performed to compare corrugate fiberboard cushion properties with
EPS. All corrugated cushion samples were pre-conditioned for at least 24 hours at
standard conditions of 72 F, 50% RH. The board flute type used C-flute, the middle in
profile shape of the three commonly used profiles, A, B ..nd C flutes. All cushion modes
were designed so that cushions were longer in the machine direction except for“shock

absorbance of corrugated board in three different arrangements” (section No. 3.2.3)

3.2.1 Flat and edge crush tests

TAPPI Standard T808 om-86 and ASTM D2808-90 were used to determine the ECT and
FCT. Twenty pre-conditioned specimens were cut by a TMI standard circular sample
cutter and TM 1 standard edge crush sample cutter. A 400 Series TMI Crush Tester,
Model no. l7-36 was used to determine FCT and ECT data. Tests were conducted in
accordance with the applicable standards, except for dipping the edges of the board
sample in molten paraffin for the ECT test. This was done to be closer to actual resistant

forces in nature during drop tests.

3.2.2 The effect of number of layers in the FCT mode
According to the formula [1.10], the number of layers in a flat crush cushion in theory
should have no effect on the G as long as the impact does not completely flatten the flutes.

The force required to crush one layer is the same as the force required to crush whatever

2|

number of layers because the force is transmitted unchanged through the stack of layers.
However, “edge crush” cushions are completely different. The number of layers are
strongly related to G value because they affect the edge length. To demonstrate the effect
of cushion layers in the FCT mode, different numbers of layers of corrugated board was
subjected to constant static loading impacts. To avoid the flutes flattening, weights of 32
lbs, 20 lbs, and I3 lbs were used. Five different corrugated fiberboard cushions in layers
of three, four, five, six, and seven were constructed and tested using an 18 inch fixed drop
height. Regardless of the thickness of cushion used, each layer had the same contact area.
The cushion sizes tested were 8” X 5”. Each cushion was assigned one flat drop and
replicated, so that the static loadings were kept constant at 0.325psi, 0.5 psi, and 0.8 psi.
The test apparatus used was a LANSMONT MODEL 23 cushion tester. Therefore, the
total drops were 3 x 5 x 5= 75 times in this test. The shocks recorded by the software
were filtered at |25 Hz. The reason l25 Hz was chosen as a filter frequency is that
normal shock duration was 20 ms. Then the shock pulse frequency was l/(2 x 0.020): 25

Hz and the recommended filter frequency is 5 times the shock pulse frequency.

3.2.3. Shock transmission of FCT cushions in thlee different arrangements

In the FCT cushion mode, flute strength, which is its mam resistance against compressive
forces applied perpendicular to its surface, is used to attenuate shock values. To
investigate whether there are any differences in the shock levels transmitted by
corrugated cushions due to differences in the alignment of the flutes in the corrugated

board cushion, tests were performed on three sets of square I inch thick 8 in x 8 in C-

22

flute corrugated fiberboard cushions: “mis-aligned flutes”, “perpendicular flutes", and
“aligned flutes”.

To construct linch thickness of corrugated fiberboard cushion, six layers of C-flue
corrugated board were glued together using spray adhesive.

The “mis-aligned flutes” pattern is shown in Figure 6. The layers were glued together,
and their peaks and valleys were lined up.

The “perpendicular flutes” cushions were constructed with layers placed in an alternating
fashion, so the flutes were perpendicular to each other as shown in Figure 7. The “aligned
flutes” cushions were constructed as in Figure 8, with the peaks of a layer aligned with
valleys of another layer.

The effect of flute alignment was evaluated using a drop height of 18 inches on a
LANSMONT MODEL 23 cushion tester with a piezoelectric accelerometer. The platen
weights were 5] lbs, 32 lbs, and 13 lbs so that the static loadings were kept constant at
0.2 psi, 0.5 psi, and 0.8 psi. Each cushion was subjected to five consecutive drops with l
min waiting time. The shock values were recorded afler filtering at 125 Hz. These values
were then averaged over the five cushions tested for each cushion mode. The design

giving the lowest G was selected and used in comparison tests with EPS cushions.

23

 

Figure 6. Mis-aligned flute cushion

24

 

Figure 7. Perpendicular flute cushion

25

 

Figure 8. Aligned flute cushion

26

3.2.4 Shock transmission for ECT cushion

The "edge crush" mode is very strong and is suitable for cushioning heavy weight
products. To investigate its cushion properties and compare to other cushions. EC T
cushions were constructed. For the test, three different size C-flute corrugated boards
were cut to construct edge crush mode cushions: 8” x 5" x l.5", 4” x 5" x 1.5 and 4" x 3"
x l.5. Three platen weights, l3 lbs, 40 lbs and 80 lbs, were used to products 5 different
static stress levels (0.325, I, 2, 4, and 5.3 psi). A fixed drop height of 18 inch was used.

All drops were duplicated 5 times. ASTM D l596-88a guided this test.

3.2.5 Evaluation of prediction formulas
In Chapter 2, there are several formulas to predict the cushioning properties of corrugated

cushions. As outlined earlier, the following formulas predict what happens in a drop:

G =E—C—Tx—L for edge crush mode

G :M for flat crush mode (3.3)
. . h

Dynamic deflection =5 (3.4)

Number of useful drops = Cushion thickness (3.5)
dynamic deflection

 

The above formulas were used to predict read G, dynamic deflection. and number of

drops. The predictions were then compared to actual data.

27

3.3. Comparison between EPS yd corragated board cushions

A comparison between EPS and corrugated cushions was performed.

To construct the best corrugated fiberboard cushion, all test results from section 3.2 were

considered to design the corrugated cushion which would be compared with EPS. Once a

cushioning configuration had been developed, however, the package designer cannot

fully predict how a cushioning system will behave and perform in an actual package

product application. Therefore, the design must be evaluated for performance in a

specific application. For the performance evaluation, the lntemational Safe Transit

Association (lSTA) Pre-Shipment test procedure was used to evaluate this design and to

compare to EPS. For the test, The EDR-3C from lST was used as the product in order to

measure the G’s transmitted in a drop.

The sensor recorded all acceleration-time histories and shock duration for each drop
series. The program, DynaMax, was used to download all data from the EDR-3C. Every
drop was filtered at 125 Hz (no lower than 5 times the basic pulse frequency) to
eliminate “noise”. The overall procedure for this test is as follows:

I. As in Figure 9, identify and label the following surfaces of the package-EDR3C
system: top as ‘ l ’; right side as ‘2’; bottom as ‘3’; left side as ‘4’; front as ‘5’; and back

as ‘6’. Figure 9 shows the labeling of surfaces of the system.

28

1(top)

 

4(left)

 

 

 

 

3(bottom)

Figure 9. Identification of number for surface of the package-EDR3C system

29

2. Identify edges by the number of those two surfaces forming that edge. For example,
the edge forming the top and right side is identified as 1-2.

3. The drop height shall be set based on package—EDR3C system weight; I through
20.99le, 30 inch; 21 through 48 lbs, 24 inches; 41 through 60.99 lbs, 18 inches; and 6|
lb up to and including 100.001bs, 12 inches. (specification do exist for heavier product).
The weight of package-EDR3C was less than 30 lbs. so the drop height was set to 30
inches.

4. Drop or impact the package-product system as specified under following sequence

(1) Flat on one of the smallest face

(2) Flat on the other of the smallest face
(3) Flat on one of the medium face

(4) Flat on the other of the medium face
(5) Flat on one of the largest face

(6) Flat on the other of the largest face
(7) Comer drop (3 comer).

5. Inspect both the package and the product. The EDR was regarded as the product. All

shock responses were recorded and downloaded into the computer through a USB cable.

The Dynamax software was used to analyze shock pulses. The shock pulses were

displayed by the computer program. (See figure 10).
lSTA standards include the influence of vibration tests on the effectiveness of a package

design. However, the effect of vibration is considered minimal because the EDR is light

weight product. Vibration tests were therefore omitted from the evaluation of cushioning

comparison test between EPS and corrugate fiberboard cushion.

30

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31

CHAPTER 4. RESULTS AND DISCUSSION

4.1. Verifigttion of cushion curves

The validation tests which were used to check the accuracy of the published EPS cushion
curves. By using the dynamic cushion tester, several test combinations were performed to
be compared to the cushion curves; 2 drop heights x 3 static stress levels (psi) x 2
thicknesses. And then all results were reported as peak acceleration levels (G). Table I
shows the averaged peak acceleration levels (G) obtained from EPS cushions. 1n the first
drop, the results revealed that almost all predicted shock transmission values using the
cushion curves were much higher than actual test values except for 1.0 psi at 18” height.
At 1.0 psi, the prediction from the cushion curves corresponded to the actual test result.
However other results were significantly different.

In the 2~5‘h multiple drop, the overall prediction was better than for a single drop
prediction. The predicted values at 0.5 and 0.8 psi corresponded to within 10%. However
other predictions were all significantly different. The cushion curves were published by
ACRO (a brand name of EPS) , which are for their EPS. The EPS used to do the tests
may have been from a different manufacture. So, basically, it is hard to conclude that the
predictions from the cushion curves were not accurate by both comparison to test data.
However, this study revealed that using published cushion curves is not practical, since
its variability depends on the manufacturer of the cushion. Moreover, ASTM D 1596

says “the reproducibility standard deviation is ranged from 9 to 18% of the mean

32

depending on the type and loading of the cushion, and on the type of equipment used by

laboratories”.

33

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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Table 4 shows average shock transmission values for the different number of layers in
FCT cushion. The result shows that the number of layers does influence the G values. but
not very much. G’s were around 40 in all tests, except for the 3-layer cushion. The 3-
layer cushions showed a little higher value than other test results, probably became they
began to be bottom out after the second drop. The results show that G’s tended to

decrease as the number of layers increased. Figure 11 shows the same comparison.

35

 

Static

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

stress Sample No. 3 layers 4 layers 5 layers 6 layers 7 layers
(Psi)
1 45.02 38.51 40.24 33.62 37.57
2 49.01 43.84 39.45 37.37 37.54
3 50.84 43.14 45.62 35.99 42.38
0.325 4 48.36 44.66 40.13 42.28 40.19
5 51.32 38.67 38.57 32.35 38.76
6 47.24 45.88 42.35 40.17 32.43
Average 48.63 42.45 41.06 36.96 38.1 5
Stdev 2.34 3.13 2.56 3.80 3.34
1 80.51 47.91 40.85 38.57 50.44
2 79.14 52.61 45.16 39.57 49.66
3 77.54 51.28 49.00 45.26 47.92
0 5 4 79.24 49.27 52.36 52.07 45.43
' 5 79.51 55.26 49.26 41.26 49.27
6 78.36 47.73 50.16 49.28 47.28
Average 79.05 50.68 47.80 44.34 48.33
Stdev 1.01 2.95 4.13 5.49 1.83
1 137.96 137.10 55.55 37.21 32.22
2 145.32 128.21 52.33 32.22 35.07
3 136.42 127.70 58.32 35.39 39.25
0 8 4 132.36 125.63 52.36 33.28 31.92
° 5 138.25 130.25 55.93 39.25 30.25
6 129.35 118.25 51.26 31.25 31.28
Average 136.61 127.86 54.29 34.77 33.33
Stdev 5.50 6.14 2.73 3.08 3.32

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Table 4. Shock transmission value vs. number of layers.

36

 

 

Peak G value

90 .00
80.00
70.00
60.00
50.00
40.00
30.00
20.00
10.00

0.00

 

3 layers 4 hyers 5 layers 6 byers 7 hyers
The num berof layer

 

 

Peak 0 value

160.00
140.00
120.00
100.00
80.00
60.00
40.00
20.00
0.00

    

3 layers 4 hyers 5 ayers 6 layers 7 hyers
The num berof hyer

 

 

 

Peak G value

60.1!)
511!)
41.11)
30.00
20.00
10.11)

 

0.11)

3 layers 4 layers 5 layers 6 layers 7 layers
‘Ihe nurrber of layer

 

Figure 11. Shock transmission values vs. number of layers

37

 

 

 

4. 3. Shock transmission vs. layer arrangement

To investigate differences due to the alignment of the flutes in flat crush cushions, three
arrangements of the layers were constructed and tested; “mis-aligned flutes”,
“perpendicular flutes”, and “aligned flutes”.

Tables 5 and 6 show the average peak acceleration and dynamic deflection of flat crush
cushions in three different arrangements. Figure 12 to 13 show the same results. At 0.2
psi static loading, the results showed no significant difference among the three patterns.
The peak accelerations in the first drop were within i 4g’s. After the fourth drops, the G
values rise dramatically because cushions bottom out.

At 0.5 psi static loading, the results also showed no major difference. The peak
accelerations in the first drop were within i 6 g’s. The dynamic deflection test at 0.5 psi
also did not show any major difference. However result from the second and third drops
showed more dynamic deflection in “mis-aligned flutes” than “aligned flute”.

At 0.8 psi static loading, the arrangements revealed different characteristics. “Aligned
flutes” had the highest peak G (48.65G), while “mis-aligned flutes” had the lowest peak
of 30.22 G. “Perpendicular flutes” showed a middle level of peak (36.51G). The reason
for this result could be inferred from their structure. The “Aligned flutes” are most rigid
cushion type among three patterns because the medium’ peak and valley are lined up well
and keep a strong support each other. So this type of cushion was relatively more
resistant in multiple drops but had high peak G’s. “mis-aligned flutes” were arranged in a
completely opposite way, the peaks and valleys of the corrugate board missed their lines
and got more dynamic deflection than other two arrangement patterns. After all, it had the

most shock attenuating characteristics. “perpendicular flutes” showed intermediate levels

38

between “mis-aligned flutes” and “Aligned flute”. Its dynamic shock was higher than
“mis-aligned flute, and lower than the others.

In multiple drops, “aligned flutes” showed better performance although they had the
highest shock transmission in the first drop. The dynamic deflection at 0.8 psi was lower
than “mis-aligned” flutes. In the 2'” drop at 0.8 psi, the thickness of “aligned flue” mode
was 0.98” while the “mis-aligned” was 0.90”. Therefore, the result was proved “aligned
flutes” are more durable for multiple drops.

At 0.8 psi, cushions exceeded their maximum limit after the third consecutive drop. All
of the peak transmittance was more than 170 G. So, further drop tests were omitted. For
future research, more layers of corrugated board and higher static loadings should be

considered to give clearer results.

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180.00

160.00

140.00

120.00

100.00

80.00

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60.00

   
 

40-00 _ : , --Al|igned1|u1aa

 

 

 

 

  
  
   

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0 1 2 3 4 5 6
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0 1 2 3 4 5 6
Drop tines

 

 

 

 

Figure 12. Shock GS and dynamic deflections of corrugated cushions in three

arrangements. (Drop height=l8”, Static stress=0.2 psi)
42

 

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E
, 0.90
-o-Amgnod
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0.70
0 1 2 3 4 s 6
Droptimos

 

 

 

Figure 13. Shock G’s and dynamic deflections of corrugated cushions in three

arrangements. (Drop height=l8”, Static stress=0.5 psi)

43

 

250.00

200.00

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0 1 2 3 4 5 6
nap time

 

 

 

 

Figure 14. Shock 6’5 and dynamic deflections of corrugated cushions in three

arrangements. (Drop height=l8”, Static stress=0.8 psi)

44

4.4 Shock transmisson of edge cru_sh mode(ECT) cum

Table 7 compares the performance of C-flute corrugated board at different static loads by
examining the peak G level. Investigation of this result reveals specific characteristics of
ECT mode cushion. Test results showed that drops from the least static loading produced
the highest average peak acceleration, 221.93 g. Drops form the highest static loading
(test #5) produced the least peak acceleration. Figure 14 shows that the peak accelerations
are in inverse proportion to static loading. The former dynamic drop test showed flat
crush mode cushions would easily bottom out in high energy absorption impacts because
they have exceeded their energy absorbing capacity. Edge crush mode cushions, however.
could attenuate effectively at least more than 4.0 psi of static loading. From the static
loading 0.325 to that of 2.0 psi, every drop produced over 150 g. Therefore edge crush
mode cushion is considered that this type of cushion is not proper for light products. but

heavy products.

45

 

 

 

 

 

 

 

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50

 

 

Static Stress (psi)

 

Figure 14. Shock transmission of edge crush mode cushions.

47

 

4.5 Evaluation of prediction formulas
The mathematical formulas to predict G and number of useful drops were tested. The

formulas introduced in Chapter 2 are:

ECTxL FCTxA

 

G 3.3
W W ( )
. . h

Dynarmc deflection :6 (3.4)

Number of useful drops = Cushion thtclmess (3.5)

dynamic deflection

In this study, the above formulas were used to predict overall cushion properties and the
predictions were then compared to actual data.

Flat and edge crush tests were performed according to the standards cited earlier, and
average values were calculated for both. The data from flat crush test and edge crush test
are summarized in Appendix B.

The data in Table 8 shows that the equations did not predict peak G very well.

48

 

 

 

 

 

 

 

 

 

 

 

 

 

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49

4.6 Corrugated vs. EPS cushions

Through several laboratory test results above, the proper design was selected for
comparison tests between corrugated cushions and EPS.

First of all, since ECT mode cushions are not suited for light items, FCT mode cushions
were not used for this study because EDR3C weighs less than 3 lbs. In former tests. it
was proved that shook transmissions of corrugate cushions in F CT mode were similar to
each other, regardless of the number of layers, until they became bottomed out. Also, the
arrangement of layers did not affect the result much. Even though result showed “mis-
aligned” flutes were slightly better than other two cushion modes, the difference was
small at low static loadings. Therefore, the design used for this comparison test was 9
layers to match the same thickness to EPS cushion. Table 9 summarizes the maximum
G’s experienced by the EDR3C during the drop test sequence; the measured G for each
of the six flat surfaces of the package-product system is presented. The maximum G
experienced by the product was 125.5 g’s on the bottom surface for the EPS cushion and
135.8 g’s for the corrugated cushion. There results showed that the ability of corrugated
cushions to attenuate shocks is comparable with EPS at this static stress.

The effect of consecutive drops on cushioning performance was also investigated. For
light weight products, more than five drops should be conducted to find out when
performance of the materials starts to deteriorate. The cushioning performance kept

constant peak G values.

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51

CHAPTER 5. CONCLUSIONS
Through this study, several corrugated cushion properties and performance comparisons
between EPS and corrugated board were investigated.

The conclusions reached in this research are:

1. Cushion curves may not always be practical method to predict G‘s. A new approach
should be developed for other commercialized EPS cushions.

2. As long as a drop onto an F CT cushion does not came the cushion to bottom out
(compact the paper into a solidness), the dynamic shock exceeds cushion’s attenuation,
G’s is not influenced by the number of layers of corrugated board in F CT mode.

3. 0’5 can be improved or grow worse by aligning the layers in an FCT cushion.

- The mis-aligned cushion mode has the best shock attenuation value in the first drop
performance and worst in multiple drops.

- The aligned cushion mode has the worst shock attenuation value in the first drop
performance and worst in single drop.

4. Peak G prediction formulas for corrugated cushions are not accurate.

5. The performance test using EDR revealed that corrugated cushions provide excellent
protection for items that are subjected to a limited number of drops.

6. it is not clear whether corrugated board is more economical than EPS, because:

- EPS can be molded but corrugated board can not; making the construction of corrugated
cushion more labor required.

- Performance issues with corrugated board like moisture sensitivity, fatigue. dusting and

consumer acceptance are difficult to evaluate

52

Appendix A

Table A1. Peak accelerations for EPS at 18 inch drop height

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Static 2-5th
Stress Sample lst 2nd 3rd 4th 5th (ave)
(PS!)

1 30.23 38.31 39.64 40.15 39.84 39.49
2 32.95 39.74 40.14 40.32 43.56 40.94
3 27.49 39.31 36.24 40.36 42.78 39.67

0.5 4 29.73 40.25 36.46 40.27 37.46 38.61
5 31.69 39.42 39.46 41.58 45.34 41.45
Average 30.42 39.41 38.39 40.54 41 .80 40.03

Stdev 2.07 0.71 1.88 0.59 3.13 1.15
1 28.35 28.89 30.96 32.07 33.81 31.43
2 29.18 25.68 29.84 31.69 35.69 30.73
3 22.98 27.84 30.31 32.49 37.46 32.03
0.8 4 25.80 29.32 31.25 33.28 37.59 32.86
5 19.07 23.37 25.39 27.79 30.45 26.75
Average 25.08 27.02 29.55 31.46 35.00 30.76

Stdev 4.14 2.48 2.39 2.14 2.97 2.37
1 33.25 37.32 42.56 44.31 44.67 42.22

2 38.46 39.47 42.19 41.32 45.46 42.1 1
3 35.47 40.12 43.28 45.36 47.24 44.00
1.0 4 32.17 40.25 44.32 45.25 46.59 44.10
5 35.69 37.31 39.46 44.89 45.55 41.80
Average 35.01 38.89 42.36 44.23 45.90 42.85

Stdev 2.44 1.47 1.81 1.68 1.01 1.1 1

 

53

 

Appendix A (continued)

Table A2. Peak accelerations for EPS at 30 inch drop height

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Static 2-5th
Stress Sample lst 2nd 3rd 4th 5th (ave)
(PS!)

1 47.26 68.45 71.46 78.69 78.45 74.26

2 47.65 66.49 71 .84 75.46 79.94 73.43

3 44.25 66.83 72.59 76.20 77.19 73.20

0.5 4 48.87 68.86 73.61 76.2 79.05 74.43
5 45.57 70.46 74.62 77.46 77.42 74.99

Average 46.72 68.22 72.82 76.80 78.41 74.06

Stdev 1.82 1.61 1.30 1.28 1.14 0.74

1 49.92 66.45 69.15 73.92 73 .68 70.80

2 48.46 65.07 69.46 72.33 75.64 70.63

3 51.78 66.54 70.49 72.79 78.95 72.19

0.8 4 50.12 64.59 71.98 72.46 75.46 71.12
5 48.34 66.59 70.46 72.79 77.79 71.91

Average 49.72 65.85 70.31 72.86 76.30 71.33

Stdev 1.41 0.95 1.1 1 0.63 2.08 0.69

Sample lst 2nd 3rd 4th 5th €333;
1 38.56 46.45 53.46 58.69 60.45 54.76
2 35.40 47.83 51.84 55.46 62.35 54.37

1-0 3 37.24 46.83 52.79 55.20 63.28 54.53
4 40.11 48.46 53.71 59.8 62.19 56.04

5 37.48 48.28 52.58 60.1 1 65.31 56.57

Average 37.76 47.57 52.88 57.85 62.72 55.25

Stdev 1.74 0.89 0.74 2.36 1.77 0.99

 

54

 

Table B1. Result of edge crush test and flat crush test

Appendix B

 

 

 

 

 

 

 

 

 

 

 

Sample ECT (lb/inz) FCT(1b/in)
1 40.80 22.30
2 32.50 23.00
3 34.20 25.30
4 36.70 27.90
5 38.70 24.90
Average 36.58 24.78
Stdev 3.34 2.07

 

55

 

Appendix C
Table C 1. G values for different number of layers of corrugated board cushion. (Drop
height= 18”)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Static stress Sample No. 3 layers 4 layers 5 layers 6 layers 7 layers
1 45.02 38.51 40.24 33.62 37.57
2 49.01 43.84 39.45 37.37 37.54
3 50.84 43.14 45.62 35.99 42.38
0 325 4 48.36 44.66 40.13 42.28 40.19
' 5 51.32 38.67 38.57 32.35 38.76
6 47.24 45.88 42.35 40.17 32.43
Average 48.63 42.45 41.06 36.96 38.15
Stdev 2.34 3.13 2.56 3.80 3.34
1 80.51 47.91 40.85 38.57 50.44
2 79.14 52.61 45.16 39.57 49.66
3 77.54 51.28 49.00 45.26 47.92
0 5 4 79.24 49.27 52.36 52.07 45.43
° 5 79.51 55.26 49.26 41.26 49.27
6 78.36 47.73 50.16 49.28 47.28
Average 79.05 50.68 47.80 44.34 48.33
Stdev 1.01 2.95 4.13 5.49 1.83
1 137.96 137.10 55.55 37.21 32.22
2 145.32 128.21 52.33 32.22 35.07
3 136.42 127.70 58.32 35.39 39.25
0 8 4 132.36 125.63 52.36 33.28 31.92
' 5 138.25 130.25 55.93 39.25 30.25
6 129.35 118.25 51.26 31.25 31.28
Average 136.61 127.86 54.29 34.77 33.33
Stdev 5.50 6.14 2.73 3.08 3.32

 

 

 

 

 

 

 

 

 

 

 

 

 

 

56

 

Appendix D

Table D1. G values for three different arrangements of layers.

(Drop height= 18”, Static stress=0.2)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Arrangement Sample No. lst drop 2nd drop 3rd drop 4th drop 5th drop
1 45.56 52.29 60.48 142.72 1 79.46
2 41.04 47.77 51.67 133.94 169.35
Aligned 3 40.90 47.42 60.10 144.68 170.36
flutes 4 41.95 47.94 60.37 143.47 180.25
5 45.89 53.57 62.46 146.25 169.42
Average 43.07 49.80 59.02 142.21 173.77
Stdev 2.46 2.90 4.21 4.81 5.58
1 40.59 41.42 67.39 136.25 182.35
2 40.13 41.83 65.36 148.36 179.53
Perpendicular 3 42.36 45.36 63.47 142.36 186.63
flutes 4 41.26 46.24 64.25 158.35 194.26
5 40.28 48.00 60.42 147.53 177.36
Average 40.92 44.57 64.18 146.57 184.03
Stdev 0.91 2.86 2.57 8.17 6.69
1 38.28 43.65 63.23 139.46 186.82
2 40.46 45.29 66.47 146.36 190.25
Miss- aligned 3 37.47 47.25 69.36 138.25 184.25
flute 4 40.47 50.25 67.35 150.35 200.35
5 40.59 51.58 65.36 142.36 189.25
Average 39.45 47.60 66.35 143.36 190.18
Stdev 1.47 3.31 2.28 5.00 6.14

 

 

 

 

 

 

 

 

 

 

 

 

 

 

57

 

Appendix D (continued)

Table D2. G values for three different arrangements of layers.

(Drop height= 18”, Static stress=0.5 psi)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Arrangement Sample No. l 2 3 4 5
1 37.24 52.13 164.81 202.21 227.34
2 40.04 47.04 154.40 204.31 240.24
A]. d 3 38.62 55.13 167.35 204.25 238.53
111$: 4 38.70 53.23 165.33 203.24 245.33
5 34.29 49.04 162.56 206.93 242.42
Average 37.78 51.31 162.89 204.19 238.77
Stdev 2.19 3.25 5.04 1.76 6.88
1 43.38 72.07 173.60 202.64 230.85
2 44.93 60.96 199.80 210.07 235.38
Perpendicular 3 41.53 70.69 182.95 209.90 229.58
flutes 4 42.62 66.22 188.30 208.54 232.56
5 41.38 58.29 179.24 205.33 225.94
Average 42.77 65.65 184.78 207.30 230.86
Stdev 1.46 5.98 9.96 3.22 3.51
1 49.49 53.29 168.46 197.21 224.21
2 39.21 63.48 171.46 196.32 203.46
Miss_aligned 3 42.14 60.60 174.73 199.83 231.42
flute 4 46.99 70.00 171.24 193.12 223.28
5 40.61 51.74 169.33 194.49 214.45
Average 43.69 59.82 171.04 196.19 219.36
Stdev 4.37 7.51 2.42 2.58 10.74

 

58

 

Appendix D (continued)

Table D3. G values for three different arrangements of layers.
(Drop height= 18”, Static stress=0.8 psi)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Arrangement Sample No. 1st drop 2nd drop 3rd drop 4th drop 5th drop
1 47.46 101.98 210.36 x x
2 48.38 103.73 207.36 x x
Aligned 3 50.25 98.28 205.36 x x
flutes 4 47.80 103.47 225.36 x x
5 49.36 101.25 213.30 x x
Average 48.65 101.74 212.1 1 x x
Stdev 1.15 2.19 9.07 x x
1 35.89 107.47 224.47 x x
2 35.51 108.46 249.36 x x
Perpendicular 3 34.07 106.36 215.36 x x
flutes 4 40.58 110.36 204.36 x x
5 36.49 108.24 212.35 x x
Average 36.51 108.18 221.18 x x
Stdev 2.44 1.47 17.32 x x
1 29.33 121.80 220.35 x x
2 29.62 1 17.24 236.38 x x
. . 3 30.21 125.25 259.3j x x
M‘ssfifllt‘egned 4 29.60 129.25 221.36 x x
5 32.32 122.35 225.46 x x
Average 30.22 123.18 225.89 x x
Stdev 1.22 4.44 7.34 x x

 

59

 

Table D5. Dynamic deflection for three different layer arrangements.
(drop height= 18”, static stress= 0.5 psi

Appendix D (continued)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Arrangement Sample No. lst drop 2nd drop 3rd drop 4th drop 5th drop 1st drop
1 1.26 1.17 1.065 0.95 0.94 1.32
2 1.27 1.17 1.065 0.95 0.94 1.32
Aligned 3 1.26 1.15 1.067 0.96 0.92 1.32
flutes 4 1.28 1.16 1.066 0.96 0.92 1.32
5 1.26 1.16 1.063 0.95 0.93 1.32
Average 1.27 1.16 1.07 0.95 0.93 1.32
Stdev 0.01 0.01 0.00 0.01 0.01 0.00
1 1.275 1.125 1.05 0.94 0.92 1.32
2 1.265 1.12 1.05 0.95 0.93 1.32
Perpendicular 3 1.26 1.13 1.06 0.93 0.92 1.32
flutes 4 1.27 1.12 1.07 0.95 0.92 1.32
5 1.26 1.13 1.05 0.94 0.92 1.32
Average 1.27 1.13 1.06 0.94 0.92 1.32
Stdev 0.01 0.00 0.01 0.01 0.00 0.00
1 1.25 1.125 1.04 0.95 0.91 1.32
2 1.23 1.125 1.05 0.92 0.9 1.32
M' 1' d 3 1.24 1.122 1.05 0.92 0.91 1.32
“:33“ 4 1.23 1.12 1.03 0.92 0.91 1.32
5 1.21 1.12 1.03 0.92 0.91 1.32
Average 1.23 1.12 1.04 0.93 0.91 1.32
Stdev 0.01 0.00 0.01 0.01 0.00 0.00

 

60

 

Appendix D (continued)

Table D5. Dynamic deflection for three different layer arrangements.
(drop height= 18”, static stress= 0.5 psi)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Arrangement Sample No. 1st drop 2nd drop 3rd drop 4th drop 5th drop 1st drop
1 1.26 1.17 1.065 0.95 0.94 1.32
2 1.27 1.17 1.065 0.95 0.94 1.32
Aligned 3 1.26 1.15 1.067 0.96 0.92 1.32
flutes 4 1.28 l . 16 1.066 0.96 0.92 1.32
5 1.26 1.16 1.063 0.95 0.93 1.32
Average 1.27 1.16 1.07 0.95 0.93 1.32
Stdev 0.01 0.01 0.00 0.01 0.01 0.00
1 1.275 1.125 1.05 0.94 0.92 1.32
2 1.265 1 . 12 1.05 0.95 0.93 1.32
Perpendicular 3 1.26 1.13 1.06 0.93 0.92 1.32
flutes 4 1.27 1 . 12 1.07 0.95 0.92 1.32
5 1.26 1.13 1.05 0.94 0.92 1.32
Average 1.27 1 . 13 1.06 0.94 0.92 1.32
Stdev 0.01 0.00 0.01 0.01 0.00 0.00
1 1.25 1.125 1.04 0.95 0.91 1.32
2 1.23 l . 125 1.05 0.92 0.9 1.32
Miss-aligne d 3 1.24 1 . 122 1.05 0.92 0.91 1.32
flute 4 1.23 1.12 1.03 0.92 0.91 1.32
5 1.21 1.12 1.03 0.92 0.91 1.32
Average 1.23 1.12 1.04 0.93 0.91 1.32
Stdev 0.01 0.00 0.01 0.01 0.00 0.00

 

61

 

Appendix B

Table E1. G’s for corrugate cushions in ECT mode

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Static stress (psi) Sample No. Drop height Peak G
1 16 210.19
2 16 220.35
3 16 238.82
0325 4 16 228.13
5 16 212.17
Average 16 22 l .93
1 18 210.34
2 18 226.38
3 18 210.8
0325 4 18 232.82
5 18 222.13
Average 1 8 220.49
1 18 163.40
2 18 160.42
1 0 3 18 159.83
' 4 18 169.63
5 18 168.55
Average 1 8 1 64.3 7
1 18 160.42
2 18 158.83
3 18 159.36
2'0 4 18 161.49
5 18 158.83
Average 1 8 1 59.78
1 32 218.49
2 32 210.32
3 32 199.46
2'0 4 32 202.46
5 32 180.46
Average 32 202.24
1 18 92.45
2 18 80.83
3 18 92.46
4'0 4 18 91.54
5 18 86.46
Average 1 8 88.75
1 18 43.00
2 18 53.00
3 18 62.00
5'0 4 18 8.26
5 18 1.45
Average 1 8 52.67

 

62

 

Appendix B

Table E1. G’s for corrugate cushions in ECT mode

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Static stress (psi) Sample No. Drop height Peak G
1 16 210.19
2 16 220.35
3 16 238.82
0325 4 16 228.13
5 16 212.17
Average 16 22 l .93
1 18 210.34
2 18 226.38
3 18 210.8
0325 4 18 232.82
5 18 222.13
Average 1 8 220.49
1 18 163.40
2 18 160.42
1.0 3 18 159.83
4 18 169.63
5 18 168.55
Average 18 164.37
1 18 160.42
2 18 158.83
3 18 159.36
2'0 4 18 161.49
5 18 158.83
Average 18 159.78
1 32 218.49
2 32 210.32
2 0 3 32 199.46
' 4 32 202.46
5 32 180.46
Average 32 202.24
1 18 92.45
2 18 80.83
3 18 92.46
4'0 4 18 91.54
5 18 86.46
Average 18 88.75
1 18 43.00
2 18 53.00
3 18 62.00
5'0 4 18 8.26
5 18 1.45
Average 18 52.67

 

 

Appendix F

Table F1. Performance test results for EPS cushion, using EDR at 18 inches’ height.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Event No. Peak X Peak Y Peak Z Peak R Comment

1 35.63 7.353 93.223 100.377

2 -4.496 23.613 132.71 135.541

3 1 1.336 1 1.822 140.943 142.382 Bottom
4 19.323 19.503 136.359 139.882

5 17.43 12.291 139.409 141.46

6 34.637 -13.246 -95.27 100.678

7 -24.46 19.335 -1 15.24 1 19.3834

8 -l4.738 20.003 -95.46 98.64046 Top
9 13.164 23.044 -125.34 128.1188

10 -17.052 34.46 -107.89 114.5361

1 1 -85.731 -11.112 17.476 87.203

12 -89.385 -10.969 -13.778 91.056

13 -87.848 -10.647 17.186 89.132 Left
14 -81.867 24.122 -23.353 83.349

15 -78.348 10.399 14.037 79.649

16 84.345 8.016 16.587 85.031

17 82.413 8.948 -16.876 83.994

18 85.038 -1 1.298 -15.445 86.454 Right
19 87.066 15.53 30.318 87.709
20 88.036 8.007 18.194 89.36
21 20.46 -89.46 -31 .051 96.88069
22 17.975 -88.293 -18.565 91.567
23 -19.46 -97.89 31.356 104.6152 Front
24 -24.67 -94.61 33.772 103.4418
25 17.64 -92.31 27.456 97.90882

26 -16.661 99.072 -13.21 101.304

27 -12.828 103.557 -15.225 105.189

28 -16.328 104.482 21.434 106.428 Back
29 -18.859 104.815 -17.195 106.454

30 -1 1.851 105.707 20.142 107.673

31 33.703 -35.174 -26.905 53.798

32 34.407 -39.501 -25.881 56.549

33 39.158 -39.614 37.368 60.371 Comer
34 -34.039 31.633 -30.214 53.597

35 -42.931 38.704 -29.989 62.637

 

 

Appendix F (continued)

Table F2. Performance test results for EPS cushion, usinj EDR at 30 inches’ height.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Event No. Peak X Peak Y Peak Z Peak R Comment

1 12.815 -25.758 141.887 145.214

2 23.299 15.725 142.625 146.912

3 14.485 25.629 139.004 143.251 Bottom
4 -15.147 -21.333 136.314 139.884

5 16.845 22.442 144.801 148.737

6 —20.342 -27.161 -101.956 108.089

7 16.538 37.452 -136.562 143.682

8 -22.572 -32.467 -125.879 133.173 Top
9 32.915 27.738 -135.895 144.828

10 -30.039 -30.771 -1 13.959 122.363

1 1 -73.336 9.310 10.913 74.933

12 -65.952 14.631 13.242 68.692

13 -73.368 -15.564 23.343 76.149 Left
14 -67.834 -13.083 22.271 70.457

15 -77.019 -9.502 20.054 78.948

16 -77.487 -14.412 19.987 79.380

17 70.618 9.406 27.287 72.367

18 69.277 7.684 -22.033 73.184

19 77.976 1 1.526 23.198 78.741 Right
20 66.618 13.789 -15.508 67.514
21 80.114 17.43 ~11.838 81.938
22 12.021 103.132 29.131 107.734
23 12.792 109.755 31.992 1 15.666
24 10.438 1 1 1.576 28.236 1 15.92 Front
25 10.383 100.657 24.524 104.237
26 10.696 105.312 -28.175 108.620
27 21.078 -84.649 27.542 88.691
28 17.272 -90.887 30.866 93.503
29 17.328 -84.021 25.219 87.048 Back
30 17.886 -84.615 25.637 88.496
31 9.124 -85.872 -4.231 86.795
32 26.619 -33.305 -34.683 42.586
33 -31.227 -33.685 -28.550 45.800
34 -34.817 -39.438 31.206 52.240 Comer
35 «23.615 27.542 -31.501 40.440
36 23.466 32.765 -25.082 40.402

 

65

 

References

1. Burgess, G..l., Eric Wenger, “Performance of corrugated board as a cushioning
material Consortium of distribution packaging, Michigan State
University, 1992, PP 39-65

2. Burgess, G..l., “Advanced Packaging Dynamics-course pack, School ofpackaging
Michigan State University, 2002.

3. Dinna R. Bruce, “Demonstration of Packaging Materials Alternatives to Expanded
Polystyrene”, National Risk Management Research Laboratory, 1998, April

4. Kirkpatrick, J. and Sek, M., “Replacement of polymeric cushioning with corrugated
fibreboard-case study” 10th IAPRI World Conference on Packaging, PP 267-276,
Melbourne, March.

5. Maltenfort, G.G., “Corrugated Shipping Containers: An Engineering Approach
Jelmar Publishing Co., Inc. , Plainview, NY 11803, 1988

6. Schueneman, Herber H, “Package Drop Testing: What is the Data Really Telling
US? ”, Packaging Technology & Engineering, April 1995.

7. Sek, M., “Corrugated F iberboard as a Cushioning Medium in Protective Packaging
packaging India, 2000, PP 33-41

8. Sek, M. et al(1999) “Performance Characteristics of a Paper-based Material
Corrupad for cushioning application” 11th IAPRI World Conference on Packaging. PP
403-415, Singapore, July.

9. Thewasano Supawadee, “Performance of Recycled Corrugated F iberboard Under
Various Temperatures And Humidities ”, The School of Packaging, Michigan State
University, 1993.

10. ASTM D 2808-90, “Compressive Strength of Corrugated Fiberboard American
Society for Testing and Material, 1991.

1 1. ASTM D 1596-91, “Dynamic Shock Cushioning Characteristics of packaging
materials”, American Society for Testing and Materials, 1991.

66

12. T808 om-86, “Flat Crush Test of corrugated Board ”, Technical Association of the
Pulp and Paper Industry, 1986.

67

12. T808 om-86, “Flat Crush Test of corrugated Board”, Technical Association of the
Pulp and Paper Industry, 1986.

67

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