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THESE;

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This is to certify that the

thesis entitled

PANELING OF PLASTIC BOTTLES

presented by

Ramalingam V. Sellapareddy

has been accepted towards fulfillment
of the requirements for

Masters degree in Packaging

 

 

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(1 Major professor

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0-7 639 MS U is an Affirmative Action/Equal Opportunity Institution

 

 

LIBRARY

Michigan State

University

 

 

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

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6/01 c:/ClRCJDateDuo.p65-p.15

 

PANELING OF PLASTIC BOTTLES

BY

Ramalingam V. Sellapareddy

A THESIS

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

MASTER OF SCIENCE

School of Packaging

2002

ABSTRACT

PANELING OF PLASTIC BOTTLES

BY

Ramalingam V. Sellapareddy

Paneling of plastic bottles has been observed in
several packaged products. Until now, the fundamentals
involved in causing the paneling of plastic bottles have
not been clearly understood. There are presently no general
methodologies to resolve paneling problems. Pressure
differential has been identified as a possible cause of
paneling. Causes of pressure differential have not been

experimentally verified.

This study demonstrated experimentally that one
possible cause of paneling may be removal of oxygen from
the headspace, leading to a pressure differential. Such
factors as wall thickness variation and creep, probably
influenced the occurrence of paneling. A question guide is
suggested for analyzing paneling in order to find solutions

to paneling problems.

DEDICATION
This thesis is dedicated to my wife, Dr. Geetha Bhai Pillai
and my two sons, Diivanand and Deeban, who gave me all the
encouragement and support I needed to complete my thesis

and degree.

iii

ACKNOWLEDGEMENTS

I thank Dr. Hugh Lockhart for the guidance, patience and
understanding shown to me during the writing of my thesis
and in making my thesis a success. I would also like to
thank Dr. Susan Selke, Dr. Gary Burgess and Dr. K.Jayaraman
for their guidance and support. My hearty thanks to

Mr. Robert Hurwitz for helping in setting up the
experiment,and Mr. Supoj Pratheepthinthong for helping me

to take photographs of my experiment.

iv

TABLE OF CONTENTS

LIST OF TABLES ............................................................................. Vi
LIST OF FIGURES ............................................................................ Vfi
KEY TO SYMBOLS OR ABREVIATIONS ................................................ Vfii
INTRODUCTION ................................................................................. 1
CHAPTER 1. LITERATURE REVIEW ................................................... 6
CHAPTER 2. FIELD STUDY OF PANELING ...................................... 12
CHAPTER 3. MATERIALS AND METHODS .......................................... 20
CHAPTER 4. DATA AND RESULTS ................................................... 37
CHAPTER 5. CONCLUSION AND FUTURE WORK ................................. 51

APPENDICES:

APPENDIX A. Question Guide for analyzing the causes of
paneling in the field ........................................ 54

APPENDIX B. 4 Liter hot filled ketchup HDPE bottle ......... 57

APPENDIX C. 1 Liter and 2 Liter floor cleaner
HDPE bottle ............................................................ 61

APPENDIX D. 32 Ounce cleaning product HDPE bottle ........... 65

APPENDIX E. 24 Ounce hot filled chocolate syrup
HDPE bottle ............................................................ 69

APPENDIX F. 1 Liter hair root lifter HDPE bottle ............... 73

APPENDIX G. HDPE bottle containing 240 Dietary
supplement tablets ............................................... 76

BIBLIOGRAPHY ................................................................................. 80

Table

Table

Table

Table

Table

Table

Table

Table

Table

Table

Table

LIST OF TABLES

l Condensed version of the possible causes of

paneling of plastic bottles .................................. 11
2 Shampoo bottles — Body thickness measurements. 38
3 Dietary supplement bottles - Body thickness

measurements .............................................................. 39
4 Hair care product bottles — Body thickness

measurements .............................................................. 4O
5 Shampoo bottles — Average body thickness

measured circumferencially from heel to

shoulder ..................................................................... 42
6 Dietary supplement bottles — Average body

thickness measured circumferencially from

heel to shoulder ........................................................ 42
7 Hair care product bottles — Average body

thickness measured circumferencially from

heel to shoulder ....................................................... 42
8 Shampoo bottles — Vacuum testing values /

time taken to panel ................................................. 44
9 Dietary supplement bottles — Vacuum testing

values / time taken to panel ................................. 44
10 Hair care product bottles — Vacuum testing

values / time taken to panel ................................. 44
11 Vacuum and time ranges to panel ............................ 45

vi

Figure
Figure
Figure

Figure

Figure
Figure
Figure

Figure

Figure

Figure

Figure

Figure

Figure

Figure

Figure

Figure

10

ll

12

l3

14

15

16

LIST OF FIGURES

Undeformed Bottle ........................................................ 2
Paneled Bottle ............................................................. 3
Experiment — Vacuum Testing .................................... 23

Measurement of the thickness of a point

on the body of the bottle ....................................... 24
Test sample bottles .................................................. 25
Experiment — Dietary supplement bottle ................ 26
Deformation by 1/32 of an inch .............................. 30

Dietary supplement bottle — Depth of paneling
of 1/8 inch ................................................................. 31

Dietary supplement bottle — Depth of paneling
of 1/4 inch ................................................................ 32

Shampoo bottle — Depth of paneling of
1/8 inch ..................................................................... 33

Shampoo bottle — Depth of paneling of
1/4 inch ...................................................................... 34

Hair care product bottle — Depth of paneling

1/8 inch ...................................................................... 35
Hair care product bottle — Depth of paneling

1/4 inch ...................................................................... 36
Mapping of paneling Shampoo bottles .................. 46

Mapping of paneling Dietary supplement
bottles ............................................................................... 47

Mapping of paneling Hair care product
bottles ........................................................................ 48

vii

KEY TO SYMBOLS OR ABBREVIATIONS:

PET
PVC

OD
m1

mmHg:
ian:

K
F
%

fl
Oz

HDPE:

Polyethylene terephthalate
Polyvinyl chloride
High-density polyethylene
Outside diameter
Milliliter

Millimeters of mercury
Inches of mercury

Kelvin

Fahrenheit

Percentage

Inches
Flow
Ounze

viii

INTRODUCTI ON

Paneling is the term used to describe the action of a
plastic bottle when it forms a concavity somewhere in the
body. There may be one concavity or more than one. Figure 1
shows an undeformed bottle and Figure 2 shows a paneled
bottle. These bottles have been used for differentiating
deformed from undeformed bottle, and have not been used in
any experiments in this thesis. The body of the bottle is
the section of the bottle between the shoulder and the
heel. This section can be cylindrical, square, rectangular
or oval in cross section.

The paneling of plastic bottles has been observed in a
variety of packaged products. Examples of these products
are nutritional/dietary supplements, hot-filled products,
agricultural chemical products, sanitizers and hair care
products. The magnitude of paneling has been observed from
a size of 1 inch in length, 1/2 inch in width and a 1/8
inch in depth, to a larger area of 3 inches in length,

1 1/2 inches in width and 3/4 inch in depth. These examples
of paneled bottles have been observed during outgoing
inspection, upon breakdown of shipping units when stocking

shelves and on the shelves of various retail outlets.

 

Figure 1. Undeformed Bottle

 

Figure 2. Paneled Bottle

Study of the paneling of plastic bottles is useful
for the following reasons:

(a) There are many requests from manufacturers to provide
solution to overcome paneling of plastic bottles. Some of
these samples have been sent to the School of Packaging
to analyze the cause of paneling. However, manufacturers
often did not provide proper information about how, when
and where the paneling had occurred, so there was no
useful base for analyzing causes and developing
appropriate action plans.

(b) When paneling is encountered during production, it may
require immediate remedy. Due to lack of time, it is
often not possible to do a detailed investigation of
the paneling problem at that time. Rather, a fire
fighting trouble shooting approach is adopted to solve
the problem.

(c) There is a lack of understanding of the phenomena
that cause paneling. An in-depth understanding of the
causes of paneling will enable an appropriate resolution
of paneling problems.

(d) There is a lack of methodology to analyze and resolve
paneling questions. An appropriate analytical or
practical technique will facilitate a systematic problem

solving process. The technique should cover all processes

involved from the moment the product is filled, until the
package reaches the retail shelves.
The goals of this project were:
(a) To gain knowledge for resolving paneling questions.
(b) To gain knowledge on how to design bottles that will
not panel. The design will include the size, shape,
thickness distribution and all dimensions.
(c) To develop a test:
(i) for evaluating the resistance of bottles to
paneling.
(ii) for incoming quality control, to ensure that the
bottles will not panel after filling until they

are sold.

CHAPTER 1
LITERATURE REVIEW

Jones et al., (1963), described possible causes of
paneling of high density polyethylene bottles as the
following:

(a) The loss of product contained in the bottle leaves a
vacuum, which draws in the bottle walls. This loss
results initially from absorption of the product into
the container walls. The continued absorption causes the
product to diffuse through the walls, and it finally
evaporates to the outside. This leads to an increase in
the headspace volume. Since the bottle is tightly capped
to prevent product leakage and air passage from the
outside to the inside of the bottle, underpressure
develops in the headspace. Factors that influence
paneling are solubility and permeability, which depend
on resin density. Resin with lower density results in
higher solubility and permeability.

(b)If the containers are filled and capped when the
product is above room temperature, a partial vacuum will
develop upon cooling of the contents due to a reduction
in the volume of the product. Likewise, if the container
is capped while the head space is full of foam, a vacuum

will develop on condensation of the foam.

No experimental verification of these causes of paneling
was presented.
According to Jones et al., (1961), paneling is affected by
the shape of the bottle. For example a comparative storage
test for 30 days at 140°F with motor oil in a four ounce
Boston Round bottle and a four ounce Flat Oval bottle,
showed that the four ounce Boston Round bottle had
significant wall collapse, whereas the four ounce Flat Oval
bottle had very slight wall collapse.

Rosato D.V. et al., (1989), described possible causes

of paneling of high density polyethylene bottles as the

following:

a) Permeation — The contents or components of the contents
may permeate sufficiently to create a
partial vacuum in the container.

1» Swelling — The chemical contents of the container may

cause swelling of the surface of the wall
of the bottle.

0) Gas solution - Certain materials will absorb gases,
usually oxygen, from the headspace of the
sealed container and create a partial
vacuum. It was not clearly explained
whether the “certain material” referred to

product or the package.

(D Oxidation - Some materials oxidize easily, thus
removing the oxygen from the headspace
and creating a partial vacuum.
Unpigmented polyethylene will not protect
against ultra—violet light which acts as
an oxidative catalyst on some products
to remove oxygen from the headspace to
creating a partial vacuum.

e) Hot fill — Filling and sealing of contents at
significantly elevated temperature, may
result in contraction on cooling, to form
a partial vacuum.

Again, there was no experimental verification of the causes

of paneling.

Dimitri Tsiourvas et al., (1993), has highlighted

that the pressure difference between the inside and the

outside of the container can be created by:

(a) the difference between the filling and storage

temperatures.

(b) the absorption of air contained in the headspace by the

bottle contents.

(C) the creation of gas owing to chemical or biological

processes during storage. (This should not be a factor in

paneling, since the creation of gas would increase the

internal pressure and lead to bulging of the body of the
bottle, not paneling).

The author’s experimental work was confined to three
layer coextruded bottles (polyamide 6/bonding layer/high
density polyethylene). He subjected four different bottle
designs to vacuum testing and evaluated their resistance to
deformation.

Van Dijk et al., (1998) highlighted that an
underpressure can occur due to one or more of the
following factors:

(a) Altitude differences (eg. filling at high altitude
followed by transportation to lower altitudes).

(b) Temperature differences (filling at higher than
ambient temperature will result in contraction of the
volume in the bottle and reduction of the headspace
pressure).

(c) Chemical (e.g. oxidation) or physical (solubility)
interactions between the contents and the air in the
headspace of the bottle; in due time, these factors
can cause under pressure to initiate paneling.

The author’s experimental work was confined to
advanced design approaches such as Finite Element Analysis
which was used to evaluate two different designs of

lightweight plastic bottles, a round PET bottle (750 ml)

and a square PVC bottle (1000 ml). The two designs were
tested for their performance in top load, vacuum and impact
resistance. No evidence was presented to prove that the
pressure difference is the cause of paneling of plastic
bottles.

Table 1 shows a summary of suggested causes of
paneling. Vacuum or pressure differences can be created by
loss of product, gas solution, removal of oxygen in the
headspace, differences in temperature, or some combination
of these. Vacuum and pressure differences are obviously
interrelated.

Continental PET Technologies Inc., (1989), claims in
its patent that paneling is affected by the design of the
body of the bottle for a blow molded container which is

formed of a polyester resin. The bottle may be hot filled

with a liquid at a temperature in the order of 180°F-185°F,
and the bottle has a maximum volumetric shrinkage of no
greater than 1%. This has been discussed in U.S. patent
number 4.863.046 (1989) by Continental PET Technologies
Inc., and U.S. patent number 4.877.141 (1989) by Yoshino
Kogyosho Co. Ltd. A pressure resistant bottle-shaped
container has a body, which has panels surrounded by outer
sheaths. Each panel has stress absorbing strips comprised

of vertexes, recessed from the outer surface of the panel

10

towards the interior of the container. It has bending lines
formed in V—shape and inverted V-shape from the vertexes,
towards the outer sheaths. Thus the container does not
retain permanent deformation, by the deformation resulting
from pressure changes at the time of filling the high

temperature liquid content.

Table 1. Condensed version of the possible causes of paneling of plastic bottles

 

 

 

.- 3 g
0 a
03 1- ” a,
1- ,. Oi ‘-
—" '6' 2 if
2 '8 _" u
q, . N G
4: g *6 n:
D o t 5g
3 a :.-. o
c g g c
o _ N
'1 a: C: >'

Causes:

Vacuum/pressure X X

difference due to

loss of product

Vacuum/pressure

difference due to X X X

removal of Oz

in headspace

Vacuum/pressure

difference due to X X X X

difference in

temperature

(hot fill/storage)

Pressure difference X

due to difference in

aMmm:

Resin density X

(solubility/penneability)

Vacuum due X

to condensation of foam

 

 

 

CHAPTER 2

Field Study of Paneling

In order to evaluate and confirm the possible causes
of paneling, an appropriate experiment is required. With
literature review alone, it was not possible to set up an
experiment. Therefore, a field study of packages that had
paneled were studied. Six packages were investigated that
were identified as having serious paneling problems.

They were:

(a) 4 Liter hot filled ketchup HDPE bottle

(b) 1 Liter and 2 Liter floor cleaner HDPE bottles

(c) 32 Ounce cleaning product HDPE bottle

(d) 24 Ounce hot filled chocolate syrup HDPE bottle

(e) 1 Liter hair root lifter HDPE bottle

(f) HDPE bottle containing 240 dietary supplement
tablets

A field study was carried out by using the WQuestion
Guide for Analyzing the Causes of Paneling” shown in
Appendix A for each of these packages.

(a) 4 Liter Hot Filled Ketchup HDPE Bottle:

The paneling was observed at food service outlets a
week after filling. The middle part of the body paneled.
The extent of paneling was about 1.18 inches in length,

1.18 inches in width and 0.39 inch in depth. The

12

 

thickness of the body wall where the bottle had paneled
was about 0.0394 inch.

Underpressure inside the bottle might have been
caused by an increase in the volume of headspace, due to
shrinkage of volume in the product upon cooling, since
the product was filled at 185° F and cooled to a storage

temperature between 77° F and 113° F.

Underpressure might also have resulted from
condensation of water vapor in the headspace, as the
temperature and hence the saturation vapor pressure,
decreased. The tight closure prevented leakage of the
product, and the passage of air from outside to the
inside of the bottle. The high temperature might also
have reduced the stiffness of the polyethylene.

(Refer to Appendix B for further details on the 4 Liter
hot filled ketchup HDPE bottle).
(b) 1 Liter & 2 Liter floor cleaner HDPE bottles:

The paneling was observed a day after filling at the
factory warehouse during the outgoing inspection. Both
front and back label panels had deformed. The extent of
paneling was about 0.78 inch in length, 1.18 inches in
width and 0.39 inch in depth. The thickness of the bottle
wall where it had paneled was about 0.022 inch for the 1

liter bottle, and 0.031 inch for the 2 liter bottle.

13

According to the manufacturer, there was a
possibility of increase in the headspace volume which was
thought to be due to condensation of foam and the
permeation out of the bottle of product or components of
product. Since the cap had to be tightly Closed to
prevent the leakage of product and the passage of air
from outside to the inside of the bottle, should have
developed in the headspace.

(Refer to Appendix C for further details on the 1 Liter
and 2 liter floor cleaner HDPE bottles).
(c) 32 ounce cleaning product HDPE bottle:

Paneling was observed 1-2 weeks after filling. The
extent of paneling was about 3 inches in length and 2
inches in width. The thickness of the body wall where the
bottle had paneled was about 0.030 inch. Since the
products contained solvents and high fragrance, there was
a high possibility that product loss could have occurred
due to the permeation of these components. Initially,
these components would be absorbed into the walls.

They would then diffuse through the wall, and finally
evaporate from the outside surface. This would lead to an
increase in the headspace volume. Since the liner was
tightly sealed to prevent product leakage and air passage

from outside to the inside of the bottle, underpressure

14

could develop in the headspace. According to the
manufacturer, there was no oxidation since the product
would not react with oxygen in the headspace. The
temperature difference between the filling and storage
was about 8°F but this would not be significant in
causing underpressure in the headspace. There was
progressive (gradual increase in depth and extent)
paneling and a permanent distortion.
(Refer to Appendix D for further details on the 32 Ounce
cleaning product HDPE bottle).
(d) 24 ounce hot filled chocolate syrup HDPE bottle:

The paneling was observed immediately after filling.
The thickness of the body wall where the bottle had
paneled was 0.030 inch. According to the manufacturer,
there was 3% product volume shrinkage upon cooling. This

increased the headspace volume since the product was
filled at 185°F and cooled to a storage temperature of

60°F. By using the ideal gas law,

P1V1 P2V2

-—

anl nsz

 

a theoretical final pressure (P2) in the headspace can be
determined.
Overflow volume of the bottle = 20 £1.02.

Therefore, headspace volume (V1) = 1.54 £1.02

15

 

Volume of product with product density of 1.3
= 18.46 fl.oz.

Product shrunk by 3% and this was equal to 0.55 fl.oz.
Therefore new headspace (V;) = 1.54 + 0.55 = 2.09 fl.oz.

Initial and final volume of the air originally in
the headspace would remain the same if the container was
rigid and product volume did not change. The pressure in
the headspace would be reduced.

Product shrinkage of 3% upon cooling does increase
the headspace by 0.55 fl.oz. If the container was rigid,
the pressure would be further reduced.

Initial temperature (T1) = 273 + 185 = 458 K.
Final temperature (T2) = 273 + 60 = 333 K.

Assuming a hypothetical rigid container, the final
pressure (P2) inside the container would be:

P2=P1XV1XT2

 

 

I1 x v2
= 760 x 1.54 x 333
458 x 2.09
= 414.4 mmHg

This would create a pressure differential of 346 mmHg.

According to the manufacturer, the paneling occurred
immediately with cooling of the product to 60°F and
remained fixed. The paneling observed is presumed to be
the response of the semirigid container as the system

tends toward pressure equilibrium.

l6

It has been suggested that an additional factor
contributing to pressure differential would be
condensation of water vapor in the headspace. However,
this contribution is probably negligible.

(Refer to Appendix E for further details on the 24 ounce
hot filled chocolate syrup HDPE bottle).
(e) 1 liter hair root Lifter HDPE bottles:

The paneling was observed immediately after filling.
The thickness of the body wall where the bottle had
paneled was 0.018 inch. According to the manufacturer,
there was a possibility that the product reacted with
oxygen in the headspace, leading to underpressure in the
headspace. There was progressive paneling and permanent
distortion.

(Refer to Appendix F for further details on the 1 liter
hair root lifter HDPE bottles).
(f) Dietary supplements:

The paneling was observed 15-20 days after filling.
The thickness of the body wall where the body had paneled
was 0.0296 inch. The product reacted with oxygen in the
headspace (This was confirmed by the manufacturer's own
analysis). This led to vacuum and underpressure in the
headspace. Since the liner was tightly sealed to prevent

the passage of air from outside to the inside of the

17

bottle, underpressure developed in the headspace.

There was progressive paneling and permanent distortion.
(Refer to Appendix G for further details on the dietary
supplements).

Summary of field study:

The analysis of the field study on the above six
products showed that there was a possibility of development
of underpressure in the headspace. The possible causes of
underpressure were loss of product due to permeation out of
the bottle by product or components of the product, leading
to an increase in the volume in the headspace; reaction of
the product with the oxygen in the headspace, leading to
the removal of oxygen from the headspace; and the
contraction of hot filled products upon cooling, leading

to an increase in volume of the headspace in the bottle.

The pressure differential was assumed to have caused
immediate paneling (about 1-2 minutes, before packing
into the shipper, after filling) as.in the case of hot
filled chocolate syrup and hair root lifter or delayed
paneling (1-20 days) as in the case of hot filled
ketchup, cleaning products, floor cleaner and dietary
supplements. Paneling was observed to be a permanent

distortion in all six products.

18

After this field study, there was still a lack of
information about the causes of paneling. Therefore, an
experiment was designed to gather more information about
paneling. The experiment was carried out by evacuating air
from the headspace of bottles at room temperature and

observing the vacuum level required to deform the bottle.

The bottles used in the experiment were of the same
kind as those in the field study that contained dietary
supplement, shampoo, and hair care product.

The experiment was designed to verify,

(a) whether pressure differential could be the cause of
paneling;

(b) whether creep was influencing the paneling (Creep is
the time dependent increase in strain of a viscous or
visco-elastic material under sustained stress); and

(c) whether the thickness variation in the bottle wall was

influencing the paneling.

19

CHAPTER 3
Materials and Method
Introduction:-
A pressure differential was created between the inside and
the outside of the bottle by evacuating air from the
headspace inside the bottle. The objectives of this
experiment were to evaluate
(1) the vacuum level (and so the pressure differential)
required to deform the bottle;
(2) the influence of creep on paneling;
(3) the influence of thickness variation on paneling.
Materials:

1.Bottle samples
(a)Dietary Supplements:

 

White HDPE cylindrical bottle with diameter 2 3/4 inches
and height 5 3/8 inches was used for containing dietary
supplement tablets.
(b)Shampoo:
White HDPE cylindrical bottle with diameter 1 1/2 inches
and height 9 inches used for containing shampoo.
(c)Hair-care products:
Silk screen printed clear HDPE cylindrical bottle with
diameter 3 1/4 inches and height 9 5/8 inches used for
containing hair-care product.

2. Vacuum pump (Cenco Hyrac 2)

 

20

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

I3.Magna Mike (Model 8000; Hall effect thickness gauge;
sensitivity = +/- 0.00005 inch)

‘4.Vacuum gauge(GATT: 0—760 mmHg/O-3O ian;
sensitivity = +/— 5 mmHg / +/- 0.25 ian)

5. Needle valve (to control and maintain vacuum)

6. Water (used as product simulant for shampoo/hair care
product bottles)

7. Dietary supplement tablets (used for testing dietary
supplement bottles)

8. Suction flask (Kimax 1000 milliliter with side arm)

9. Vertical stand (metal)

10.Stop watch (Meylan 0—30 minutes; 1/100 of a minute)

11.Flexible connecting tubes (Tygon clear laboratory, R3503
with OD: 3/8; Rubber, thick wall with OD: 5/8)

l2.Rigid tube (Nalgene 689 Polypropylene with OD 1/4 inch)

13.Connector kit (straight polypropylene with OD: 3/8 inch)

14.Rubber stoppers (solid Neoprene for closing sample
bottles / suction flask)

15.Measuring rulers (6 inches / 12 inches in length)

16.Permanent marker pen

17.Rubber band

Method:

1. The testing was done by filling the bottle with water to

the fill level or by using the tablets in the dietary

21

supplement bottle, and subjecting it to vacuum. The
setup of the experiment is shown in Figure 3.

The sample bottle was first analyzed for variation in
thickness. A total of 16 points were measured on the
body of the bottle. This was done by making a reference
to direction and distance as described in Figure 4. The
directions, upper, right side, lower and left side were
determined clockwise by holding the bottle with the
plastic identification symbol facing upright and on the
right hand side. The distance of each point from the
bottom was measured from the heel.

The sample bottle was filled with water and the overflow
volume was recorded. The bottle was then emptied. For
shampoo and hair care products, the bottle was refilled
with water up to a volume of 90% of the overflow volume.
In the case of the dietary supplement products, 240
dietary supplement tablets were filled into the bottle.
The bottle was closed with a rubber stopper into which

was inserted a rigid tube as shown in Figure 5.

22

 

flexible tube

 

 

 

 

 

 

 

 

 

 

 

 

 
  
   

 

 

 

 

 

 

 

 

 

 

 

 

 

air let
vertical stand ‘(/// U vacuum gang.
/ D needle (mmHg/1339)
film ‘ valve
connectorH
rubber
stopper
. . dr've belt
rigi ‘2
tube
rubber
band
ottle A I
water or , T vacuum cord to
tablets 3°Ct1°n flask pumP’ power supply

Figure 3. _ Experiment - Vacuum Testing

23

4th point
3rd p}int

/ 2nd PO - nt
,,/”"I lst po'nt
u er
pinch
mark
shoulder
right
left EDPa side
Side
heel

 

lower

Figure 4. Measurement of the thickness of a
point on the body of the bottle

 

 

Figure 5. Test sample bottles

25

 

Figure 6. Experiment - dietary supplement
bottle

The sample bottle was secured to a vertical stand by
using a rubber band as shown in Figure 6. The sample
bottle was connected to the suction flask by a flexible
tube, which in turn is connected to a rigid tube by a
connector. The side arm of the suction flask was
connected to one end of the T-junction needle valve. The
needle valve was connected to the vacuum pump and vacuum
gauge.

The vacuum pump was started, and the needle valve was
closed slowly to increase the vacuum. When the bottle
began to deform to a depth of about 1/32 inch, the

approximate vacuum level was noted.

27

 

On the same bottle, the immediate paneling was found by
setting the vacuum level at intervals of 5 mmHg,
starting below 5—10 mmHg of the approximate vacuum level
at which the body wall first deformed. The 5 mmHg
increment was chosen because the gauge was graduated at
intervals of 10 mmHg. Therefore, a sensitivity of 5 mmHg
could be used. The vacuum was held for two minutes at
each 5 mmHg increment. Immediate paneling is defined as
the vacuum level required to deform the body of the
bottle to a depth of 1/32 of an inch within 2 minutes.

This is shown in Figure 7.

The same bottle was then maintained at the immediate
paneling vacuum level. The stopwatch was started. The
depth of paneling was measured with a ruler by aligning
the ruler against the edge of the vertical stand. As the
depth of paneling increased, the measuring ruler was
moved against the body of the bottle, accordingly. When
the measuring ruler read 1/8 inch and 1/4 inch, their
supplement bottle, and subjecting it to vacuum. The
respective approximate timings were recorded. The extent
of deformation of each of the three bottles at a depth
of paneling of 1/8 inch and 1/4 inch are shown in

Figures 8 to 13. When the bottle started to panel to a

28

depth of 1/4 inch, the approximate center of paneling
was marked, using a permanent marker pen. The thickness

of the center of paneling was measured later.

29

 

Figure 7. Deformation by 1/32 of an inch

30

 

Figure 8. Dietary supplements - depth of
paneling of 1/8 inch

31

 

 

 

Figure 9. Dietary supplement bottle —

depth of paneling of 1/4 inch

32

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36

CHAPTER 4
Data and Results

All three bottles (shampoo, dietary supplements and
hair care products) had varying thickness (axially and
circumferentially) of the body wall as shown in Tables 2, 3
and 4. The thickness of the body wall measured from 0.0305
inch to 0.0528 inch for shampoo bottles, 0.0345 inch to
0.0503 inch for dietary supplement bottles and from 0.0295
inch to 0.0434 inch for the hair care product bottles.

The average wall thicknesses around the circumference
for samples of the three bottles are shown in Tables 5, 6
and 7. In the case of shampoo bottles, all samples have
shown a decrease in thickness from the heel to the shoulder
of the bottle. For dietary supplement bottles, 7 of the 10
samples measured initially showed an increase in thickness
and then a decrease in thickness from the heel to the
shoulder of the bottle. For hair care product bottles, all
samples have shown a decrease in thickness from the heel to

the shoulder of the bottle.

The vacuum ranges required to panel shampoo bottles,
dietary supplement bottles and hair care product bottles
were 150—165 mmHg, 220-230 mmHg and 40-55 mmHg respectively
as shown in Tables 8, 9 and 10. The differences in vacuum

levels between these three bottles are substantial. There

37

 

Table 2. Shampoo bottles - Body thickness measurements, inches

 

 

 

 

 

 

Samples Directions 1st point 2nd point 3rd point 4th point
* ** At 1.5" At 3" At 4.5" At 6"

01-81 Upper 0.0445 0.0395 0.0382 0.0343
Right side 0.0490 0.0528 0.0408 0.0378
Lower 0.0420 0.0406 0.0379 0.0341
Left side 0.0422 0.0378 0.0356 0.0330
C1 -82 Upper 0.0447 0.0400 0.0395 0.0354
Right side 0.0492 0.0493 0.0405 0.0372
Lower 0.0420 0.0412 0.0375 0.0337
Left side 0.0429 0.0389 0.0368 0.0336
02-81 Upper 0.0420 0.0397 0.0362 0.0324
Right side 0.0436 0.0495 0.0352 0.0305
Lower 0.041 7 0.0389 0.0360 0.0321
Left side 0.0451 0.0413 0.0385 0.0355
02-82 Upper 0.0468 0.0440 0.0407 0.0350
Right side 0.0467 0.0522 0.0371 0.0330
Lower 0.0427 0.0407 0.0396 0.0344
Left side 0.0482 0.0454 0.0425 0.0377

 

 

 

 

 

 

* A sample is identified by cavity number and sample number.
Example, C1-S1 refers to sample number 1 of cavity number 1.
** The direction is made in reference to Figure 4, Chapter 3.

38

 

Table 3. Dietary suplement bottles - Body thickness measurements, Inches

 

 

 

 

 

 

 

 

 

 

 

 

 

Samples Directions 1st point 2nd point 3rd point 4th point
* ** At 0.75" At 1.5" At 2.25" At 3"
C1 -81 Upper 0.0422 0.0445 0.0412 0.0381
Right side 0.0422 0.0416 0.0482 0.0373
Lower 0.0434 0.0445 0.0425 0.0385
Left side 0.0462 0.0503 0.0472 0.0395
C1-82 Upper 0.0435 0.0460 0.0455 0.0393
Right side 0.0343 0.0436 0.0434 0.0376
Lower 0.0434 0.0473 0.0461 0.0375
Left side 0.0492 0.0496 0.0464 0.0393
02-81 Upper 0.0345 0.0437 0.0430 0.0377
Right side 0.0461 0.0466 0.0458 0.0397
Lower 0.0409 0.0418 0.0430 0.0388
Left side 0.0458 0.0493 0.0472 0.0393
02-82 Upper 0.0437 0.0433 0.0430 0.0372
Right side 0.0471 0.0468 0.0462 0.0406
Lower 0.0418 0.0423 0.0430 0.0385
Left side 0.0463 0.0481 0.0472 0.0392
C3-S1 Upper 0.0370 0.0392 0.0404 0.0358
Right side 0.0478 0.0492 0.0491 0.0416
Lower 0.0480 0.0493 0.0492 0.0431
Left side 0.0423 0.0444 0.0456 0.0413
03-82 Upper 0.0389 0.0397 0.0396 0.0352
Right side 0.0465 0.0476 0.0478 0.0416
Lower 0.0433 0.0456 0.0471 0.0381
Left side 0.0450 0.0469 0.0475 0.0410
C4-S1 Upper 0.0423 0.0441 0.0451 0.0389
Right side 0.0492 0.0481 0.0461 0.0402
Lower 0.0437 0.0441 0.0432 0.0395
Left side 0.0430 0.0441 0.0436 0.0381
04-82 Upper 0.0406 0.0435 0.0449 0.0365
Right side 0.0477 0.0475 0.0466 0.0388
Lower 0.0437 0.0434 0.0434 0.0370
Left side 0.0442 0.0432 0.0434 0.0375
05-81 Upper 0.0440 0.0468 0.0466 0.0387
Right side 0.0481 0.0491 0.0453 0.0385
Lower 0.0442 0.0462 0.0456 0.0387
Left side 0.0405 0.0438 0.0441 0.0377
05-82 Upper 0.0430 0.0464 0.0461 0.0402
Right side 0.0500 0.0498 0.0460 0.0384
Lower 0.0442 0.0466 0.0468 0.0393
Left side 0.0402 0.0434 0.0437 0.0376

 

 

 

 

 

 

* A sample is identified by cavity number and sample number.
Example, C1-S1 refers to sample number 1 of cavity number 1.
** The direction is made in reference to Figure 4. Chapter 3.

39

 

Table 4. Hair Care Product bottles - Body thickness measurements, inches

 

 

 

 

 

 

 

 

 

 

 

 

Samples Directions 1st point 2nd point 3rd point 4th point
* ** At 2" At 3.5” At 5" At 6.5"
01-81 Upper 0.0400 0.0380 0.0409 0.0384
Right side 0.0418 0.0379 0.0359 0.0363
Lower 0.0433 0.0366 0.0368 0.0332
Left side 0.0375 0.0329 0.0324 0.0309
C1-82 Upper 0.0399 0.0382 0.0398 0.0353
Right side 0.0434 0.0402 0.0380 0.0357
Lower 0.0416 0.0370 0.0346 0.0332
Left side 0.0384 0.0338 0.0349 0.0332
02-81 Upper 0.0380 0.0390 0.0344 0.0352
Right side 0.0450 0.0403 0.0386 0.0369
Lower 0.0440 0.0376 0.0360 0.0332
Left side 0.0396 0.0344 0.0332 0.0319
02-82 Upper 0.0389 0.0386 0.0396 0.0353
Right side 0.0418 0.0404 0.0401 0.0364
Lower 0.0422 0.0370 0.0355 0.0323
Left side 0.0382 0.0332 0.0318 0.0311
03-81 Upper 0.0430 0.0402 0.0402 0.0390
Right side 0.0442 0.0368 0.0370 0.0354
Lower 0.0418 0.0358 0.0350 0.0320
Left side 0.0400 0.0344 0.0336 0.0328
03-82 Upper 0.0398 0.0387 0.0377 0.0355
Right side 0.0416 0.0381 0.0372 0.0353
Lower 0.0415 0.0371 0.0355 0.0324
Left side 0.0378 0.0338 0.0326 0.0309
04-81 Upper 0.0430 0.0375 0.0375 0.0384
Right side 0.0441 0.0400 0.0386 0.0362
Lower 0.0439 0.0365 0.0364 0.0323
Left side 0.0397 0.0334 0.0321 0.0308
04-82 Upper 0.0410 0.0382 0.0376 0.0350
Right side 0.0440 0.0392 0.0382 0.0354
Lower 0.0402 0.0352 0.0352 0.031 1
Left side 0.0380 0.0330 0.0326 0.0301
05-81 Upper 0.041 1 0.0386 0.0376 0.0360
Right side 0.0423 0.0397 0.0375 0.0360
Lower 0.0428 0.0376 0.0345 0.0323
Left side 0.0397 0.0358 0.0344 0.0332

 

 

 

 

 

 

40

 

 

Table 4. (Continued)

 

 

 

 

 

 

 

 

 

 

 

Samples Directions 1st point 2nd point 3rd point 4th point
* ** At 2" At 3.5" At 5" At 6.5"
C5-82 Upper 0.0395 0.0369 0.0356 0.0340
Right side 0.0415 0.0396 0.0385 0.0371
Lower 0.0392 0.0357 0.0338 0.0319
Left side 0.0352 0.0329 0.0318 0.0295
C6-81 Upper 0.0433 0.0412 0.0395 0.0391
Right side 0.0421 0.0422 0.0375 0.0358
Lower 0.0426 0.0373 0.0345 0.0331
Left side 0.0387 0.0349 0.0320 0.0309
06-82 Upper 0.0392 0.0373 0.0345 0.0344
Right side 0.0415 0.0397 0.0382 0.0384
Lower 0.0405 0.0359 0.0333 0.0331
Left side 0.0361 0.0338 0.0303 0.0331
C7-81 Upper 0.0440 0.0392 0.0368 0.0351
Right side 0.0428 0.0385 0.0364 0.0361
Lower 0.0421 0.0362 0.0338 0.0323
Left side 0.0382 0.0336 0.0324 0.0311
C7-82 Upper 0.0391 0.0375 0.0361 0.0353
Right side 0.0426 0.0396 0.0393 0.0356
Lower 0.0422 0.0366 0.0344 0.0326
Left side 0.0377 0.0335 0.0325 0.0315
08-81 Upper 0.0382 0.0373 0.0361 0.0461
Right side 0.0332 0.0361 0.0293 0.0331
Lower 0.0366 0.0370 0.0330 0.0402
Left side 0.0376 0.0380 0.0360 0.0420
08-82 Upper 0.0430 0.0390 0.0365 0.0431
Right side 0.0341 0.0367 0.0306 0.0348
Lower 0.0380 0.0378 0.0348 0.0421
Left side 0.0382 0.0367 0.0352 0.0420
C9-S1 Upper 0.0404 0.0405 0.0371 0.0397
Right side 0.0415 0.0397 0.0396 0.0362
Lower 0.0424 0.0380 0.0350 0.0340
Left side 0.0370 0.0352 0.0335 0.0332
09-82 Upper 0.0409 0.0414 0.041 1 0.0392
Right side 0.0432 0.0403 0.0402 0.0390
Lower 0.0432 0.0357 0.0347 0.0322
Left side 0.0380 0.0342 0.0333 0.0320

 

 

 

 

 

 

A sample is identified by cavity number and sample number.

Example, C1-81 refers to sample number 1 of cavity number 1.
** The direction is made in reference to Figure 4, Chapter 3.

41

 

 

 

 

Table 5. Shampoo bottles-Average body thickness measured circumferentially
from heel to shoulder, inches

 

 

 

 

 

 

 

 

 

 

Samples 1st point 2nd point 3rd point 4th point
At 1.5” At 3" At 4.5" At 6"
01-81 0.0444 0.0427 0.0381 0.0348
01-82 0.0447 0.0424 0.0386 0.0350
02-81 0.0431 0.0424 0.0365 0.0326
02-82 0.0461 0.0456 0.0400 0.0350

 

Table 6. Dietary supplement bottles-Average body thickness measured
circumferentially from heel to shoulder, inches

 

 

 

 

 

 

 

 

 

 

 

 

Samples 1st point 2nd point 3rd point 4th point

At 0.75" At 1.5" At 2.25” At 3"
01-81 0.0435 0.0452 0.0448 0.0384
01-82 0.0426 0.0466 0.0454 0.0384
02-81 0.0418 0.0454 0.0448 0.0389
02-82 0.0447 0.0451 0.0449 0.0389
03-81 0.0438 0.0455 0.0461 0.0405
03-82 0.0434 0.0450 0.0455 0.0390
04-81 0.0446 0.0451 0.0445 0.0392
04-82 0.0441 0.0444 0.0446 0.0375
05-81 0.0442 0.0465 0.0454 0.0384
05-82 0.0344 0.0466 0.0457 0.0389

 

 

 

 

 

Table 7. Hair care product bottles-Average body thickness measured

circumferentially from heel to shoulder, inches

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Samples 1st point 2nd point 3rd point 4th point

At 2" At 3.5” At 5" At 6.5”
01-81 0.0407 0.0364 0.0365 0.0347
01-82 0.0408 0.0373 0.0368 0.0344
02-81 0.0417 0.0378 0.0356 0.0343
02-82 0.0403 0.0373 0.0368 0.0338
03-81 0.0423 0.0373 0.0365 0.0348
03-82 0.0402 0.0369 0.0358 0.0335
04-81 0.0427 0.0369 0.0362 0.0344
04-82 0.0408 0.0364 0.0359 0.0329
05-81 0.0415 0.0379 0.0360 0.0344
05-82 0.0389 0.0363 0.0349 0.0331
06-81 0.0417 0.0389 0.0359 0.0347
06-82 0.0393 0.0367 0.0341 0.0348
07-81 0.0418 0.0369 0.0349 0.0337
07-82 0.0404 0.0368 0.0356 0.0338
08-81 0.0364 0.0371 0.0336 0.0404
08-82 0.0377 0.0376 0.0343 0.0405
09-81 0.0403 0.0384 0.0363 0.0358
09-82 0.0413 0.0379 0.0373 0.0356

 

 

 

 

 

42

 

 

 

was paneling in two places on the shampoo bottle, three
places on the dietary supplement bottle and in a single
place on the hair care product bottles.

The time required to panel the bottle to depths of 1/8
inch and 1/4 inch are also shown in Tables 8, 9 and 10. The
vacuum and time ranges required to panel the shampoo
bottles, dietary supplement bottles and hair care product
bottles to a depth of 1/8 inch and 1/4inch are shown in
Table 11.

For all three bottles, the time required to deform to
1/4 inch from 1/8 inch was very short compared to the time
required to deform from 1/32 inch to 1/8 inch.

Figures 14, 15 and 16 show the location of paneling at
maximum depth on the body wall for shampoo bottle, dietary
supplement bottle and hair care product bottle
respectively. These figures also show thickness of the
body of the bottle where the maximum depth of paneling had
taken place.

For shampoo bottles, the location of paneling is above
the mid-point of the body height of 7 inches. The location
of paneling was between 3.75 inches and 4.75 inches. The
location of paneling for cavity one is higher than cavity
two. These locations are in the region of the thinner

section of the body wall.

43

Table 8. Shampoo bottles - Vacuum testing values and time taken to panel

 

 

 

 

Samples Vacuum to cause Time taken to panel depth Time taken to panel
immediate paneling 1/8" at same vacuum depth 1/4" at same
(mmHg) (min) vacuum (min)
01-81 160 30.1 30.2
01-82 155 12.4 12.5
02-81 150 61.7 61.8
02-82 165 81.5 87.4

 

 

 

 

 

 

Table 9. Dietary Supplement bottles - Vacuum testing values and time

taken to panel

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Samples Vacuum to cause Time taken to panel depth Time taken to panel
immediate paneling 1/8" at same vacuum depth 1/4" at same
(mmHg) (min) vacuum (min)
01- 81 230 45.1 45.3
01- 82 220 62.7 63.3
02-81 230 51 .2 51 .7
02-82 230 63.7 63.9
03—81 230 51.5 51.7
03-82 230 25.0 25.2
04-81 220 37.3 37.5
04-82 220 32.4 32.8
05-81 230 73.4 73.6
05—82 230 33.5 33.7
Table 10. Hair Care Product bottles - Vacuum testing values and time taken
to panel
Samples Vacuum to cause Time taken to panel depth Time taken to panel
immediate paneling 1/8" at same vacuum depth 1/4" at same
(mmHg) (min) vacuum (min)
01- 81 40 12.8 13.2
01- 82 45 20.7 21.6
02-81 45 23.0 23.9
02-82 55 9.7 10.0
03-81 55 6.5 6.7
03-82 50 5.7 5.9
04-81 45 13.5 13.9
04-82 50 3.7 3.9
05-81 45 16.8 17.3
05-82 45 4.4 4.6
06-81 40 22.3 22.6
06-82 40 17.7 18.2
07-81 45 15.8 16.1
07-82 45 5.6 6.0
08-81 40 19.6 20.0
08-82 45 17.4 17.6
09-81 45 14.5 14.9
09-82 45 12.5 12.9

 

44

 

 

 

Table 11. Vacuum and time ranges required to panel

 

 

 

 

 

 

 

Bottles Vacuum to cause Time range to Time range to
immediate panel depth 1/8" panel depth 1/8"
paneling (mmHg) (min) (min)
Shampoo 150-165 12.4-81.5 0.1 *
Dietary supplement 220-230 25-73.4 0206
Hair care product 40-55 3.7-22.3 0.2-0.9

 

 

 

 

* Except for sample 02-82 which took 5.9 minutes

45

 

Samples 1st point 2nd point 3rd point 4th point

 
     

At 1 .5" At 3" At 4.5" At 6"
C1 -S1 0.0444 0.0427 0.0381 At 4.625 0.0348
C1 -82 0.0447 0.0424 0.0386 At 4.75 0.0350
C2-Sl 0.0431 0.0424 0.0365 0.0326
CZ-SZ 0.0461 0.0456 0.0400 0.0350

 

Note : 1 Flat body height of the bottle = 7"
-Location of paneling and thickness of the body where maximum
depth of paneling had taken place

Figure 14. Mapping of paneling : Shampoo bottles
Location of paneling and wall thicknesses are shown inside the
heavy lines. Four points (1.5 ", 3", 4.5" and 6") are the distances
above the heel (see Figure 4). The other values are the average
wall thicknesses at that height above the heel.

46

 

 

 

 

 

 

 

 

 

 

 

 

 

Samples 1st point 2nd point 3rdpoint 4th point
At 0.75 At 1.5" At 2.25" At 3"

01-81 0.0435 0.0452 At 2" 0.0448 0.0384
0.0409

01-82 0.0426 0.0466 At 2" 0.0454 0.0384
0.0425

02-81 0.0418 0.0454 At 2" 0.0448 0.0389
0.0417

02-82 0.0447 0.0451 At 2" 0.0449 0.0389
0.0383

03-81 0.0438 0.0455 At 2" 0.0461 0.0405
0.0399

03—82 0.0434 0.0450 At 2" 0.0455 0.0390
0.0405

04-81 0.0446 0.0451 At 2" 0.0455 0.0392
0.0446

04-82 0.0441 0.0444 At 2" 0.0446 0.0375
0.0436

05-81 0.0442 0.0465 At 2.125" 0.0454 0.0384
0.0422

05-82 0.0344 0.0466 At 2.125" 0.0457 0.0389
0.0421

Note: 1 F lat body height of the bottle = 3.5"

 

21 |Location of paneling and thickness of the body where maximum
depth of paneling had taken place

Figure 15: Mapping of paneling : Dietary supplement bottles
Location of paneling and wall thicknesses are shown inside the
heavy lines. Four points (1.5", 3", 4.5" and 6") are the distances
above the heel (see Figure 4). The other values are the average
wall thicknesses at that height above the heel.

47

  

 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Samples 1st point 2nd point 3rd point 4th point
At 2" At 3.5” At 5" At 6.5”
01-81 0.0407 0.0364 0.0365 ‘ At 5.25" 0.0347
0.031

01-82 0.0408 0.0373 0.0360 At 5" 0.0344
0.0325

02-81 0.0417 0.0378 0.0356 At 5" ‘ 0.0343
0.0356

02-82 0.0403 0.0373 0.0368 At 5" 0.0338
0.0316

03-81 0.0423 0.0373 0.0365 At 5" 0.0348
‘ 0.0311

03-82 0.0402 0.0369 0.0358 At 5" 0.0325
0.0334

04-81 0.0427 0.0369 0.0362 At 5" 0.0344
0.0324

04-82 0.0408 0.0364 0.0359 At 5" 0.0329
0.0333

.—

0581 0.0415 0.0379 0.0360 At 5.25" 0.0344
0.0324

05-82 0.0389 0.0363 0.0349 At 5" ‘ 0.0331
0.0332

06-81 0.0417 0.0389 0.0359 At 5.25” 0.0347
0.0310

06-82 0.0393 0.0367 0.0341 At 5.25" 0.0348
0.0300

07-81 0.0418 0.0369 0.0349 At 5.25" 0.0337
0.0346

07-82 0.0404 0.0368 0.0356 At 5.25” 0.0338
0.0318

08-81 0.0364 0.0371 At 4.75" 0.0336 0.0404

08-82 0.0377 0.0376 0.0343 0.0405

0.0289
09-81 0.0403 0.0384 0.0363 0.0358
09-82 0.0413 0.0379 0.0373 0.0356
Note:

1 Flat bod height of the bottle = 7.5"
Zémcation of paneling and thicknessof the body where maximum

depth of paneling had taken place

Figure 16. Mapping of paneling : Hair care product bottles
Location of paneling and wall thicknesses are shown inside the
heavy lines. Four points (1.5”, 3", 4.5" and 6") are the
distances above the heel (see Figure 4). The other values
are the average wall thicknesses at that height above the heel.

48

For dietary supplement bottles, the location of
paneling is 0.25 inch above the mid—point of the body
height of 3.5 inches.

For hair care product bottles, the location of
paneling is above the mid-point of the body height of 7.5
inches. The location of paneling was between 4.75 inches
and 5.25 inches. The location of paneling of cavity eight
is lower than the other cavities. These locations are in
the region of the thinner section of the body.

The vacuum level of 40-55 mmHg to cause paneling of
hair care product bottles was much lower than the partial
pressure of atmospheric oxygen (159.5 mmHg). The vacuum
level of 150-165 mmHg to cause the paneling of shampoo
bottles was almost the same as the partial pressure of
atmospheric oxygen. The vacuum level of 220-230 mmHg to
cause the paneling of dietary supplement bottles was
higher than the partial pressure of atmospheric oxygen.

A dietary supplement bottle that had paneled with
product in it was evaluated to determine whether pressure
differential due to the removal of oxygen from the
headspace could be the cause of paneling. Removal of oxygen
by the product had been suggested as a cause of paneling.

The calculations are as follows:

49

Overflow volume of the deformed bottle was 413 ml.
Total volume of the product was 314 ml.

Therefore, the headspace volume of the deformed bottle
was 99ml (413—314).

Overflow volume of an undeformed bottle was 430 ml.

Therefore, the headspace volume of the undeformed
bottle was 116 ml (430-314).

So the reduction in the headspace volume as a result of
deformation was 17 ml (116-99).

If all the oxygen from the original headspace was
removed without changing the headspace volume, then the
pressure would drop to 600 mmHg (79% of 760 mmHg), thus
allowing the headspace volume to shrink until the pressure
goes back to 760 mmHg. Oxygen occupied 21% of 116 ml, which
is equal to 24 ml. So, if there is a complete removal of
oxygen, the headspace volume would drop by 24 ml.

Sorption of 71% (17/24 X 100%) of oxygen in the
headspace could account for the volume change. Therefore,
the pressure of oxygen in the container would have been
113.32 mmHg (760 mmHg X 0.21 X 0.71). The headspace in the
container would have nitrogen at 600 mmHg (0.78 x 760 mmHg)
and oxygen at 113 mmHg for a total of 713 mmHg internal
pressure. This would have caused a pressure differential
of 47 mmHg between inside and outside of the container,

thus causing the container to panel.

50

CHAPTER 5
Conclusion and Future Work

The experiments on vacuum evacuation of shampoo,
dietary supplements and hair care product bottles showed
that a pressure differential is one of the possible causes
of paneling of the bottle. The creep (the time dependent
increase in strain under sustained stress) can influence
the paneling significantly. The location of paneling where
the paneling has reached a maximum depth showed that its
location is above the mid-point of the flat body height for
shampoo bottles and hair care product bottles. However,
there was no indication of the influence of thickness
variation on paneling.

A possible cause of underpressure in the headspace
for all three bottles (shampoo, dietary supplement and hair
care product) was removal of oxygen. The maximum pressure
differential would be about 160 mmHg, if all the oxygen
were removed from the headspace. This could have been the
case for the hair care product and the shampoo product.
However, in the case of dietary supplement, the vacuum
level of 220-230 mmHg required to panel the bottle is
greater than the pressure differential resulting from

removal (sorption) of oxygen.

51

All three products showed that the creep had

significantly influenced paneling. As mentioned in

Chapter 4, all three bottles took a long time to panel

from a depth of 1/32 inch to a depth of 1/8 inch and a very
short time to panel from 1/8 inch to a depth of 1/4 inch.

It can be said that the two factors, i.e. pressure
differential and creep, played a combined role rather than
an individual role in causing the paneling of plastic
bottles.

The manufacturer’s request for a solution to the
paneling problem can be approached by using the questions
guide mentioned in Appendix A. With this guide we will be
able to analyze the causes of paneling and develop an
appropriate solution to solve the paneling problem.

The design of the bottle is also important to minimize
or avoid paneling. The design includes the size, shape and
thickness distribution. The bottle may be made more
resistant to deformation by incorporating stress absorbing
strips as described in Chapter 1 (literature review)

The vacuum test can be used to evaluate the resistance
of bottles to paneling, during the development of new
packages. It also can be used to check incoming quality
control based on sampling, to ensure that the bottles will

not panel after filling, until sold.

52

A study is needed to evaluate the influence of
thickness variation on paneling. Therefore, future study
on paneling of plastic bottles may include the following
areas:

The influence of thickness variation on paneling.

(1) The influence of temperature on paneling.

(2) The determination of the percentage of oxygen in the
headspace of the paneled bottles.

(3) The determination of the increase in volume in the
headspace, due to reduction in the volume of the
product. (This may be caused by product loss through
permeation or by product shrinkage, which may have
occurred when the product was filled at high

temperature, followed by cooling to room temperature).

53

APPENDIX A
Question Guide for Analyzing the Causes of Paneling in

the field

54

Product:-

1) Type of product

2) Volume of shrinkage upon contraction

3) Reaction with oxygen in the headspace

4) Permeation of product/components through the bottle
wall

Bottle:-

1) Material

2) Dimensions and shape

3) Thickness of the body wall

4) Type of closure

5) Type of sealing at the finish

6) Overflow volume

Filling:-

1) Type of filling

2) Temperature during filling

3) Foaming of product during filling

4) Headspace volume

5) Method of capping

6) Time lapse for packing the finished bottles into

the shipper

55

Storage and Distribution:-

1) Type of secondary packaging

2) Type of pallet stacking pattern

3) Storage time of the finished products at the
warehouses (factory, distribution and customer)

4) Temperature at the warehouses (factory, distribution

and customer)

Paneling:-

1) Location

2) Shape and the magnitude

3) Percentage of paneling in a lot
4) Progressive or sudden collapse
5) Thickness of the section

6) Design of the section

7) Permanency of the distortion

8) Time elapsed after filling

9) Fixed or increased with time

10) Place first observed

56

APPENDIX B

4 Liter hot filled Ketchup HDPE bottle

57

Product:-

1) Type of product: Ketchup

2) Volume of shrinkage upon contraction: Not known

3) Reaction with oxygen in the headspace: NOne

4) Permeation of product/components through the bottle

wall: Water

Bottle:-

1) Material: High density polyethylene

2) Dimensions: diameter -about 5.90 inches
body height-about 5.90 inches
conical shoulder with hollow handle about
3.14 inches

3) Thickness of the body wall: 0.039-0.043 inch

4) Type of closure: screw on polypropylene cap with low

density polyethylene inner plug

5) Type of sealing at the finish: NOne

6) Overflow volume: about 4320 milliliters

Filling:-

1) Type of filling: Vblumetric

2) Temperature during filling: l40°F

3) Foaming of product during filling: None

4) Headspace volume: about 320 milliliters

58

5) Method of capping: Manual inner plug insertion
followed by semi-automatic

punching; manual capping

6) Time lapse for packing the finished bottles into

the shipper: Packed immediately

Storage and Distribution:-
1) Type of secondary packaging: RSC
2) Type of pallet stacking pattern: Block pattern with no
space in between
3) Storage time of the finished products at the
warehouses: Factory : 3 days
Distribution: 15-30 days

Customer : 15-30 days

4) Temperature at the warehouses: Factory : 80-100°F

Distribution: 80-115°F

Customer : 80-100°F

Paneling:-

1) Location: Mid section of the body wall

2) Shape and the magnitude: Indented
Length: 1.18 inches
Width : 1.81 inches

Depth : 0.39 inch

59

10)

Percentage of paneling in a lot: 100%
Progressive or sudden collapse: Progressive
Thickness of the section: 0.039 inch
Design of the section: Segment of a circle
Permanency of the distortion: Permanent
Time elapsed after filling: about a week
Fixed or increased with time: Increased

Place first observed: Food service outlets

6O

APPENDIX C

1 Liter and 2 Liter floor cleaner HDPE bottle

61

Product:-

1) Type of product: Floor cleaner

2) Volume of shrinkage upon contraction: NOne
3) Reaction with oxygen in the headspace: None
4) Permeation of product/components through the bottle

wall: Solvent and Fragrance

Bottle: -
1) Material: High density polyethylene
2) Dimensions: 1 Liter : Length -about 5.90 inches
Width -about 5.90 inches
Height -about 8.66 inches
2 Liter : Length -about 3.93 inches
Width -about 3.14 inches
Height -about 10.23 inches
3) Thickness of the body wall: 1 Liter : 0.027 inch
2 liter : 0.031 inch
4) Type of closure: screw on polypropylene cap with
inner sealing ring
5) Type of sealing at the finish: None
6) Overflow volume: 1 Liter : about 1080 milliliters

2 Liter : about 2160 milliliters

Filling:-

1) Type of filling: Pressure

62

Temperature during filling: 70°F
Foaming of product during filling: Foam.filled the
headspace
Headspace volume: 1 Liter : about 80 milliliters
2 Liter : about 160 milliliters
Method of capping: Manual cap loading followed by

automatic in-line belt wheel

Time lapse for packing the finished bottles into

the shipper: Packed immediately

Storage and Distribution:-

1) Type of secondary packaging: RSC
2) Type of pallet stacking pattern: Interlock pattern with
no space in between
3) Storage time of the finished products at the
warehouses: Factory : 3 days
Distribution: 30 days
Customer : 30 days
4) Temperature at the warehouses: Factory : 80-100°F
Distribution: 80-115°F
Customer : 80-100°F
Paneling:-
1) Location: Front and back label panels
2) Shape and the magnitude: Indented

63

10)

Length: 1.18 inches

Width . 0.78 inches
Depth : 0.19 inch
Percentage of paneling in a lot: 100%

Progressive or sudden collapse: Progressive

Thickness of the section: 1 Liter : 0.021 inch
2 liter : 0.031 inch

Design of the section: Flat panel

Permanency of the distortion: Permanent

Time elapsed after filling: About 3 hours

Fixed or increased with time: Increased

Place first observed: Factory warehouse

APPENDIX D

32 Ounce cleaning product HDPE bottle

65

Product:-

1) Type of product: Cleaner product
2) Volume of shrinkage upon contraction: None
3) Reaction with oxygen in the headspace: None
4) Permeation of product/components through the bottle
wall: Solvent and Fragrance
Bottle:-
1) Material: High density polyethylene
2) Dimensions: diameter - 3.62 inches
height - 8.93 inches
3) Thickness of the body wall: 0.03 inch
4) Type of closure: screw on polypropylene cap with
0.04 inch F-127 PE foam liner
5) Type of sealing at the finish: None
6) Overflow volume: about 35 ounces
Filling:-
1) Type of filling: Piston volumetric
2) Temperature during filling: 80°F
3) Foaming of product during filling: Some products
foamed
4) Headspace volume: 8.5%
5) Method of capping: In-line spindle/wheel

66

6) Time lapse for packing the finished bottles into

the shipper: Packed immediately

Storage and Distribution:-
1) Type of secondary packaging: R80
2) Type of pallet stacking pattern: Column stacking
pattern
3) Storage time of the finished products at the
warehouses: Factory : 15-30 days
Distribution: 30-60 days

Customer : 5-10 days

4) Temperature at the warehouses: Factory : 72°F
Distribution: 72-110°F

Customer : 72°F

Paneling.-
1) Location: Mid section of the bottle
2) Shape and the magnitude: Indented
Length: 3 inches
Width : 2 inches
3) Percentage of paneling in a lot: 100%
4) Progressive or sudden collapse: Progressive
5) Thickness of the section: 0.030 inch

6) Design of the section: Segment of circle

67

7) Permanency of the distortion: Permanent
8) Time elapsed after filling: 1-2 weeks
9) Fixed or increased with time: Increased

10) Place first observed: Factory warehouse

68

APPENDIX E

24 Ounce hot filled chocolate syrup HDPE bottle

69

Product:-

1) Type of product: Hot filled chocolate syrup
2) Volume of shrinkage upon contraction: 3%
3) Reaction with oxygen in the headspace: None
4) Permeation of product/components through the bottle
wall: Water
Bottle:-
1) Material: High density polyethylene
2) Dimensions: Length - 4.5 inches
Width - 5.98 inches
Height - 7.75 inches
3) Thickness of the body wall: 0.020 - 0.060 inch
4) Type of closure: Push-pull cap
5) Type of sealing at the finish: None
6) Overflow volume: about 20 ounces
Filling:-
1) Type of filling: Volumetric
2) Temperature during filling: 185°F
3) Foaming of product during filling: None
4) Headspace volume: 8%
5) Method of capping: Rotating mechanical 3 finger

capper with three heads

70

6) Time lapse for packing the finished bottles into

the shipper: Not packed immediately

Storage and Distribution:-
1) Type of secondary packaging: R80
2) Type of pallet stacking pattern: Column stacking
pattern
3) Storage time of the finished products at the
warehouses: Factory : 12 weeks
Distribution: N/A
Customer : N/A
4) Temperature at the warehouses: Factory : 60°F
Distribution: N/A

Customer : N/A

Paneling:-

1) Location: Front and back label panels

2) Shape and the magnitude: Indented
Length: N/A

Width N/A

Depth : N/A
3) Percentage of paneling in a lot: 80%
4) Progressive or sudden collapse: Sudden collapse
5) Thickness of the section: 0.03 inch

6) Design of the section: Oval

7]

7) Permanency of the distortion: Permanent
8) Time elapsed after filling: Immediately
9) Fixed or increased with time: Fixed

10) Place first observed: Filling line

72

APPENDIX F

1 Liter hair root lifter HDPE bottle

73

Product:-

1) Type of product: Hair care product
2) Volume of shrinkage upon contraction: ane
3) Reaction with oxygen in the headspace: Possible
4) Permeation of product/components through the bottle
wall: Water
Bottle:-
1) Material: High density polyethylene
2) Dimensions: diameter - 3.25 inches
height - 9.65 inches
3) Thickness of the body wall: 0.018 inch
4) Type of closure: 33 nullimeters/415 polystyrene
polycam. dispensing closure
5) Type of sealing at the finish: None
6) Overflow volume: 1088 milliliters
Filling:-
1) Type of filling: Piston volumetric
2) Temperature during filling: 72°F
3) Foaming of product during filling: Foamed very little
4) Headspace volume: 8%
5) Method of capping: In-line belt/wheel
6) Time lapse for packing the finished bottles into

the shipper: Packed immediately

74

Storage and Distribution:-

1) Type of secondary packaging: RSC
2) Type of pallet stacking pattern: Interlock stacking
pattern
3) Storage time of the finished products at the
warehouses: Factory : 2 weeks
Distribution: 1-2 years
Customer : 1 year
4) Temperature at the warehouses: Factory : 72°F
Distribution: 72-110°F
Customer : 72°F
Paneling:-
1) Location: Mid section of the bottle
2) Shape and the magnitude: Indented
Length: N/A
Width : N/A
3) Percentage of paneling in a lot: 100%
4) Progressive or sudden collapse: Progressive
5) Thickness of the section: 0.018 inch
6) Design of the section: Segment of circle
7) Permanency of the distortion: Permanent
8) Time elapsed after filling: Immediately
9) Fixed or increased with time: Increased
10) Place first observed: Filling line

75

APPENDIX G

HDPE bottle containing 240 Dietary supplement tablets

76

Product:-

1) Type of product: Dietary supplement
2) Volume of shrinkage upon contraction: Not known
3) Reaction with oxygen in the headspace: Possible
4) Permeation of product/components through the bottle
wall: None
Bottle:-
1) Material: High density polyethylene
2) Dimensions: diameter - 3.75 inches
height - 5.37 inches
3) Thickness of the body wall: 0.03 inch
4) Type of closure: 45 millimeter continuous thread with
0.0293 inch heat seal liner (paper/
alumdnum.foil/polyethylene)
5) Type of sealing at the finish: Liner sealing
6) Overflow volume: About 400 milliliters
Filling:-
1) Type of filling: Counting
2) Temperature during filling: 72°F
3) Foaming of product during filling: None
4) Headspace volume: N/A
5) Method of capping: N/A

77

6) Time lapse for packing the finished bottles into

the shipper: Packed immediately

Storage and Distribution:-
1) Type of secondary packaging: RSC
2) Type of pallet stacking pattern: Alternate stacking
pattern
3) Storage time of the finished products at the
warehouses: Factory : 1 month
Distribution: 3 months

Customer : N/A

4) Temperature at the warehouses: Factory : 72°F

Distribution: 72-110°F

Customer : 72°F

Paneling:-
1) Location: Mid section of the bottle
2) Shape and the magnitude: Indented
Length: 3 inches
Width : 1.5 inches
3) Percentage of paneling in a lot: 100%
4) Progressive or sudden collapse: Progressive
5) Thickness of the section: 0.029 inch
6) Design of the section: Segment of circle

7) Permanency of the distortion: Permanent

78

8) Time elapsed after filling: 15-20 days
9) Fixed or increased with time: Increased

10) Place first observed: Factory warehouse

79

B I BL I OGRAPHY

80

BIBLIOGRAPHY

Jones D.A., Mullen T.W., (1961), Blow Molding, Ch 10.
Product Testing For Packaging, pp. 135-138, Reinhold
Publishing Corporation, New York.

Rosato Donald V., Rosato Dominick V., (1989), Blow Molding
Handbook, Ch 19. Testing and Quality Control, pp. 771-772,
Hanser Publishers, New York.

Dimitri Tsiourvas et al., (1993), Development of Plastic
Bottles Resistant to Lateral Deformation. Packag. Technol.
Sci., Vol 6, pp. 23-29.

Van Dijk R. et al., (1998), Lateral Deformation of Plastic
Bottles: Experiments, Simulations and Prevention. Packag.
Technol. Sci., Vol 11, pp. 91-117.

U.S. Patent 4.863.046 (1989), Hot Fill Container,
Continental PET Technologies Inc., Norwalk, CT.

U.S. Patent 4.877.141 (1989), Pressure Resistant Bottle
Shaped Container, Yoshino Kogyosho Co.Ltd., Tokyo, Japan.

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