United States
Environmental Protection
Agency
Office of Research and
Development
Washington DC 20460
EPA/600/R-98/045
April 1998
v>EPA
Demonstration of
Packaging Materials
Alternatives to Expanded
Polystyrene
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April 1998
DEMONSTRATION OF PACKAGING
MATERIALS ALTERNATIVES TO
EXPANDED POLYSTYRENE
by
Dean M. Menke
University of Tennessee
Center for Clean Products and Clean Technologies
Knoxville, Tennessee 37996
Cooperative Agreement No CR-821848-01
Project Officer:
Diana R. Bless
Clean Processes and Products Branch
Sustainable Technology Division
National Risk Management Research Laboratory
Cincinnati, OH 45268
NATIONAL RISK MANAGEMENT RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OH 45268
Printed on Recycled Paper
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DISCLAIMER
The information in this document has been funded wholly by the United States
Environmental Protection Agency under Cooperative Agreement CR821848 to the University of
Tennessee's Center for Clean Products and Clean Technologies. It has been subject to peer and
administrative review, and has been approved for publication as an EPA document. Mention of
trade names or commercial products does not constitute endorsement or recommendation for use.
,,n ii, i ,,.,1 -,
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FOREWORD
The U. S. Environmental Protection Agency is charged by Congress with protecting the
Nation's land, air, and water resources. Under a mandate of national environmental laws, the
Agency strives to formulate and implement actions leading to a compatible balance between
human activities arid the ability of natural systems to support and nurture life. To meet this
mandate, EPA's research program is providing data and technical support for solving
environmental problems today and building a science knowledge base necessary to manage our
ecological resources wisely, understand how pollutants affect our health, and prevent or reduce
environmental risks in the future.
The National Risk Management Research Laboratory is the Agency's center for
investigation of technological and management approaches for reducing risks from threats to
human health and the environment. The focus of the Laboratory's research program is on
methods for the prevention and control of pollution to air, land, water and subsurface resources;
protection of water quality in public water systems; remediation of contaminated sites and ground
water; and prevention and control of indoor air pollution. The goal of this research effort is to
catalyze development and implementation of innovative, cost-effective environmental
technologies; develop scientific and engineering information needed by EPA to support regulatory
and policy decisions; and provide technical support and information transfer to ensure effective
implementation of environmental regulations and strategies.
This publication has been produced as part of the Laboratory's strategic long-term
research plan. It is published and made available the EPA's Office of Research and Development
to assist the user community and to link researchers with their clients.
E Timothy Oppelt, Director
National Risk Management Research Laboratory
in
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ABSTRACT
Widespread use of toxic chemicals in all segments of industry and commerce has created
the need to deal with burgeoning waste streams containing toxic chemicals emitted into the air
and water and buried in the soil. Two decades of pollution control regulations have not been
completely effective in reducing environmental releases of toxic chemicals, nor in mitigating the
human health effects from toxic chemical use. The United States Environmental Protection
Agency's 33/50 Program is one example of a new generation program that focus directly on
pollution prevention to reduce toxic chemical releases. The 33/50 Program encourages industry
to enter voluntary agreements to reduce emissions of 17 toxic chemicals.
This report represents the second demonstration of cleaner technologies to support the
goals of the 33/50 Program under the EPA Cooperative Agreement No. CR821848. The report
presents assessment results of alternative packaging materials which could potentially replace
expanded polystyrene in consumer product packaging applications. By replacing EPS with
alternative packaging materials, the use and potential emissions of 33/50 chemicals, could be
reduced. The assessment evaluated the technical (i.e., performance), environmental, and
economic characteristics of EPS and three alternative packaging materials: starch-based foam
plank, layered corrugated pads, and recycled polyethylene foam.
The results of the technical evaluation reveal the strengths and weaknesses of each
protective packaging material. Under standard temperature and humidity conditions, dynamic
drop test results reveal that layered corrugated pads offer as much single-impact protection as
EPS at a material thickness of 1.5 inches. For samples of identical thickness, starch-based foam
and recycled polyethylene foam display a greater ability to absorb energy resulting from multiple
impacts, when compared to EPS. Finally, prototype designs using layered corrugated pads and
starch-based foam protect a tested consumer electronic product to a level comparable to that of
EPS.
To capture the full impact of package manufacturing, and the release of 33/50 chemicals, a
life-cycle perspective was employed to evaluate the environmental impacts of each material. The
release of 33/50 chemicals predominate the pre-manufacturing life-cycle stage. Benzene
emissions to air and water dominate this life-cycle stage for EPS; for starch-based foam planks,
the use of agricultural chemicals for the production of corn results in the use and potential release
of cyanide and other 33/50 chemical; few, if any, 33/50 chemical releases are expected from pre-
manufacturing for layered corrugated pads when manufactured from 100 percent recycled
materials. Within the package manufacturing life-cycle stage, VOC emissions dominate the EPS
process, while energy consumption dominates starch-based foam plank. Finally, each material had
waste management options, each of which represent options to minimize landfill disposal.
Preferred waste management options are presented for each material.
To complete the evaluation of alternative packaging materials, an economic evaluation
was performed on the prototype packaging designs developed for the tested consumer electronic
product. Within this identical packaging application, assuming all other parameters are
equivalent, layered corrugated pads were the most cost competitive packaging alternative when
compared to EPS. Though 37 percent more expensive than EPS, layered corrugated pads were
more cost competitive than starch-based foam. Similar cost comparisons were not available for
recycled PE foam.
IV
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TABLE OF CONTENTS
page
Chapter 1: Introduction . . 1
33/50 Program .;.:.. .;.... .1
Objectives of This Research ..:...... 2
Technical Data ........ ..:;. -; '...-.' .....! 5
Environmental Data 5
Economic Data .. 5
Chapter 2: Packaging Industry . 7
History of Packaging . 7
Market for Packaging and Packaging Materials .. ^ ......... .8
Regulations Effecting the Packaging Industry .....;............. 9
Chapters: Packaging Design and Cushioning Materials . . . ... ...'.-.'. . . .... .'.....- 10
Packaging Design .... ......... . ..../......,..... .............. 10
Cushioning Design Considerations ...;..................:.... .11
Fragility . ... .....;.. . . . . . 12
Distribution Environment ..............:....,....... 12
Impact Shock .......................: 12
Cushioning Configuration 13
Cushioning Materials ..... .". . . . 13
Expanded Polystyrene ............:............ ^.... ; ... 13
Starch-Based Foam Planks 14
Layered Corrugated Pads 14
Recycled Polyethylene Foam 14
Chapter 4: Technical Evaluation 16
Dynamic Drop Tests .......:...................... 16
Apparatus 19
Procedure 20
Dynamic Drop Test Results 21
Stress-Strain Tests 30
Apparatus ..-.." 31
Procedure . . 32
Static Stress-Strain Results . 32
Creep Tests 34
Apparatus .....' 35
Procedure .35
Creep Test Results 36
Prototype Demonstration 36
Cushioning Design .36
Prototype Demonstration Results ',- 39
Conclusions 45
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Chapter 5: Environmental Evaluation .....'..-.... 46
Product Life-Cycle , 46
Pre-Manufacturing Life-Cycle Stages : 47
Expanded Polystyrene 47
Starch-Based Foam Plailk 49
Layered Corrugated Pads : 52
Recycled PEFoam . . . 53
Package Manufacturing Life-Cycle Stages 54
EPS Package Manufacturing - 54
Starch-Based Foam Package Manufacturing 55
Layered Corrugated Package Manufacturing 57
Waste Management Life-Cycle Stages 58
Expanded Polystyrene Waste Management Options 59
Starch-Based Foam Waste Management Options ; 60
Layered Corrugated Waste Management Options 60
Recycled PE Foam Waste Management Options 61
Conclusions ...: 62
Chapter 6: Economic Evaluation 65
Materials and Manufacturing 65
Comparison of Costs - Philips' VCR 65
Comparison of Costs - MAYTAG's Glass Panel . : 66
Additional Cost Parameters 67
Capital Equipment Costs -67
Packaging Line Productivity ..;.., 67
Distribution 68
Consumer Values 69
Conclusions 7ฎ
Chapter 7: Conclusions 71
Technical Evaluation 71
Environmental Evaluation 72
Economic Evaluation 74
Recommendations ' *
References 76
Appendices
Appendix A: Triaxial Piezoresistive Accelerometer : Al
Appendix B: Step-by-Step Procedures for Laboratory Tests Bl
Appendix C: Example of Questionnaire to Assess Facility-Specific Environmental Loading .. Cl
VI
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LIST OF TABLES
page
Table 1: Priority Uses of the 33/50 Chemicals .. ... ,..'. . . . . 3
Table 2: Consumption Patterns for Various Packaging Materials ..... 8
Table 3: Summary of Optimal Static Loads amlCorresponding G-Forces for
Each Material ." . . . . '. . '. . ..'.'.............. 1 ........ 27
Table 4: Decay of Cushioning Properties Following Repeated Shock Impacts at
Optimal Static Load Conditions .,,..',".."."/;...' .,'.'.'..'......'. . . . . 28
Table 5: Comparison of Optimal Gs Under Extreme Conditions ..... , . ...,,', . , 29
table 6: Quantitative Performance Assessment of EPS End Caps . . . . . .'..'..' 40
fable 7: Quantitative Performance Assessment qf Ecoplank Prototype Design 42
Table 8: Quantitative Performance Assessment of First Layered Corrugated
Prototype Design ....''._. ._.^.;:'^.\.....'.'.;.',.",'.,.'....;.... 43
Table 9: Inventory of Inputs and Outputs for EPS Cushion Manufacturing 55
Table 10: Inventory of Inputs and Outputs for Starch-Based Foam Plank
Manufacturing 55
Table 11: Inventory of Inputs and Outputs for Corrugated Pad Manufacturing . ........ 57
Table 12: Possible Waste Management Options :...... 59
Table 13: Features, Obstacles, and Promotion Options for Returnable/Recyclable
Packaging Systems ..'...'....'.'... ... . . . . . . . . 62
Table 14: Summary of Environmental Evaluation, Life-Cycle Perspective 63
Table 15: Comparison of Material Costs '..,...,...''. .,.", . /. . . . . ... 70
Table 16: Summary of Optimal Static Loads and Corresponding G-Forces for
EachMaterial . '.....' 72
Table 17: Summary of Prototype Design Results ... .". . . . 72
Table 18: Summary of Environmental Loadings 73
Table 19: Comparison of Material Costs .74
Vll
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LIST OF FIGURES
page
Figure 1: Chemical Use Tree for Benzene 4
Figure 2: Breakdown of Packaging Waste in Municipal Solid Waste 8
Figure 3: Nine Steps in Packaging Development Pathway 10
Figure 4: Basic Package-Product System 11
Figure 5: Dynamic Cushioning Curves 17
Figure 6: Results of a Single Drop Test (Dynamic Shock) 17
Figures 7A, 7B, and 7C:
Interpretation of Single Dynamic Drop Test Curves 18
Figure 8: Three Regions of a Dynamic Cushioning Curve 19
Figure 9: Schematic Diagram of Dynamic Drop Test Apparatus 20
Figure 10: Typical Response of EPS to Single-Event Impact Shock 23
Figure 11: Typical Response of Recycled PE Foam to Single-Event Impact Shock 24
Figure 12: Typical Response of Starch-Based Foam Planks to Single-Event Impact
Shock 24
Figure 13: Typical Response of Layered Corrugated Pads to Single-Event Shock 25
Figure 14: Dynamic Cushioning Curve for EPS 25
Figure 15: Comparison of Dynamic Cushioning Curves for Recycled PE Foam and
EPS 26
Figure 16: Comparison of Dynamic Cushioning Curves for Starch-Based Foam and
EPS 26
Figure 17: Comparison of Dynamic Cushioning Curves for Layered Corrugated Pads and
EPS 27
Figure 18: Possible Static Stress-Strain Curves 31
Figure 19: Schematic Diagram of Stress-Strain Test Apparatus 31
Figure 20: Comparison of Static Stress-Strain Curves 33
Figure 21: Schematic Diagram of Creep Test Apparatus 35
Figure 22: Theoretical Design of Cushioning Pads - A Four Step Process 37
Figure 23: ISTA Test Procedures for Package-Product Systems Weighing Under
100 Pounds 38
Figure 24: Schematic of Second Ecoplank Prototype Design for VCR 41
Figure 25: Schematic of Layered Corrugated Prototype Design for VCR 42
Figure 26: Schematic of Final Ecoplank Prototype for Maytag's Glass Panel 44
Figure 27: Pre-Manufacturing Life-Cycle Stage for EPS 48
Figure 28: Pre-Manufacturing Life-Cycle Stage for Starch-Based Foam Planks 50
Figure 29: Chemical Flow Diagram for the Production of Atrazine, A Corn Herbicide .... 51
Figure 30: Pre-Manufacturing Life-Cycle Stage for Layered Corrugated Pads 52
Figure 31: Pre-Manufacturng Life-Cycle Stage for Recycled PE Foam 53
Vlll
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CONVERSION TABLE
Units:
British Thermal Units (BTU)
feet (ft)
cubic feet (ft3)
inches (in)
pounds (Ib)
pound per square inch (lb/in2)
square feet (ft2)
square inches (in2)
Multiply by:
1.054
2.93 x ID"4
0.3048
0.028
0.0254
0.4536
703.1
6.895
0.0929
6.45X10-4
To get:
kilo- Joules (kJ)
kiloWatt-hours (kW-hr)
meters (m)
cubic meters (m3)
meters (m)
kilograms (kg)
kilograms per square meter (kg/m2)
kilo-Pascals (kPa)
square meters (m2)
square meters (m2)
ฐC = 0.56 xฐF- 17.78
IX
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ACKNOWLEDGMENT
The Center for Clean Products and Clean Technologies acknowledges the time and
resources offered by the following organizations and individuals.
Philips Consumer Electronics: Without their laboratory resources and professional
expertise, the goals and objectives of the study would not have been achieved. Special
thanks goes to Robert S. Gepp, Staff Engineer, who developed the dynamic drop test
apparatus used in the study and offered his technical guidance throughput the project.
The various package manufacturers: They supplied .material samples and developed
prototype designs, all of which were tested within this project. Special recognition goes
to Tuscarora (Greenville, TN), Menasha Sus-Rap Corporation (Danville, VA), and
American Excelsior (Memphis, TN and Arlington, TX).
Dr. Raymond Krieg, University of Tennessee Mechanical Engineering Department, and his
mechanical engineering students who performed static, stress-strain, and creep tests on
selected packaging materials.
Dr. John R. Mount, Food Science and Technical University, and the University of
Tennessee Food Science Lab which supplied the apparatus used to perform the static,
stress-strain tests of the study.
Without their cooperation and support, the results of this study would not have been possible.
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CHAPTER!
INTRODUCTION
The hazardous waste problem and many of the persistent air and water pollution problems
are primarily toxic chemical problems. Widespread use of toxic chemicals in all segments of
industry and commerce has created the need to deal with burgeoning waste streams containing
toxic chemicals emitted into the air and water and buried in the soil. Two decades of pollution
control regulations have not been completely effective in reducing environmental releases of
toxic chemicals. Nor have regulations always protected workers from the effects of toxic
chemicals used in the workplace or consumers from the effects of toxic chemicals found in
consumer products. However, a hew generation of programs and policies have emerged which
have a greater potential to reduce toxic chemical releases. The United States Environmental
Protection Agency's (EPA) 33/50 Program is one such new-generation program.
33/50 PROGRAM
The 33/50 Program was a voluntary pollution prevention initiative to reduce national
releases and off-site transfers to the environment of 17 toxic chemicals. The Program asked
industry to voluntarily develop their own reduction goals that contribute toward national
reduction goals of 33 percent by the end of 1992 and 50 percent by the end of 1995: Reductions
were measured against a 1989 baseline of information reported to EPA under the Toxic Release
Inventory (TRI). The 17 chemicals or chemical groups included in the 33/50 Program are as
follows: '
Benzene
Cadmium and Cadmium Compounds
Carbon Tetrachloride (CTC)
Chloroform (CFM)
Chromium and Chromium Compounds
Cyanide and Cyanide Compounds
Lead and Lead Compounds
Mercury and Mercury Compounds
Methylene Chloride (DCM)
Methyl Ethyl Ketone (MEK) ,
Methyl Isobutyl Ketone (MIBK)
Nickel and Nickel Compounds
Tetrachloroethylene (PCE)
1,1,1-Trichloroethane (TCA)
Toluene
Trichloroethylene (TCE)
Xylene
EPA selected these compounds for the voluntary pollution prevention initiative based on
a number of factors including their high production volumes, high releases and off-site transfers
relative to their production, opportunities for pollution prevention, and their potential for causing
human health and environmental effects.fl]
EPA's National Risk Management Research Laboratory (hereafter NRMRL, formerly
Risk Reduction Engineering Laboratory) has funded research in support of the 33/50 Program.
The goal of the NRMRL-funded research is to evaluate the performance and cost of pollution
prevention options and to disseminate that information through reports, technical meetings,
seminars, and other media. While this research was originally funded by NRMRL to support the
33/50 Program, the technologies that will be evaluated have a broad range of applications within
1
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industry. This should offer pollution prevention benefits beyond the reduction of national
pollution releases and off-site transfers of the 33/50 chemicals.
OBJECTIVES OF THIS RESEARCH
The "Cleaner Technology Demonstrations for the 33/50 Chemicals" project is a
cooperative agreement between the EPA-NRMRL and the Center for Clean Products and Clean
Technologies (hereafter Center) funded by NRMRL in support of the 33/50 Program. The
overall objective of this project is to demonstrate substitutes for the 33/50 chemicals in order to
encourage reductions in their use and release. For the substitutes that will be evaluated, this
study has objectives in the areas of technical, environmental, economic, and national impact
evaluations. The following are the specific objectives in each area:
1. Technical evaluation
evaluate the effect of the substitute(s) on process and product performance as
compared to the 33/50 chemical(s)
2. Environmental evaluation
evaluate the potential for reduction in releases and off-site transfers of the 33/50
chemical(s) in the production process or product stage in which the 33/50
chemicals are used and released
compare the overall life-cycle environmental attributes of the 33/50 chemicals and
the substirute(s) for the same use
3. Economic evaluation
evaluate the total cost of the substitute(s) as compared to the 33/50 chemical(s)
4. National environmental impact evaluation
evaluate the environmental impact of replacing the 33/50 chemical(s) with the
substitute(s) on a national scale
The subjects of the demonstration projects were selected from seven priority use clusters
of the 33/50 chemicals identified in The Product Side of Pollution Prevention: Evaluating the
Potential for Safe Substitutes.,[2] The seven priority use clusters are shown in Table 1. Primary
use clusters are defined as those products and/or processes that consume a significant portion
(weight fraction) of the 33/50 chemicals. The Product Side of Pollution Prevention: Evaluating
the Potential for Safe Substitutes used chemical use trees as the analytical tool to evaluate the
priority use clusters of the 33/50 chemicals. Examples of chemical use trees can be found
throughout that document.
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TABLE 1 - PRIORITY USES OF THE 33/50 CHEMICALS
Priority Use Cluster
batteries
metal finishing
plastics and resins
paints and coatings
degreasing
dry cleaning
paint stripping
33/50 Chemicals
Cd, Hg; Ni, Pb
Hg
Cd, Cr,Ni
cyanide compounds ,
benzene, toluene, xylene
Cd,Cr ;'...-.
toluene, xylene, MEK, MIBK
Cd,Cr,Pb ...
benzene, toluene, cyanides
TCA, TCE, PCE (CFCs), DCM
PCE, TCA
DCM
Function
electrodes
additive
metal plates
plating path chemicals
chemical intermediates
stabilizers
solvents
pigments
intermediates of paint resins
solvents- '
solvents
solvents
Source: U.S. Environmental Protection Agency. The Product Side of Pollution Prevention: Evaluating the
Potential for Safe Substitutes. September 1994. EPA/600/R-94/178. '
Key: Cd - cadmium
CFCs - chlorofluorocarbons
Cr - chromium
DCM - methylene chloride
Hg - mercury
MEK - methyl ethyl ketone
MIBK - methyl isobutyl ketone.
Ni - nickel
Pb - lead
PCE - tetrachloroethylene
TCA- 1,1,1-trichloroethane
TCE - trichloroethylene
This report represents the second demonstration project to be completed under the EPA-
NRMRL project. The first demonstration project focused on substitutes for solvent degreasing
processes that eliminate the use of chlorinated organic chemicals; results of this research are
presented in Demonstration of Alternative Cleaning Systems.[3] This second demonstration
project evaluates alternatives to expanded polystyrene (hereafter EPS) as a cushioning material in
consumer and industrial packaging. EPS is an example of the priority use cluster "plastics and
resins," and is produced from raw materials derived solely from the 33/50 chemical benzene, as
the chemical use tree presents in Figure 1. '-.--
' Three 'alternative? cushioning materials were identified for evaluation within this research:
starch-based foam planks, layered corrugated pads, and recycled polyethylene foam. Some of
these materials have been used as cushioning materials for some time (corrugated and
polyproethylene); others are just now entering the market and identifying/establishing viable
applications. These materials are termed 'alternative' because each offers unique features beyond
their cushioning capabilities. These unique features include their manufacture from recycled
materials, biodegradability, water solubility, recyclability, and reusability. These features as well
as the use of 33/50 chemicals are assessed and presented within the context of the evaluations in
this project.,
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The goal of this research was to present information on the environmental, economical,
and performance characteristics of alternative packaging materials. This information could be
used by industry, manufacturers, researchers, and consumers to advance the .application of
alternative cushioning materials. To accomplish this goal, technical, environmental, and
economic evaluations were completed to assess various characteristics and parameters
concerning the production, use, and disposal of the cushioning materials. The properties and
cushioning characteristics of EPS represent the baseline for this research; evaluation results for
each material are compared against those of EPS. A variety of data was required to perform
these evaluations, a brief description of which is presented below.
Technical Data
Technical data, specifically the cushioning performance/capabilities of each material,
were generated by four separate laboratory test series. Three test series evaluate the general
cushioning characteristics of each material using square test samples. These test series included
dynamic drop tests, static stress-strain tests, and creep tests. The fourth laboratory test applied
selected cushioning materials to a consumer or industry product packaging application. Products
were provided by industry partners and packaged in prototype designs developed by the vendors
of the selected alternative cushioning materials. These prototype package-product systems were
then subjected to a series of performance tests based on industry partner specifications or
established International Safe Transit Association test procedures. A discussion of the laboratory
procedures and the test results are presented in Chapter 4.
Environmental Data
The environmental evaluation applies a life-cycle perspective to the production, use, and
disposal of each of the cushioning materials. With this perspective, quantitative and qualitative
data was used to assess and compare the environmental burdens of each packaging material. The
data required to complete this evaluation were obtained from a variety of sources. From each
material supplier, primary data were collected through questionnaires and site visits for the
cushioning material's manufacturing processes. The questionnaires were distributed by mail and
completed by the contacts established in each manufacturing facility. Site visits arranged with
each contact allowed Center staff to become familiar with the manufacturing processes and ask
specific questions to complete and clarify questionnaire responses. Additional data to establish
the remaining life-cycles stages of each material were gathered from publicly available data.
Examples of such data include the TRI database, published life-cycle assessments, and
government surveys. Results from this evaluation are presented in Chapter 5, Environmental
Evaluation.
Economic Data
Finally, a quantitative and qualitative economic assessment of each material was
performed to fulfill the goals of the economic evaluation. Utilizing the prototype demonstration
results, a quantitative evaluation of the equivalent use of each alternative material, as compared
to the current EPS application, was determined. Based on this information and the production
rate of each industry partner, estimates of packaging production and supply costs were given by
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each material supplier. Economic considerations that were evaluated on a more qualitative basis
include the possible rates of production and the ability to incorporate the alternative material into
an existing packaging production line. The details of this evaluation are presented in Chapter 6.
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:;. .- ''';>.-: .--: -. - . ./ ;.-...- - CHAPTER2 -. . -...
..". ; -, '. ', -'-.is. v PACKAGING INDUSTRY - -.:.
Packaging is viewed by many consumers merely as a means of containing a product. The
function of a package, however, is much more extensive. "It is art and science; it is materials and
equipment; it is protection, promotion, law, logistics, manufacturing, and materials handling all
rolled into one."[4] Packaging has many faces. In its familiar forms it is the box on the shelf at
the grocery store and the wrapper on the candy bar. It can also be the crate around a piece of
industrial machinery or a bulk container for chemicals (e.g., 250 gallon tote). A package is a
process of getting products from the source of production to the point of use in the most
beneficial and cost effective manner. To support our current system of production and
distribution, packaging, with its many functions, is essential.
HISTORY OF PACKAGING
By the end of the 1,9th century the Industrial Revolution had created a high level of
productivity and inexpensive means of mass transportation for moving products long distances to
the customer. Customers were able to pick and choose from a variety of competing products. In
this buyer's market, the customer began to demand more for the money, including better product
protection (i.e., undamaged, unadulterated, uncontaminated products). With greater affluence,
consumers began accepting packaging as a convenience to be discarded without thought.
Initially viewed as a necessary evil, packaging became a means by which a manufactured product
could be marketed and sold. [5]
Unit packaging was the result of the demands for protection and convenience. By the late
1970's, however, the characteristics of unit packaging which offered the benefits of protection
and convenience became an environmental issue as landfill space became limited and resource
depletion became an international issue. In 1986, packaging waste accounted for approximately
34 percent (by volume) of the U.S. municipal solid waste stream.[6] This packaging waste was
composed of paper (approximately 50 percent by weight), glass (26 percent), plastic (14 percent),
steel (7 percent), and aluminum (3 percent); this distribution is presented in Figure 2.[7] The
demand for protection and convenience was joined by the demand for more environmentally
benign packaging materials and packaging designs. Recycled content, recyclability, and
reusability are of interest to the consumer.
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FIGURE 2 - BREAKDOWN OF PACKAGING WASTE IN MUNICIPAL SOLID WASTE
(by weight)
alumminum 3%
steel 7%
paper 50%
plastic 14%
glass 26%
MARKET FOR PACKAGING AND PACKAGING MATERIALS
The market for packaging in the United States totals approximately $100 billion annually
(up from $25 billion hi 1974)[8], representing only 1.4 percent of the $7 trillion United States
economy.[9] This expenditure calculates to an average of $400 per year per person (i.e., man,
woman, and child) in this country. Worldwide, packaging expenditures total approximately $350
billion, or $70 per person per year. [10] The significance of these figures is subject to
interpretation. Some argue that the consumption patterns of the United States are excessive;
others argue that our economy, and even the advancement of civilization, cannot develop without
packaging.[ll]
Over the years, the relative market share for different types of packaging materials has
shifted. Plastics sales have continued to grow since the 1950's, while the market share held by
paper and paperboard has fluctuated. These figures are reflected in Table 2 which presents
consumption rates by material within the packaging market.
TABLE 2 - CONSUMPTION PATTERNS FOR VARIOUS PACKAGING MATERIALS
(million Ib)
Plastics in Packaging1
Expanded Polystyrene2
Low Density Polyethylene2
Paper and Paperboard1
Starch-Based Loose-Fill3
1991
16,568
4,560
0
1993
19,569
4,508
4
1995
NA
730
7,252
NA
8
Sources:
1 United Nations Secretariat. 1993 Industrial Commodity Statistics Yearbook: Production and Consumption
Statistics. 1996.
2 Modern Plastics. January 1992, 1994, 1996.
3 Starch-based loose-fill packaging material was introduced in 1990. Consumption figures were estimated as a
percentage of loose-fill polystyrene. Starch-based foam plank was introduced in 1996.
NA: Not available.
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REGULATIONS EFFECTING THE PACKAGING INDUSTRY
In recent years, packaging legislation has been introduced and enacted at all levels of
government: state, federal, and international. At the state level, 2,000 solid waste bills were
introduced, with 300 of them specifically addressing packaging issues.[12] The types of
legislative initiatives which address the environmental impacts of packaging include resource
reduction measures, measures encouraging or mandating recyclability of products, deposit fees,
and variable garbage collection fees. Though not legislative in nature, an example of a regional
initiative is that of the Council of North Eastern Governors Resource Reduction Task Force. The
Task Force has recommended, among other actions, the adoption of preferred packaging
guidelines.
At the federal and international level, the German Ordinance for the Avoidance of
Packaging Waste (1991) is an example of an ambitious and far-reaching legislative initiative. In
short, this Ordinance requires manufacturers to reuse packaging or bear the costs of having it
recycled (i.e., if the manufacturer made it, the manufacturer is responsible for it throughout its
life cycle).[13] Similar legislation has been implemented in The Netherlands, France, the United
Kingdom, Australia, and the European Union.
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CHAPTERS ' -
PACKAGING DESIGN AND CUSHIONING MATERIALS
A package designer must develop effective and economical package-product systems. ,
Effective packaging offers the protection, convenience, and possibly environmental attributes
expected by the consumer. Among other factors, the economics pf packaging may be affected by
material costs, as determined by the product and material markets and demands for the product
manufactured, as well as the packaging material bulk and weight which affect the costs of
transport. With a knowledge of the physical world (i.e., physical properties of the product and
packaging) the designer is able to develop a functional and effective package-product system.
The implementation of this package-product system, however, is determined by cost and other
considerations within the economic world. Therefore, the designer is constrained by both the
physical world and the economic world, and a balance must be established between them. [14]
"The ultimate design of a package is a choice which represents the distillation of a multitude of
lesser decisions, each relating to a specific package or product requirement as defined by
management, marketing, sales, manufacturing, or research and development. Each of these
groups approaches the subject from a different viewpoint, yet makes an important contribution to
thewhole."[15]
PACKAGING DESIGN
Nine steps have been identified and defined for the packaging development pathway. [16]
These nine steps, identified in Figure 3, combine and balance the physical and economic worlds
mentioned above. The technical evaluation of this research incorporates aspects of Steps 1, 2, 3,
5, and 8; Steps 3 and 4 are considered by the environmental evaluation; and the economic
evaluation addresses Steps 4, 5, 6, 7, and 8.
FIGURE 3 - NINE STEPS IN PACKAGING DEVELOPMENT PATHWAY
Step #1 definition of product properties as they relate to, the package technical requirements
2 definition of package technical and functional properties
3 definition of package styling and design requirements
4 identification of legal or other restrictions/requirements
5 selection of possible package designs and materials
6 estimation of probable cost of 'development
7 decision whether to proceed
8 package preparation and testing for performance .
9 decision whether to proceed for market test
Source: Griffin, Roger C. and Stanley Scharow. Principals of Package Development. The AVI Publication
Company, Inc., Westport, CT. 1972.
10
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CUSHIONING DESIGN CONSIDERATIONS
Cushioning systems (the material and its designed configuration) are incorporated in
package-product systems to protect fragile items. Figure 4 illustrates a basic package-product
system which incorporates a cushioning system. The product, which is to be protected from
damage, is denoted 'P' in the figure. The container system, comprised on a rigid outer container
(denoted 'B') and cushioning material (denoted 'C'), encase the product.
FIGURE 4 - BASIC PACKAGE-PRODUCT SYSTEM
p
Tc
B
Key: P , = product
B = rigid outer container
C = cushioning material
Tc = thickness of cushioning material
When a-package-product system, such as that shown in Figure 4, is dropped on a non-
resilient, rigid surface, the outer container can impact the surface with considerable force. The
cushioning material acts as a buffer between this force and the fragile product; the product does
not stop as abruptly as the outer container and the force experienced by the product is reduced.
Since any outer container can be devised to encase the cushioning system and product, the crucial
factors which must be considered hi a cushioning system design are the cushioning material, its
thickness (denoted Tc in the figure), and its configuration. [17]
From this description of cushioning design, the nine steps for packaging design can be
conveniently reduced to four basic considerations when testing and designing cushioning
materials and systems. These four basic considerations are as follows[18]:
Fragility level.
Distribution environment (e.g., drop height, temperature, and time).
Impact shock.
Cushioning configuration.
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Fragility
In order to decide what protective properties a package must have, it is first necessary to
know the properties of the product it is to contain. Manufacturers typically know the integrity of
their product(s), and therefore have some measure of its fragility level. Fragility is expressed as
the maximum G-forces a product or component can experience without resultant damage. G-
force is expressed as a dimensionless ratio of the maximum acceleration that an item can safely
withstand to the acceleration due to gravity. If susceptible components of a product are
inseparable from the rest of the product, the package-product system (i.e., cushioning system)
must be designed to protect the most fragile component; for example, a consumer electronic such
as a VCR or television, or a glass object such as a vase or bottle. For the subject of this research
project, the focus was a consumer electronic product (i.e., VCR) with some fragility level that
must be protected. In a VCR, the plastic case may be able to withstand a greater impact force,
greater than an unsupported internal electronic piece such as a circuit board. How a package
designer uses this measure of fragility is discussed in the prototype demonstration section of
Chapter 4, Technical Evaluation.
Distribution Environment
The distribution environment within which a package-product system must travel can
significantly influence the design of a cushioning system. The drop height, for example, is
defined as the free fall distance a package-product system may drop resulting in an impact
velocity and calculated impact force. The drop height is dictated, in part, by the package-product
system itself. A light weight object can be thrown like a baseball; thus, the potential drop height
to which the package-product system could be subjected may be significant. As the package-
product system increases in weight, the drop height decreases. Various standard methods
prescribe worst-case potential drop height based on the weight of the package-product system.
The highest drop height is typically 30 inches for light weight objects, while for heavy objects
(over 250 Ib) the potential drop height is reduced to 9 inches. [19] Temperature, humidity, and
storage time are other distribution considerations that must be defined and addressed when a
cushioning system is designed. The technical evaluation of Chapter 4 evaluates a finite array of
distribution environments and their effect on cushioning materials.
Impact Shock
The dynamic laboratory test series completed within the context of the technical
evaluation addresses the issue of impact shock. Shock can be described as a disturbance
produced by a suddenly applied force in the form of a complex pulse. To evaluate a cushioning
material's response to varying shock pulses, a series of static loads are dropped onto material
samples from a standard drop height. Expressed as either a single-event impact shock pulse as a
function of tune, or as a dynamic cushioning curve, the results of drop tests offer a concise and
consistent representation of cushioning material properties that aid the packaging designer. The
generation, integration, and use of drop test results and dynamic cushioning curves are explained
further in Chapter 4, Technical Evaluation.
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Cushioning Configuration
Cushioning configuration can be considered the engineered shape of the cushioning
material in a specific package-product application. Configuration addresses the thickness,
contours, fins, etc. which optimize cushioning ability while minimizing the thickness and quantity
of material used (therefore optimizing cost). A cushioning system can be designed as corner pads,
end caps, engineered or convoluted pads, etc. The material suppliers of selected cushioning
materials incorporate configuration into the design of a prototype packaging system for a specific
consumer/industrial product application. In the prototype cushioning design, the three previously
defined considerations are incorporated. Knowledge of the product's fragility, the drop height
from which it could potentially be dropped, and the cushioning properties of the materials must all
be known to design an effective packaging system. How these considerations are used to design a
cushioning system is explained in more detail under the prototype evaluation of the Technical
Evaluation, Chapter 4. ,
Though included in the nine design steps for packaging, regulations have been left out of
these four considerations for cushioning design. Regulations, as presented above, may place
additional restrictions on the design process and must be considered by the packaging designer.
Environmental regulations are only one set of regulations that may be applied to packaging. In
this study an entire chapter is devoted to economics and the costs and benefits incurred by
applying an alternative packaging material to consumer or industrial product packaging.
Furthermore, environmental issues including regulations are covered in Chapter 5, Environmental
Evaluation.
CUSHIONING MATERIALS
As previously stated, this research evaluated four cushioning materials. EPS was
considered the 'typical' cushioning material used in consumer product applications, and represents
the baseline against which the other materials are compared. The remaining cushioning materials;
starch-based planks, layered corrugated pads, and recycled polyethylene foam, represent
alternative cushioning materials which could replace EPS hi current industrial and commercial
applications. Each material is described in detail below.
Expanded Polystyrene
In 1931 Dow Chemical Company developed and marketed the first extruded polystyrene
foam known as Styrofoamฎ. It is the oldest synthetic and one of the best known cellular plastics.
EPS offers many properties desirable in a packaging material; for example, EPS is light weight,
has a high strength-to-weight ratio, low moisture absorption, little or no odor, low toxicity, and
has good insulating properties. In 1965 EPS was the most widely accepted foamed plastic
material used for cushioning. Today, EPS is one of three foamed plastics (along with
polyethylene and polyurethane) that dominate cushioning applications. .
Philips Consumer Electronics (hereafter Philips) was the primary industry partner in this
demonstration project. Philips utilizes EPS as protective packaging material in most national and
international consumer product packing applications. With a goal of demonstrating an alternative
cushioning material in one of Philip's many applications, the Center adopted many of the
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packaging criteria implemented at Philips for this research. One primary criterion adopted was
the allowable thickness of the cushioning material; all material samples to be evaluated were to
have a thickness of 1.5 inches. This criterion was used to maintain the distribution efficiency
(termed "cubic efficiency") established by Philips for all products. EPS samples of this thickness
were obtained from Tuscarora, Philips' sole supplier of cushioning material in Tennessee.
Starch-Based Foam Planks
In November 1990, American Excelsior began to market its starch-based loose fill
cushioning material as an alternative to polystyrene "peanuts." Viewed by many manufacturers
and consumers as an environmentally superior packaging alternative, EcoFoam has gained an
increasing market share since its introduction. Using this trend, and to expand into additional
markets, American Excelsior began to develop and market "Shapes and Sheets," a starch-based
foam sheet which could be manufactured into cushioning pads. Within the time frame of this
study, the Shapes and Sheets product evolved into the current American Excelsior product
EcoPlank - a standard 2 inch plank composed of layers of corrugated starch-based foamed sheets
bound together with a water-soluble, starch-based adhesive. EcoPlank represents a biodegradable
and water-soluble cushioning product manufactured from a renewable natural resource.
American Excelsior manufactured EcoPlank at a thickness of 1.5 inches for this study.
Layered Corrugated Pads
Layered corrugated pads are not new to the packaging market as a cushioning material.
In the early 1950's corrugated boxes were a primary source of protective (i.e., cushioning)
packaging, and in the 1970's the Forest Products Laboratory, under the direction of the U.S.
Department of Agriculture, systematically tested various layered corrugated pads for their
cushioning properties and possible applications. Due to advances in the plastics industry and the
low cost of plastics, however, the application of layered corrugated pads has been limited.
Menasha Corporation's Sus-Rap Division supplied the Center with flat, 1.5 inch thick
layered corrugated pads composed of 100 percent recycled, 26 pound kraft paper for this study.
The Sus-Rap Division, located in Danville, Virginia, is part of Menasha Corporation's Material
Handling Group. Manufactured from single-faced corrugated sheets bonded together by a water-
soluble starch-based adhesive, these corrugated pads offer a product which is composed of
recycled material and is recyclable in any corrugated recycle program. Menasha manufactures and
markets pads, angles, corners, and troughs to a variety of consumer product manufacturers (e.g.,
furniture manufacturers).
Molded pulp and honeycomb products are examples of paper and paperboard protective
packaging materials, but they were not evaluated in this project due to budget and time
constraints.
Recycled Polyethylene Foam
As mentioned above, polyethylene foam has been one of three dominant polymeric
materials utilized as a cushioning material in packaging applications. For this study, polyethylene
foam was selected to represent a cushioning material that is reusable due to its strength and
resilience. If designed into a reusable/returnable container system, polyethylene foam can offer
14
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significant economic and environmental advantages which will be discussed in this report.
Furthermore, recycled polyethylene foam (hereafter recycled PE foam) is manufactured from
recycled material and is recyclable itself. Typically manufactured as a 2 inch plank, the Center
received recycled polyethylene foam from the Stephen Gould Corporation (a packaging design
consulting firm) in a thickness of 1.5 inches to maintain a consistent evaluation. PE foam is
manufactured throughout the United States from either virgin resin or a combination of virgin and
recycled resin. AVI Foam, in Arlington, Texas was the particular supplier in the Southeast with
which the Center worked during this project.
15
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CHAPTER 4
TECHNICAL EVALUATION
The objective of the technical evaluation was to assess various cushioning properties of
each of the four packaging materials. Three separate tests comprise the technical evaluation of
this research. Two laboratory test series were performed to evaluate the physical properties of
each cushioning material. Dynamic drop tests were used to assess cushioning characteristics;
static compression tests were performed to evaluate relationship between stress and strain
independent of material size or shape; and creep tests were conducted to determine material
deformation under extended periods of stress. The fourth and final test series, prototype
demonstrations, evaluated the use of selected cushioning material in specific product packaging
applications.
Positive characteristics of each cushioning material were revealed by the results of the
technical evaluation. EPS and layered corrugated pads offered the greatest protection from
single-event shock impacts. However, the protection offered by layered corrugated pads
decreases significantly following repeated impacts. Starch-based foam plank and recycled PE
form out-perform EPS in multiple impact tests, showing the least deterioration of cushioning
potential even after five dynamic shock impacts. These and other results are presented below.
Raw data supporting these results are published separately and can be obtained from the U.S.
EPA.
DYNAMIC DROP TESTS
The cushioning capabilities of a packaging material are traditionally presented by
dynamic cushioning curves. [20] A dynamic cushioning curve is a graphic representation of
dynamic shock cushioning offered by a cushioning material over a variety of static load
conditions. Figure 5 presents an example of the dynamic cushioning curves which are used to
market a cushioning material. The vertical axis, G-force, is the dimensionless ratio between an
acceleration hi length-per-time-squared units and the acceleration of gravity in the same units.
The horizontal axis, static load (stress), is the applied mass divided by the area to which the mass
is applied. A different curve is required for each drop height, material thickness, and type of
material. Typically, multiple curves are displayed on the same graph depicting different material
thicknesses at one drop height.
To generate a dynamic cushioning curve, a series of drop tests must be performed. These
tests involve dropping a specified static load, from a specified height (i.e., free fall drop height),
onto a material sample of set dimensions (i.e., surface area and thickness). The acceleration of
the mass is monitored over tune, and the force imposed on the sample materials by the falling
weight, expressed as G-force, is calculated from the acceleration data. A plot of G-force versus
tune, depicted hi Figure 6, is the result of the analysis of a single drop test. The maximum G-
force experienced by the sample materials, circled in Figure 6, represents a single data point for a
specified static load on the dynamic cushioning curve. A series of drop tests which vary the
static load (keeping drop height and material sample dimensions constant) will generate the
needed data to create dynamic cushioning curves for a material of a specified thickness.
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FIGURE 5 - DYNAMIC CUSHIONING CURVES
G-Force
i r i t i v \
Static Load
FIGURE 6 - RESULTS OF A SINGLE DROP TEST (DYNAMIC SHOCK)
maximum G-force
G-Force
Time
Note: A typical acceleration-time curve generated by a dynamic drop test is not as smooth as the curve presented
here. To eliminate the "noise" experienced and introduced by the recording instruments, apparatus, and
packaging system, the curve data is filtered at a level no lower that 10 times the basic pulse frequency.
The curve for a single drop test can offer additional information regarding the general'
properties of the cushioning material. An optimally loaded cushion will have rise tune to and
decay time from the maximum force that are approximately equal in duration. If the cushion is
overloaded, the rise tune becomes substantially greater than the decay time. Most of the static ..
load's impact duration time was spent during deflection (bottoming) of the cushion, resulting in a
high deceleration rate. If the rise time of the pulse is substantially less than the decay time,
generally the cushion is under-loaded. That is, the cushioning material is too stiff and does not
deflect the static load during impact. Figures 7A, 7B, and 7C shows each of the loading
conditions. In each case the vertical axis is G-force, the horizontal axis is time, "R" represents
rise tune, and "D" represents decay time. [21]
17
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05
u
H
1
ft*
O
ฃ
Q
U
O.
-------
Similarly, three regions can be generally identified in a dynamic cushioning curve: the
under-stressed region, the over-stressed region, and the optimal region. These regions are
depicted in Figure 8. The optimal region includes the lowest resultant force for that material and
its tested configuration (e.g., thickness, contours). A packaging designer thus designs a
cushioning system within this region. This design procedure is explained later within this chapter.
FIGURE 8 - THREE REGIONS OF A DYNAMIC CUSHIONING CURVE
G-Force
under
stressed
Static Load
Apparatus
The apparatus used to perform the dynamic drop tests was designed and constructed by
the packaging engineers of Philips. Schematically represented in Figure 9, the primary
components of the apparatus include a static-load platen, pneumatic-suction platen, and a
Endevco Model 7267A Tri-Axial Piesoresistive Accelerometer (i.e., transducer) coupled to a
computerized data acquisition system. Transducer details are presented in Appendix A.
Both platens move'freely up and down three tightly strung steel guide-wires mounted
within the frame of the apparatus. Various static loads can be mounted to the bottom of the
static-load platen with three nut-and-bolt pairs. To the top of this platen is mounted the
transducer with double-sided masking tape. The pneumatic-suction platen can be raised and
lowered by a hand-operated winch. When mounted to a compressed air source, the pneumatic-
suction platen grabs the static-load platen and the system is raised to the desired height via this
winch. Material samples are mounted on a sample platform with double-sided masking tape, and
the platform is slid into position directly Bunder the static-load platen. By closing the compressed
air valve, the static-load platen drops, impacting the material sample. The transducer, in turn,
records the acceleration-time history of the drop test and displays the .shock pulse on the
computer screen.
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FIGURE 9 - SCHEMATIC DIAGRAM OF DYNAMIC DROP TEST APPARATUS
l
2
3
4
5
6
winch
compressed air source
pneumatic-suction platen
static-load platen
sample location on platform
transducer connected to
computer data acquisition
system
Procedure
The procedure followed for the dynamic drop test laboratory experiments was from the
American Society for Testing and Materials (hereafter ASTM) Standard Method D 1598-91,
Standard Test Methods for Dynamic Shock Cushioning Characteristics of Packaging Material. A
detailed, step-by-step description of this procedure can be found in Appendix B. Information
pertinent to the results of the tests series is discussed below.
A series of six static loads were used to generate the dynamic cushioning curves for each
of the materials; starting at 8 Ib, the weight of the static-load platen was increased by 5 Ib
increments to an upper limit of 33 Ib. The static load was dropped onto material samples from a
drop height of 30 inches. Following the ASTM methodology, each material sample was
subjected to a maximum of five consecutive drops at the same static load with an interval of at
least one minute between drops.1 Three sample replicates at each static load increment were
performed for each alternative material; two sample replicates at each static load increment were
performed for EPS samples. Fewer replicates for EPS were required due to its well defined
cushioning characteristics and consistency between samples; similar data were not available for
the alternative materials.
1 At high static loads, some material samples could not absorb five consecutive drops. The series was
discontinued after a G-force which exceeded the transducer setting was experienced.
20
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All acceleration-time histories were recorded for each drop series. The first-drop peak G-
force for each replicate was filtered at 200 MHz (i.e., no lower than 10 times the basic pulse
frequency, following Philips' and other packaging expert procedures) to eliminate 'noise.'
Replicate values were then averaged and recorded for use in the dynarnic cushioning curves
presented below. If the standard deviation of these filtered and averaged data was greater than 10
percent of the average, one additional sample was tested and included in the average calculation
(as specified in the Quality Assurance Project Plan).
Three separate environmental conditions were tested during the dynamic drop test series.
Samples stored in an office environment (average temperature was 22 ฐC; average relative
humidity was 51 percent) represented 'standard' conditions. Samples were also tested under
desert and tropical environmental conditions. Temperature and humidity for these samples were
based on ASTM methodology D 4332-89, Standard Practice for Conditioning Containers,
Packages, or Packaging Components for Testing. These conditions are as follows:
Desert conditions: 60 ฐC and 15 percent relative humidity
extremely high heat and low humidity
Tropical conditions: 40 ฐC and 85 percent relative humidity2
high heat and extremely high humidity
Using a temperature controlled chamber at Philips, material samples were conditioned under these
environments for at least 72 hours before test runs. Dynamic drop tests were performed on these
conditioned samples by taking one sample from the chamber at a time, leaving the remaining
samples under the extreme conditions. ;
Dynamic Drop Test Results
Standard Conditions. Following the procedures presented above and in Appendix B, dynamic
cushioning curves were generated for six different materials: EPS; low- and high-density layered ,
corrugated pads; low- and high-density starch-based planks; and recycled PEfoam. Based on
material sample size (6 x 6 inch square), the weights of the static-load platen resulted in a range of
static loads from 0.23 Ib/sq inch to 0.93 Ib/sq inch for recycled PE foam, starch-based planks, and
corrugated pads. The EPS samples, which were 4x4 inch square, experienced a static load range
of 0.50 Ib/sq inch to 2.12 Ib/sq inch.
Figures 10, 11, 12, and 13 show typical single-event impact shock response curves for
each material at optimal static load conditions. Each of these curves have been 'filtered at 20Q,
MHz. From the theoretical discussion above, a number of observations can be made from these
curves.
1. Both representative curves of EPS and recycled PE foam reveal a shape characteristic of
an optimally loaded sample discussed in Figure 7A. The rise time to and decay time from
the peak G-force are nearly identical. Each single-event shock impact response curve for
these materials revealed such a shape. The response curve for recycled PE foam,
The environmental conditioning chamber utilized for the extreme conditions was not properly operating
during the tropical test conditions. Though it was set for a relative humidity of 85 percent, monitoring revealed an
average relative humidity of 91 percent
21
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however, is more symmetrical. The rise and decay times for recycled PE foam (Figure
11) are within 4 percent of each other, while for EPS the rise time is more than 14 percent
greater than the decay-time (Figure 10).
2. The curve for the starch-based planks, Figure 12, shows the greatest symmetry and may
represent the most optimally loaded sample. However, the peak G-force recorded for this
drop is high (in comparison to the other curves), and the rise time and decay time slopes
are quite steep. A wider, more sloping bell-shaped curve is considered more optimal;
energy is dissipated over a greater time period with less maximum force experienced.
3. Finally, Figure 13 shows the characteristic shock impact response curve for the layered
corrugated pads. Resembling that of an under-loaded material, all first-drop impact
response curves for the corrugated samples displayed a shape such as this. One possible
interpretation of this shape is that the individual layers of fluted material resist collapse
up to a certain force (steep rise time slope), then subside layer by layer under a critical
force until the impact has been absorbed (the jagged, flat top). The rise time slope is very
steep until sufficient force is reached to cause the initial layer of fluted material to give
way. A cascade effect of subsiding layers results until the energy of the static load is
absorbed and the decay tune slope occurs.
Figures 14,15,16, and 17 represent dynamic cushioning curves for each of the four
cushioning material types. For the purpose of comparison, each of the alternative material
cushioning curves is plotted against that of EPS. Further interpretation of each dynamic
cushioning curve follows each plot. For supporting data and calculations, the reader should
request the separate supplemental report from the U.S. EPA. Table 3, which follows the
discussion of each cushioning curve, summarizes the optimal static load and corresponding G-
force for each material. ;
As seen by the dynamic cushioning curve of Figure 14, EPS exhibits the typical 'U-
shape' published for most cushioning materials. From this shape, the optimal static load around
which a packaging engineer should design is 0.82 Ib/sq inch, which has a corresponding G-force
of approximately 51. To the left of this optimal region, the curve is rather flat revealing good
protective properties even outside the optimal region. To the right, as the load continues to
increase; the EPS sample can no longer absorb the energy of the static load thus resulting in a G-
force that rises quickly.
Figure 15 compares the dynamic cushioning curves of recycled PE foam and EPS. The
first obvious difference between both curves is the optimal region. The optimal region for the
recycled PE foam is at a static load of 0.37 Ib/sq inch, nearly one-third of that of EPS. Though
not much of the recycled PE foam curve extends to the left of this optimal region, to the right the
increase hi G-forces experienced by the pad is not as great as that for EPS. For recycled PE
foam, the static load increased by nearly 300 percent, while the G-force increased by less than 25
percent. This is compared to the G-force experienced.by EPS which increases nearly linearly
with static load (a two-fold increase in static load doubles the experienced G-force). This
suggests that a PE cushion that may be under designed may still perform at the desired level. The
optimal static load for recycled PE foam has a corresponding G-force of 55.
Figure 16 presents the dynamic cushioning curve of two types of starch-based planks:
low-density and high-density. As the baseline, EPS is represented as a dashed line. At the time
this project was initiated, American Excelsior was marketing only the low-density planks. As the
technology developed and the market was assessed, American Excelsior began to manufacture a
22
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high-density plank as well. At this time, only the high-density plank is considered the EcoPlank
product marketed by American Excelsior. The shape of each starch-based material's cushioning
curve is nearly identical, with the only difference being their vertical positioning, or the G-force
corresponding to the optimal static load region. For low-density starch-based planks the optimal
static load is 0.64 Ib/sq inch with a corresponding G-force of 65.6; high-density starch-based
planks had the same optimal static load with a corresponding G-force of 72. These optimal G
force values are considerably higher than that of EPS.
Figure 17 presents the results for a low-density and high-density layered corrugated pad
and compares them to the baseline EPS dynamic cushioning curve. The most intriguin^ feature'
01 this plot is that the G-force corresponding to the optimal static load for the low-density
corrugated material is lower than that of the EPS; specifically, 46 at an optimal static load of 0 5?
Ib/sq inch, while for EPS the G-force is 51 at an optimal static load of 0.82 Ib/sq inch
Theoretically, this means that a flat pad of layered corrugated can protect a more fragile object as
well as a flat pad of EPS. Another unique feature of this plot is that the dynamic cushioning
curve for the high-density corrugated material, though starting extremely high, approaches the
optimal region of EPS as the static load increases. Low-density pads represent Menasha Sus-
Raps standard product; the high-density material was included in this study for completeness to
expand the knowledge of the material, and to determine possible applications.
FIGURE 10 - TYPICAL RESPONSE OF EPS TO SINGLE-EVENT IMPACT SHOCK
60-i
50 -
40 -
30-
20 -
10 -
0-
-10
~"i n i i i i i i i 1 T 1 1 1| 1 j j
52 7.2 92 112 132 152 172 192 212 23.2 25.2 27.2 29.2 31.2 33.2 35.2 37.2 39.2
Time (msec.)
23
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FIGURE 11 - TYPICAL RESPONSE OF RECYCLED PE FOAM TO SINGLE-EVENT
IMP ACT SHOCK
70-
60-
50-
o
| 40-
ฐf
O 30-
20-
10-
0-
-10-
iaa iซ
m 20 23.2 25^
Time (msec.)
aw
33.2 35^ 37^
FIGURE 12- TYPICAL RESPONSE OF STARCH-BASED FOAM PLANKS TO
SINGLE-EVENT IMPACT SHOCK
100 -
80 -
60 -
40
20 H
0
64/1-
-20 -1
T
1
!
7
11
~i r~
13 15
T
T
T
17 19 21 23 25 27 29 31 33 35 37 39
Time (msec.)
24
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FIGURE 13 - TYPICAL RESPONSE OF LAYERED CORRUGATED PADS TO
SINGLE-EVENT SHOCK
70 -
60 -
50 -
40 -
30 -
20 -
10 -
0 -
-10 -
1
T~
7
11 13 15
i
17
i 1
19 21
Time (msec.)
i
23
i
25
27 29
i
31
33 35 37 39
FIGURE 14 - DYNAMIC CUSHIONING CURVE FOR EPS
o
110-
100-
90-
80-
70-
60-
50-
40
Optimal
0.25
0.5 0.75 1 1.25 1.5 1.75 2
Static Load (lb./sq.in.)
2.25
2.5
25
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FIGURE 15 - COMPARISON OF DYNAMIC CUSHIONING CURVES FOR
RECYCLED PE FOAM AND EPS
Drop Height = 30 inches; Sample Thickness = 1.5 inches
110
100 -i
90-
! 80-
i
1 70 -
60-
50-
40
i
Optimal
x
x
X
X
EPS 1
0 'Recycled PHI
i
0.25
0.5
0.75
1.25
1.5
1.75
2.25
2.5
Static Load (Ib7sq.in.)
FIGURE 16 - COMPARISON OF DYNAMIC CUSHIONING CURVES FOR
STARCH-BASED FOAM AND EPS
Drop Height = 30 inches; Sample Thickness = 1.5 inches
no
100 -
90-
a so -
70-
60-
50
40
o
Optimal
0.25 0.5
0.75 1 1.25 1.5
Static Load (Ib./sq.in.)
EPS
0 LDStarch
jfe HDS torch
1.75
2.25 2.5
26
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FIGURE 17 - COMPARISON OF DYNAMIC CUSHIONING CURVES FOR
LAYERED CORRUGATED PADS AND EPS
Drop Height = 30 inches; Sample Thickness = 1.5 inches
180 -
170 -j
160 -j
150 -I
140 -
130 -
120-
uo
100 -
90 ;
80 -
70
60
50
40
30
20
1
/
EPS
LDCorrug.
HDCorrug.
0.25
0.5
0.75
1.25
1.5
1.75
2.25
Static Load (lb./sq.in.)
TABLE 3 - SUMMARY OF OPTIMAL STATIC LOADS AND CORRESPONDING
G-FORCES FOR EACH MATERIAL
Material
EPS
Recycled PE Foam
LD Starch-Based
HD Starch-Based
LD Layered Corrug.
HD Layered Corrug.
Optimal Static Load
(Ib/sq inch)
0.82
0.37
0.64
0.64
0.52
0.93
G-force
51
55
66
72 .
46
56
Note: Drop Height = 30 inches; Sample Thickness = 1.5 inches
ASTM standard methods specify the measurement and recording of a maximum of 5
consecutive drops on the same sample. Reporting the results of such repeated impact absorption,
however, is not required by this method; dynamic cushioning curves typically represent the first
drop impact shock response, as Figures 14 through 17 represent. Packaging design engineers and
industrial specifications often consider the performance of a material under repeated impacts,
however. How a single cushioning material performs under repeated shock impacts will give
some indication of how a cushioning system of a package-product system will perform if, for
example, it was dropped repeatedly onto its side. Table 4 is included in this discussion of
dynamic cushioning to present the decay of each sample's cushioning properties when subjected
to a repeated static load. This table presents the experienced G-force under optimal static load
conditions for each sample for repeated drops. The percent increase of the experienced G-force
for each drop, as compared to the G-force of the first drop, is presented in parentheses.
27
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TABLE 4 - DECAY OF CUSHIONING PROPERTIES FOLLOWING REPEATED SHOCK
IMPACTS AT OPTIMAL STATIC LOAD CONDITIONS
Material
EPS
Recycled PE Foam
LD Starch-Based
HD Starch-Based
LD Layered Corrug.
HD Layered Corrug.
G-force (% Change) Experience During Drop # . . .
1
51.2
55.1
62.6
72.0
48.9
55.6
2
76.9 (50.2%)
59.7 (8.4%)
83.4(27.0%)
81.8.(13.6%)
106.1(131.2%)
86.5 (55.5%)
3
87.3 (70.7%)
61.0 (10.6%)
93.7(42.8%)
86.9 (20.7%)
136.8 (198.2%)
104.1 (87.2%)
4
92.3 (80.4%)
61.8(12.1%)
100.5 (53.2%)
90.4(25.5%)
ND
128.3 (130.8%)
5
94.5 (84.7%)
61.3(11.1%)
106.2(61.8%)
93.6(30.0%)
ND
152.1 (173.5%)
ND: No Data. Experienced G-force exceeded the limits of the computer system settings; data were truncated and an
accurate reading was not recorded.
EPS is used by many consumer product manufacturers for its multiple-impact protective
properties. However, from the results of this study, two alternative materials out-perform EPS in
this regard. Recycled PE foam represents the most resilient material; it is able to withstand
multiple and subsequent shock impacts with as little as 12 percent decay of cushioning
properties. This characteristic of PE foam makes it suitable for reusable/returnable packaging
applications. The starch-based plank product also out-performs EPS after repeated shock
impacts, with a 30 percent and 62 percent decay in cushioning properties for high-density and
low-density starch-based planks, respectively. The results of Table 4 also show a possible
limitation of layered corrugated products. The low-density corrugated pads lost nearly all their
cushioning properties after three subsequent drops, while the high-density material exhibited the
greatest degree of decay at Drop #5 of 173.5 percent.
It should be noted that the results of such tests are highly dependent on the time delay
between subsequent drops, as well as the true distribution environment through which the
package-product system will travel. For the test results presented in Table 4, an average of one
minute transpired between subsequent drops (following ASTM methodologies). It has been
shown, however, that many materials (particularly plastics) have a recovery time of minutes,
hours, and even days. Therefore, the longer a cushioning material has to recover from a single
impact, the better it may perform upon subsequent impact. Furthermore, in typical transport
environments, it is unlikely that a package would experience such frequent impacts, offering the
cushioning material more time to recover.
Extreme Conditions. Two additional test series were performed which evaluated the same
cushioning properties under extreme temperature and humidity conditions. Though typically not
considered an issue for polymeric materials such as EPS and PE, temperature and humidity can
effect the cushioning capabilities of natural materials (i.e., starch and corrugated). Therefore,
two standard conditions were selected for evaluation: desert and tropical. Time constraints did
not allow for the evaluation of the impacts that freezing conditions have on test samples.
Using the results of the first dynamic drop series, a single static load was considered for
each material; this static load was at or near the optimal portion of the dynamic cushioning curve
for each material as presented in Table 3. Therefore, the static loads considered for each material
were as follows: 0.82 Ib/sq inch for EPS; 0.37 Ib/sq inch for recycled polyethylene foam; 0.52
Ib/sq inch for layered corrugated pads; and 0.64 Ib/sq inch for starch-based planks. As before,
28
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three replicate samples at these static loads were tested and the peak G-forces for the first drops
averaged. A comparison of the average G-forces are presented in Table 5. The percent-change
for each recorded average G-force is also presented in parenthesis for Desert and Tropical
Conditions as it compares to the G-force under standard conditions. Supporting data are
published in a separate report, and can be obtained from the U.S. EPA.
TABLE 5 - COMPARISON OF OPTIMAL Gs UNDER EXTREME CONDITIONS
Material
EPS
Recycled PE
Layered Corrugated
Starch-Based Planks
Static Load
(Ib/sq inch)
0.82
0.37
0.52
0.64
Optimal G-forces Recorded Under ...
'Standard' Cond.
51.18
55.13
45.89
65.62
Desert Cond.
53.60 (+4.7%)
59.63 (+8.2%)
45.21 (-1.5%)
72.31 (+10.2%)
Tropical Cond.
49.06 (-4.1%)
58.57 (+6.2%)
67. 14 (+46.3%)
ND
ND: No Data. Due to sample deformation (e.g., shrinkage, brittleness, and delamination), dynamic drop tests could
not be properly performed.
The results of Table 5 show the significant effects temperature and humidity have on a
material's cushioning properties. EPS experienced the least significant change of all materials in
the recorded G-force for both desert and tropical conditions. The +4.7 percent and -4.1 percent
change can be interpreted as insignificant (less than 10 percent of peak G-force) for most
packaging applications. The changes in peak G-forces experienced by the recycled PE samples
are a bit more significant. Under both extreme conditioning environments the recorded G-force
increases, possibly due to the high temperature causing a softening of the polymeric material.
However, as with EPS, the +8.2 percent and +6.2 percent changes can be interpreted as
insignificant for most packaging applications.
The natural cushioning materials were affected much more significantly by the extreme
conditions evaluated in this study. The change in cushioning properties for layered corrugated ,
pads under desert conditions was the least significant for all test materials. This was an
unexpected result due to the fact that an essential ingredient of corrugated pads is moisture; at a
relative humidity of 15 percent it would be expected that most of this essential moisture would
have been lost, causing the pads to become less pliable and therefore resulting in a much greater
G-force. This was not the case, and the corrugated pads experienced the least change (1.5
percent) in cushioning properties under these conditions. On the other side of the humidity
spectrum, too much moisture may cause the corrugated pads to become soggy, reducing the
cushioning potential. This may have been the cause of the results recorded under tropical
conditions (46.3 percent increase in G-force, or decrease in cushioning potential). From these
results, a designer may want to consider the effects of temperature and humidity, and the
conditions under which the package-product system will operate.
Temperature and humidity can play a dominant role in the cushioning properties of
starch-based foams due to the chemical and physical properties of the material. Though not
formally evaluated during this study, material shrinkage and increased brittleness, two common
results of extreme conditions, were both experienced. Qualitatively, under desert conditions the
samples experienced minor dimensional changes; sample area decreased while the thickness
increased due to delamination of the individual layers. The samples were also observed to be
29
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less pliable (i.e., increased brittleness). Under tropical conditions, the change in physical
properties was much more significant. Sample thickness could not even be measured in a
consistent or reproducible manner due to sample distortion and brittleness. Furthermore, the area
of the samples decreased due to shrinkage by over 60 percent. Note that the changes in the
physical dimensions of other materials were considerably less (i.e., percent difference near or
below +/- one percent).
Though the effects of temperature or humidity were not evaluated further in this study,
American Excelsior is currently defining and setting boundary conditions under which their
products are expected to perform adequately. Test results completed by American Excelsior's
starch supplier (National Starch, a division of Unilever) suggest the upper humidity limit is 82.5
percent. Under this relative humidity, with moderate to high temperatures, material deformation
is expected to be minimal. National Starch test results are presented in the supplemental
publication to this report, available through the U.S. EPA.
Supplemental Studies. Prior to this research project, a number of studies were completed and
published by other research organizations on the cushioning properties of selected materials. In
the late 1960's and early 1970's, the Forest Products Laboratory, under the control of the U.S.
Department of Agriculture, published the first studies on the potential applications of layered
corrugated as a cushioning material. Published under a number of titles [22-29], these test series
systematically evaluated different corrugated designs, different pad thicknesses, and different
temperature and humidity conditions. These studies expanded the potential application of
corrugated paperboard beyond the use of boxes. Further studies completed by the same
laboratory evaluated the cushioning offered by the corrugated container itself.[30, 31]
The second prominent and applicable test series addresses the issue of recycled resin
content hi EPS cushioning pads. A study completed by researchers at Santa Clara University in
California presented the effects various recycled resin contents have on the static and creep
properties of EPS.[32] Other publications present results on the dynamic cushioning behavior of
various recycle resin content EPS samples.[33,34] Most revealing about these test results was
that recycled content had little or no effect on the performance of EPS.
Finally, though not considered in this research project, loose-fill cushioning materials
have also been the subject of many other previously completed projects. The most complete and
in-depth study on loose-fill cushioning characteristics was conducted by Michigan State
University. One publication of their results is "Comparison of Various Loose Fill Cushipning
Materials Based on Protective and Environmental Performance."[35]
STRESS-STRAIN TESTS
The ratio of stress to strain is a characteristic constant of a material. The measure of a
material's stress-strain relationship is independent of sample thickness and can be used as a
design parameter for cushioning applications. Stress is defined as the force per unit area
producing deformation hi a body. Strain is defined as the deformation resulting from a stress and
is typically measured by the ratio of the change to the total value of the dimension in which the
change occurred (e.g., percent change of sample thickness). Figure 18 represents the variety of
stress-strain curves which are possible when studying the static characteristics of cushioning
materials. The figure plots the force applied (i.e., stress) and resulting displacement (i.e., strain)
30
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on the y- and x- axes, respectively. An ideal material experiences a constant strain over a wide
range of stresses, as presented by the dashed line in Figure 18.
FIGURE 18 - POSSIBLE STATIC STRESS-STRAIN CURVES
tangent
Force
(stress)
Strain
(displacement)
Apparatus
The apparatus used to evaluate the stress-strain properties of each material was an Instron
1130. This instrument, schematically represented in Figure 19, consists of four primary
components: a load cell, two cross heads, and a strip chart recorder. Capable of analyzing both
tensile and compressive properties of materials, the Instron 1130 was mounted with a
compression load cell for these experimental runs.
FIGURE 19 - SCHEMATIC DIAGRAM OF STRESS-STRAIN TEST APPARATUS
1 load cell
2 reinforced top crosshead
3 moving crosshead
4 change-gear for chart
and crosshead
5 load cell amplifier
6 strip chart recorder
7 crosshead control panel
8 main power switch
9 drive screw
31
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The crossheads of the Instron act as the surfaces between which the material samples are
compressed. The upper, reinforced crosshead contains the load cell, and remains stationary
throughout the test. The bottom crosshead is moved via a drive screw, thus raising the material
sample to the top crosshead. The speed of the drive screw can be set by the user and is controlled
by the crosshead control panel and the gears of the gearbox located in the back side of the unit.
A material sample, placed on the lower crosshead, is raised until its upper surface is just below
the load cell of the upper crosshead. At this time the strip recorder is initiated, the movement of
the lower crosshead continued, and the raw stress-strain data recorded. The features of the
recorded data can be controlled manually by the load cell amplifier and chart control panel.
Procedure
Though standard stress-strain test methods exist for a variety of materials (e.g., food
products and building materials), there is not a standard method that directly applies to
cushioning materials or the goals of this research. Therefore, test procedures were adopted from
the Instron manual and the ASTM methodology C 365-57, Standard Test Methods for Flatwise
Compressive Strength of Sandwich Cores. A step-by-step description of the test procedure
folio wed is included in Appendix B.
Three replicate samples were tested under identical test conditions for four different
materials: EPS recycled PE foam, low-density starch-based plank, and low-density layered
corrugated pads.3 The average of each replicate set represents the stress-strain curves presented
below. Significant differences within replicate sets were not experienced; standard deviations
were well within the tenth percentile as specified in the Quality Assurance Project Plan. Sample
conditioning and test conditions were typical of an office environment: 22 ฐC and 51 percent
relative humidity. After setting and recording the desired chart speed and compression rate, a
material sample was placed between the two compression blocks. As the moving crosshead
raised and began to compress the sample, the graphical chart recorded the stress and strain
measurements of the compressometer. These data were then digitized to develop stress-strain
data files.
Static Stress-Strain Results
When considering stress-strain relationships, an ideal material exists only in theory. As
presented in Figure 18, real materials can exhibit a variety of characteristics. Anomalous
materials exhibit ideal characteristics within a section of the stress-strain relationship, while
tangent and linear materials exhibit few ideal characteristics. Figure 20 presents resultant stress-
strain curves for each of the four materials tested. From this single plot, two distinct curve
shapes can be identified. These results reveal both anomalous and linear characteristics within
the materials tested.
3 Samples of high-density starch-based plank and layered corrugated pads were not available during these
test series. The manufacturers of these materials made high-density samples available to the researchers after stress-
strain tests were completed.
32
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1
CO
GO ฃ
CU o
ซ 1-4
ao
o
O
4>
'S
c
(ra -bs/-q|)
33
-------
The stress-strain curves for the starch-based and recycle PE samples are more linear
throughout the strain range tested, while the stress-strain curves for the EPS and layered
corrugated samples exhibit a 'shoulder,' or yield point, distinguishing two different sections of
the curve (i.e., anomalous materials). The results of the starch-based and PE materials are least
desirable since sample deformation occurs throughout the range of stress. Two distinct
differences, however, can be made when comparing the various slopes of each stress-strain curve
for EPS and layered corrugated.
1. As presented in Figure 18, an ideal material exhibits a constant stress for a wide range of
strains. Compare the slope of each curve prior to the shoulder. The slope for the EPS
samples is much steeper, while that of the layered corrugated material is flatter. EPS
therefore attains a near-ideal profile more quickly, when compared to layered corrugated;
this is a desirable quality of a cushioning material.
2. Next, compare the slopes of each curve after the shoulder. The slope after the shoulder
for layered corrugated is much less (i.e., approaches horizontal) and therefore is
considered more ideal. From the results of this study, low density layered corrugated
pads exhibit the most constant stress level over the widest strain range. This is a
desirable quality of a cushioning materials.
When the project was initiated, and the technical laboratory test series selected, it was
hoped that a relationship could be established between static, stress-strain and dynamic shock
cushioning results. This relationship would establish the foundation for a packaging design
model, or at least design rules-of-thumb for each of the materials. The relationship was to be
established by converting the stress-strain data into stress-force relationships, identical to that of
the G-force versus static load relationships of dynamic cushioning curves. Following the
completion of the static stress-strain tests, data manipulation revealed that the stress-strain results
are rate dependant, or that the resulting strain on the packaging material is a function of the
applied stress and the rate at which it was applied. As a result, a relationship between the
dynamic and static tests could not be established.
Static, stress-strain test results can indicate the amount of set (i.e., compression or
settling) a cushioning system will encounter when burdened with a product. This amount of
compression must be accounted for when designing a package-product system. Minimal set
should occur for those materials exhibiting a shoulder or yield point (e.g., EPS and layered
corrugated pads) for stress-strain relationships below this yield point. Linear materials would
exhibit some degree of set at any stress-strain relationship. The use of static, stress-strain curves
to solve shock cushioning problems is discouraged. [36] Therefore, an evaluation of stress-strain
results beyond that of the theoretical discussion presented above, and the qualitative set
parameter just mentioned, would not offer additional information of use to this study and the
results of the project.
CREEP TESTS
Creep is defined as the amount of set, or compression, a packaging material exhibits
when subjected to a continuous load. Creep can occur in all packaging applications, but is most
prevalent during storage and transport when the protective packaging is under continuous load
34
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from the product, possibly at elevated temperatures. During transport, the agitation resulting
from vehicle movement can add to the existing stresses. As discussed above, stress-strain
relationships can offer a qualitative measure of material set and creep. To extend this qualitative
assessment, rudimentary creep tests were completed for this study.
Apparatus
The apparatus used for evaluating creep is schematically presented in Figure 21. The
apparatus consists of a secured bottom moment-arm plate, free moving top moment-arm plate,
24-inch beam at the bottom of which is mounted a weight plate. Two different packaging
material samples are placed between the top and bottom moment-arm plates. Weighted with the
appropriate load, the apparatus is placed in a temperature controlled oven for the duration of the
study. Two identical apparatus were used in a common oven.
FIGURE 21 - SCHEMATIC DIAGRAM OF CREEP TEST APPARATUS
1 material samples
2 free-moving, top moment-arm plate
3 secured, bottom moment-arm plate
4 weight-bearing beam
5 weight-bearing platform
Procedure
The creep test involves applying a load to each of the four samples for a ten-week period
in a temperature controlled oven at approximately 40 ฐC. Once in the oven, changes in specimen
thickness were recorded after one, two, five, ten, 15, and 20 minutes. Measurements were then
reported at one, two, five, ten, and 15 hours, followed by one, two, five, and seven days. For the
duration of the experiment, measurements of sample thickness were recorded once per week.
Utilizing the results from the stress-strain tests, stress levels were determined for each
material sample (i.e., 5 percent of strain). The following loads were required for each of the
samples in order to operate at the desired 5-percent strain, assuming a 4 x 4 inch square sample;
EPS, 140 Ib; starch-based foam plank, 5 Ib; layered corrugated pads, 68 Ib; and recycled PE foam,
35 Ib. Due to the large variance hi these loads, and the fact that two different samples were being
tested together, sample sizes and moment arms (distance between beam and weights and samples)
were adjusted. A 4 x 4 inch starch-based foam plank sample was paired with a 3 x 3 inch recycled
35
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PE foam sample .with an applied load of 22 Ib. The location of the beam was adjusted resulting in
moment arms that distributed a 3 Ib load to the starch sample and a 19 Ib load to the PE sample.
Similarly, a 3 x 4 inch layered corrugated pad sample was paired with a 4 x 4 inch EPS sample.
The beam and accompanying weight was adjusted to apply an 85 Ib load to the EPS sample and a
38 Ib load to the corrugated sample.
Creep Test Results
The results of these tests revealed that creep is an issue for all materials. The most
significant creep was exhibited by the polymeric materials (EPS and recycled PE foam), while the
layered corrugated pads exhibited the least amount of creep. This creep test apparatus and
procedure was not intended to represent a definitive measure of creep for any of the materials.
This experiment was conducted, and the qualitative results presented in this study for
completeness. For a greater degree of certainty and measure of creep, additional tests are
required.
PROTOTYPE DEMONSTRATION
As stated in Chapter 3, four key considerations must be addressed when designing a
cushioning system: fragility level; distribution environment; impact shock; and cushioning
configuration. The technical results presented above represent the general or generic cushioning
properties and capabilities of each material, i.e., the impact shock considerations under specific
distribution environments. A packaging designer must combine this information with a fragility
level and knowledge of the expected distribution environment to develop an effective and
economical cushioning configuration. How the designer accomplishes this is discussed below.
Cushioning Design
A packaging designer can combine the knowledge of a product's fragility level and weight
with the information supplied by a dynamic cushioning curve to establish guidelines within which
an effective cushioning configuration must be developed. Figure 22 presents how this information
is combined to develop cushioning packaging. Using the calculated bearing area as a guideline, a
package designer can optimize both pad thickness and material use by engineering the
configuration of the cushion. For example, the use of fins in the cushioning configuration can
reduce the quantity of material used while maintaining pad thickness and required bearing area.
The use of fins and other shapes within the configuration of a cushioning system is limited
to some extent by the material(s) used. The processes used to mold EPS pads is very amenable to
a variety of complex shapes, while starch-based planks, recycled PE foam, and layered corrugated
pads require die cutting and separate assembly of parts if fins and other complex designs are used.
This ability or inability to manufacture specific cushioning configurations is a critical issue
affecting the choice of a cushioning material and is addressed in Chapter 6, Economic Evaluation.
36
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FIGURE 22 - THEORETICAL DESIGN OF CUSHIONING PADS - A FOUR STEP
PROCESS
Product Information
Fragility Level = 30 G
Weight = 8 Ib.
Cushioning Material Information
A
40 G
30 G-
20 G-
1"
1.5"
0.3 0.7 1.1
Static Load (lb./sq. in.)
Dynamic cushioning curves for Material X
at a drop height of 30 inches and varying
material thicknesses.
B
With this information, draw a horizontal line
from the fragility level across the plot of
dynamic cushioning curves.
40 G-
30 G
20 G J
1"
1.5"*
2"
0.3 0.7 1.1
Static Load (lb./sq. in.)
Dynamic cushioning curves with optimal
regions below this line represent materials
with thicknesses which offer adequate
cushioning for that particular product; optimal
regions above this line do not offer sufficient
cushioning.
D
To minimize material consumption, design
guidelines should be calculated based on
the dynamic results of the 1.5-inch thick
material. Therefore, the optimal static load
to design towards will be approximately 0.7
lb./sq. in.
To function within this region of the cushion-
ing curve, the weight of the product must be
distributed over a sufficient area (i.e., bearing
area) of cushioning material. Static load is
defined as a known weight distributed over a
specified area. Therefore:
or
static load = weight/area
bearing area = weight/static load
= 81b./(0.71b./sq. in.)
= 11.43sq. in.
The packaging designer uses this as the guide-
line to develop an effective cushioning con-
figuration. The calculated bearing area must
be designed for each side and corner of the
package-product system.
Corner pads, end caps, and planks represent
simple cushioning geometries which offer
sufficient bearing area on all sides to protect
the product. Convolutions, fins, and other
engineering shapes maintain material thickness
and bearing area while minimizing material
consumption.
The center of gravity must also be considered
when designing cushioning systems. More
bearing area of the cushioning system should
be placed under the center of gravity to
absorb the resulting load in that region.
37
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Once a cushioning configuration has been developed, however, the package designer
cannot fully predict how a cushioning system will behave and perform in an actual package-
product application. Therefore, prototype demonstrations must be conducted to evaluate the
performance of designed package-product systems in specific applications. A method to evaluate
the performance of a package-product system has been established by the International Safe
Transit Association (ISTA, formerly the National Safe Transit Association) in the Pre-Shipment
Test Procedures.
This methodology, summarized in Figure 23, has been modified by many manufacturers
to address specific requirements of their products and distribution systems. An example of such
a modification would be to increase the drop height a package-product system must withstand
based on the product's weight, thus increasing the protective demands of the cushioning system.
The standard vibration and drop test sequences of the ISTA Pre-Shipment Test Procedures were
used during prototype demonstrations for this study.
FIGURE 23 - ISTA TEST PROCEDURES FOR PACKAGE-PRODUCT SYSTEMS
WEIGHING UNDER 100 POUNDS
Drop Test
Stepl
Identify and label the following surfaces of the package-product system: top as T; right side
as '2'; bottom as '3'; left side as '4'; front as '5'; and back as '6'.
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.
Identify corners by the numbers of those three surfaces which meet to form that corner. For
example, the corner formed by the right side, bottom, and front is identified as 2-3-5.
The drop height shall be as follows based on package-product system weight: 1 through 20.99
Ib, 30 inches; 21 through 40.99 Ib, 24 inches; 41 through 60.99 Ib, 18 inches; and 61 Ib up to
and including 100.00 Ib, 12 inches, (specifications do exist for heavier products)
Drop or impact the package-product system as specified under Step 4 in the following
sequence: 1) the 2-3-5 corner; 2) the shortest edge radiating from that corner; 3) the next
longest edge radiating from that corner; 4) the longest edge radiating from that corner; 5) flat
on one of the smallest faces; 6) flat on the opposite small face; 7) flat on one of the medium
faces; 8) flat on the opposite medium face; 9) flat on one of the largest faces; and 10) flat on
the opposite largest face.
Inspect both the package and the product. The package-product system shall be considered to
have satisfactorily passed the test if, upon examination, the product is free from damage and
the container still affords reasonable protection of the contents.
Vibration Test
Stepl
Place package-product system on vibration table in the position in which it is normally shipped.
Set the vibration frequency at the minimum speed sufficient to cause the package-product
system to leave the table momentarily so that a shim may be inserted at least 4 inches between
the bottom of the package-product system and the surface of the table.
Vibrate the package-product system for a total of 14,200 vibratory impacts.
Inspect the exterior of the container for visible damage. Check for looseness of product or
components. When practical, inspect the product and then reclose the container.
Source: International Safe Transit Association. "Pre-Shipment Test Procedures - Procedure for Testing Packaged-
Products, Weighing Under 100 Pounds." Revised April 1988.
38
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Prototype Demonstration Results
Each material vendor was asked to identify potential industry partners from their current
and potential clientele which would demonstrate the application of an alternative material. Each
material vendor also had the opportunity to design a packaging system for a VCR currently
marketed by Philips and packaged in EPS end caps. Five separate prototype.demonstrations were
completed within the context of this study:
Two EcoPlank prototype designs for Philips' VCR.
One layered corrugated prototype design for Philips' VCR.
Two EcoPlank prototype designs for a MAYTAG range-top glass component.
The cooperation of a vendor of recycled PE was not obtained in this study; prototype packaging
for performance testing was therefore not obtained.
To establish a baseline for evaluating performance results, performance testing was first
conducted on a VCR packaged in the EPS end caps currently used by Philips. These results are
presented below, followed by a description of each alternative material prototype design and the
results of the ISTA Package-Product System Tests.
Performance of EPS in a VCR Application. As previously stated, VCRs marketed by Philips are
currently packaged with EPS end caps. Two restrictions are placed on any alternative packaging
design if it were to replace this application of EPS:
1.
2.
The prototype cushion-product system must fit into the existing corrugated box to
maintain shipping standards.
Following drop tests, the VCR must function properly as determined by Philips' quality
control department.
Philips has sized each package-product system to optimally utilize available cargo
capacity within various modes of transportation; this is known as "cube efficiency." Therefore,
the first restriction is placed on alternative designs to maintain this cube efficiency. Chapter 6,'
Economic Evaluation, discusses this issue and other economic considerations in more detail.
Though other products manufactured and marketed by Philips require a minimum level of
protection (i.e., a fragility level for the product is specified), such specifications are not placed on
the VCR and the package-product system. As a result, the second restriction above represents
the criterion used to evaluate the performance of a packaging design for the VCR. However, this
qualitative measure of the performance of a package-product system does not allow for a
comparative evaluation between designs. Therefore, to quantitatively measure the performance
of EPS and other packaging designs, a transducer was mounted to the plastic casing of the VCR
and acceleration-time histories were recorded during the standard sequence of drop tests.
Further alterations were made to Philips' testing methods. Philips typically subjects its
package-product systems to drop heights greater than those specified by ISTA (as presented in
Figure 23). To offer performance results based on the internationally accepted ISTA standards,
however, the VCR package-product system was subjected to a drop height of 30 inches (the VCR
weighs less than 20 Ib), rather than Philips' required drop height. The influence of vibration tests
on the effectiveness of a package design is considered minimal by Philips due to the light weight
39
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of the VCR. Vibration tests were therefore omitted from the evaluation of alternative packaging
designs in this application.
Table 6 summarizes the maximum G-forces experienced by the VCR during the drop test
sequence; the measured G-force for each of the six flat surfaces of the package-product system is
presented. The maximum G-force experienced by the product was 142 on the top surface of the
package-product system. This force, as were all the recorded forces, was greater than expected
by the packaging design engineers at Philips. The functionality of the VCR was not
compromised, however, and the design is therefore acceptable. The values in Table 6 are used to
quantitatively compare the performance of each prototype design to that of the EPS end caps.
Data resulting from the corner and edge drops are not presented in Table 6 due to their
irrelevance to the overall evaluation. The transducer was mounted to the front or back of the
VCR. As a result, corner and edge drops do not have a dominant axis of motion; energy is
displaced across two or more axes, and therefore does not result in maximum resultant force or
offer relevant information to the overall performance of the package design.
TABLE 6 - QUANTITATIVE PERFORMANCE ASSESSMENT OF EPS END CAPS
Impact Surface
Maximum G-Force
Left Side
89
Right Side
112
Front
73
Back
100
Bottom
110
Top
142
First EcoPlank Prototype for the VCR. American Excelsior was asked to design a cushioning
system for Philips' VCR currently packaged in EPS end caps. Following the restrictions placed
on the design by Philips, the first of two cushioning systems designed by American Excelsior can
best be described as edge pads. Two L-shaped pads protect the left and right bottom edges of the
product by running from the front of the box to the back; the VCR is centered on these pads and
two additional L-shape pads protect the front and back edges of the product by running from left
to right.
Dynamic drop tests were run on this starch-based prototype package-product system. The
package-product system was dropped from a height of 30 inches on the ten surfaces identified in
Figure 23. Minimal deterioration of the cushioning system was identified following this test
series; each L-shaped pad was still fully intact. Inspection of the VCR case showed no
appreciable damage either. Inspection of the VCR by QC personnel, however, revealed internal
damage to the working electronics of the unit. Running through a series of QC checks, each
function of the VCR operated as designed (fast forward, rewind, play, pause, etc.) until the record
function was tested. When recording on a used cassette, a visual image could be recorded, but
the sound was not. In fact, the sound corresponding to the last image taped on the cassette still
remained. Therefore, the electronics which erase and record sound were damaged. Though
considered a minor failure, this first prototype packaging design did not pass the required test
procedures.
40
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Unfortunately, acceleration-time histories during drop tests were not accurately
recordedby the computer data acquisition system; transducer readings were inadvertently
truncated by the computer system and the actual maximum G-forces for each flat-surface drop
could not be determined. Based on estimates, however, a maximum G-force of nearly 200 was
recorded when the package-product system was dropped onto its top surface. This value exceeds
the maximum G-force experienced during package-product system drops which employed EPS,
and thus may have caused the functional failure of the VCR.
The package-product system was therefore evaluated to identify possible improvements.
The primary area of improvement identified was in terms of bearing area. The bearing area
offered by the prototype design was too large considering the weight of the VCR and the results
of dynamic drop tests during this study. Based on these observations, and the continued interest
of Philips and American Excelsior in this evaluation, a second prototype design was developed.
This new prototype design optimized bearing area and material usage.
Second Starch-based Prototype for the VCR. The second cushioning system designed by
American Excelsior combined EcoPlank pads and a corrugated substrate into a design
schematically represented hi Figure 24. Five separate EcoPlank pads were glued to a single sheet
of corrugated which served to position the pads in the proper locations around the VCR. Two
such EcoPlank/corrugated pads composed a functional unit, one pad for each side of the VCR.
Figure 24 shows the two separate corrugated substrates (dashed lines) and the position of only
five of the ten total Eco-Plank pads; each substrate surface has an EcoPlank pad attached to it.
FIGURE 24 - SCHEMATIC OF SECOND ECOPLANK PROTOTYPE DESIGN
FOR VCR
Key:
= corrugated substrate
= starch-based foam pads, five on each substrate
Dynamic drop tests were run on this starch-based prototype package-product system. The
package-product system was dropped from a height of 30 inches on the ten surfaces identified in
Figure 23. Again, minimal deterioration of the cushioning system was identified following this
test series. Inspection of the VCR case showed no appreciable damage either. Inspection of the
VCR by QC personnel revealed no damage to all functions of the VCR. Internal inspection of
circuit boards and other electronics did not reveal any damage either.
41
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Quantitatively, the G-forces recorded for this application of EcoPlank were comparable to
those recorded for the application of EPS cushioning. These figures are presented in Table 7.
Though the G-force experienced by the VCR on the top drop exceeded that of the EPS design,
the functionality of the product was not sacrificed and the design passed the imposed
requirements. The prototype design, therefore, satisfied all relevant tests and restrictions placed
on it by Philips.
TABLE 7 - QUANTITATIVE PERFORMANCE ASSESSMENT OF ECOPLANK
PROTOTYPE DESIGN
Impact Surface
Left Side
Right Side
Front
Back
Bottom
Top
Maximum G-Force
73
70
76
54
99
152
Layered Corrugated Prototype for the VCR. Menasha Sus-Rap was also asked to design a
prototype package for the VCR. Encouraged by the performance of layered corrugated pads in
the dynamic tests (i.e., lower optimal G-force than EPS), an effective prototype design for the
VCR was considered possible. Conforming to the restrictions established by Philips, and applying
similar design features used hi many furniture applications, Menasha designed a cushioning system
consisting of two U-shaped channel pads that surround each end of the VCR. Each channel pad
is notched to allow the pad to bend around the VCR corners. Flat pads are sparingly used to fill
the void space between the channel pads and the corrugated box. The channel design is
schematically represented in Figure 25.
FIGURE 25 - SCHEMATIC OF LAYERED CORRUGATED PROTOTYPE DESIGN
FOR VCR
notches which allow pads to bend
top
left side
~7
right side
\
\
bottom
42
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This prototype package-product system was dropped from a height of 30 inches on the ten
surfaces identified in Figure 23. Though the cushioning system noticeably deteriorated as a
result of this drop series, an inspection of the VCR showed no appreciable external damage.
Inspection of the VCR by QC personnel revealed no damage to all functions of the VCR.
Internal inspection of circuit boards and other electronics did not reveal any damage either. The
prototype design, therefore, satisfied all relevant tests and restrictions placed on it by Philips.
Quantitatively, the G-forces recorded for the application of layered corrugated pads were
comparable to those recorded for the application of EPS cushioning. These figures are presented
in Table 8.
TABLE 8 - QUANTITATIVE PERFORMANCE ASSESSMENT OF FIRST LAYERED
CORRUGATED PROTOTYPE DESIGN
Impact Surface
Left Side
Right Side
Front
Back
Bottom
Top
Maximum G-Force
73
62
112
105
ND
98
ND: No Data. Acceleration-time data were truncated by computer system resulting in an unknown peak
Though the bearing area of the prototype design was not optimal (as much as 5.5 times
greater than theoretically required based on this study's dynamic test results) the cushion system
functioned adequately. Optimization of this design would include reducing the bearing area.
This change would reduce the amount of material used, thus reducing cost and potentially
improving the performance of the packaging. Due to time restrictions, the optimization of this
design was not possible within the contexts of this project.
First EcoPlank Prototype for MAYTAG's Glass Component. MAYTAG operates a distribution
facility in Milan, Tennessee which supports (i.e., supplies parts to) the customer service needs of
MAYTAG, Admiral, JENN-AIR, and Magic Chef across the country. Receiving most of the
parts and materials in bulk from the manufacturers, the distribution facility is responsible for
individually packaging single-unit orders requested by service representatives. Protective
packaging of fragile parts is accomplished using a variety of packaging materials including
polyethylene foam plank, EcoFoam loose fill, plastic bubble pack, and crinkled-up newsprint.
Ineffective packaging of tempered glass panels is a current problem at MAYTAG. These
tempered glass panels are replacement parts for kitchen ranges (tops, control panels, etc.), and
come in a variety of shapes and sizes. Bubble pack or corrugated pads are currently the typical
materials selected to package these parts for distribution. The rate at which these parts are
damaged during shipment, however, is quite high. The cost of this damage is one of the highest
within this facility for a particular product line. As a result, MAYTAG was interested in testing a
variety of design options, and agreed to test EcoPlank on one line of glass panel - a long, narrow
control panel. Beyond effectiveness and cost, there were no restrictions placed on American
Excelsior for this prototype design.
43
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Due to the current rate of failure experienced by MAYTAG, American Excelsior
approached this situation from the side of over design; once a passing design was proven
effective, optimization of material use and package size could follow. The first prototype design
for the control panel utilized a great deal of EcoPlank to protect the top and bottom of the glass.
The glass panel itself was nestled in a die-cut sheet of foam sandwiched between the top and
bottom pads. Though the test results of this initial design were positive, improvements were
possible that would minimize package-product size and material usage. The optimal design and
further test results are presented below.
Second EcoPlank Prototype for MAYTAG's Glass Component. Center staff met with
MAYTAG and American Excelsior representatives to discuss the initial design and test results,
and to identify design features which could be optimized. From this discussion, three significant
changes were suggested and implemented. The changes better utilized the cushioning strengths
of EcoPlank, and reduced pad volume by nearly 75 percent. The final design consists of two end
caps which support the glass panel on all sides, and two pads that run along the top and bottom of
the panel to absorb vibrations. Figure 26 schematically represents this new design.
FIGURE 26 - SCHEMATIC OF FINAL ECOPLANK PROTOTYPE FOR MAYTAG'S
GLASS PANEL
bottom
The results of this optimized design were positive. The optimized prototype package-
product system was first subjected to vibration tests at 220 cycles per minute for one hour.
Following vibration tests there was no observed degradation of the cushioning material, and the
glass panel remained tight within the package. The package was then subjected to the standard
series often drops (i.e., dynamic impact tested) from'a height of 30 inches. The glass panel did
not break. Inspection of the cushioning system revealed little deterioration; the pad on the end of
the package-product system which suffered the corner and three edge drops was slightly
deteriorated, but significant cushioning potential still remained.
Other Applications. A number of journal articles have presented other applications of alternative
cushioning material to replace EPS and other packaging material. For completeness, and to
demonstrate additional opportunities for each alternative material, specific applications of
alternative packaging materials have been included here.
44
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"Electronics Challenge: Pack It Safe and 'Green'" summarizes the reasons for the trend
towards more environmentally friendly packaging and identifies an application of
Hexacomb's kraft-paper product Cushion-Comb to package Epson's ActionNote 700C,
their latest notebook computer. [3 7]
Barbara McDaniel of Rosemount Inc., incorporated die-cut honeycomb and corrugated
kraft paper to protect a uniquely shaped electronic transmitter. This design won the
Environmental Award in the 1994 AmeriStar Competition. [38]
Norel Paper, in conjunction with Enpac developed Enviromold, a starch-based,
biodegradable mold-in-place packaging system which is used to package stereo
equipment. [3 9]
American Excelsior has designed an effective and efficient protective packaging system
out of EcoPlank for a mail-order wine distributer located in California. This distributor
replaced its existing EPS design for the more environmentally benign EcoPlank material.
Another design using EcoFoam pads was presented in a recent issue of Packaging
Technology & Engineering. "To improve product protection, decrease costs and upgrade
aesthetics, Mr. Coffee has switched from corrugated and bubble wrap to American
Excelsior's starch Sheets and Planks as an environmentally-sound packaging
alternative."[40] Advantages to the new design include a single vendor, anti-static
packaging material, and an easily disposable packaging product.
CONCLUSIONS
The results of the technical evaluation reveal the strengths and weaknesses of each
protective packaging material. While the results of dynamic tests were utilized in prototype
development, the applicability of static, stress-strain tests was not identified. Prototype
demonstrations using starch-based foam and layered corrugated pads show the ability of these
alternatives to replace EPS as a cushioning packaging material.
Under standard temperature and humidity conditions, dynamic drop test results revealed
positive cushioning characteristics of each material. Using samples of 1.5 inch thick, layered
corrugated pads offered as much protection as EPS for a single drop; starch-based foam and
recycled PE foam displayed lesser protective characteristics. Starch-based foam and recycled
polyethylene foam did display a greater ability to absorb the energy resulting from multiple drops
than that of EPS. High temperatures and extremes in humidity seem to have the most significant
impact on starch-based foam, causing sample deterioration which resulted in decreased
cushioning ability.
Test results from dynamic drops (i.e., cushioning curves) were used, in conjunction with
design expertise, to develop effective prototype protective packaging designs. EPS, while
adequately protecting the consumer product from damage, did not perform to expected levels.
Prototype designs using layered corrugated pads and starch-based foam also protected the
consumer product from damage, and performed to a level comparable to that of EPS. In
applications for glass packaging, starch-based foam prototype designs again revealed positive
protective properties of EcoPlank.
45
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CHAPTER 5
ENVIRONMENTAL EVALUATION
The primary objective of the environmental evaluation was to analyze the releases and
transfers of 33/50 chemicals resulting from the use of EPS as a cushioning material, and to
compare these to the releases and transfers associated with a similar application of the alternative
cushioning materials. The use of packaging materials by product manufacturers, however, does
not result in the direct release or transfer of the 33/50 chemicals. For example, releases and
transfers of the 33/50 chemical benzene will occur during the chemical conversion of benzene
into ethyl benzene, but do not occur during the manufacture of an EPS cushioning material or its
application in packaging. Therefore, a life-cycle perspective was applied during this
environmental evaluation to capture the potential life-cycle emissions of 33/50 chemicals
resulting from the use of each packaging material. This life-cycle perspective results in a
qualitative and quantitative evaluation of chemical releases resulting from raw materials
extraction, processing, and disposal.
The environmental evaluation revealed that most 33/50 chemical releases and transfers
occur prior to package manufacturing, use, and disposal. 33/50 chemical releases to the air and
water are expected for the pre-manufacturing processes of EPS, starch-based foam, and PE resin
(if petroleum is used). The most significant difference identified in the package manufacturing
processes was the possible elimination of the VOC (pentane) emission resulting from EPS
production; few, if any VOC releases result from either starch-based foam or layered corrugated
pad manufacturing. Finally, various disposal options were identified for each material that may
be better suited for each material than disposal in a landfill. These results are discussed in detail
in this chapter.
PRODUCT LIFE-CYCLE
Life-cycle assessment (hereafter LCA) is a comprehensive concept and methodology for
evaluating the environmental and human health burdens associated with a product, process, or
activity. The life-cycle of a product includes the basic stages of raw materials acquisition,
manufacturing, use/reuse/maintenance, and recycling/waste management. A complete LCA
identifies inputs and outputs from each life-cycle stage (inventory); assesses the potential impacts
of those inputs and outputs on ecosystems, human health, and natural resources (impact
assessment); and identifies opportunities for achieving improvements (improvement
assessment). [41]
A complete and comprehensive LCA was beyond the scope of this study. Key life-cycle
concepts and issues, however, must be identified and discussed to assess the potential
environmental impacts resulting from the application of the evaluated packaging materials.
Three broadly-defined life-cycle stages were used to represent the product life-cycles for each
packaging material: pre-manufacturing, package manufacturing, and waste management. The
remaining sections of this chapter discuss environmental impacts from these three life-cycle
stages.
To evaluate the environmental burdens associated with the use of each cushioning
material, and to allow a comparison of inputs and outputs between materials, the equivalent use
46
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of the material must be considered. When considering cushioning materials in a particular product
application, equivalent use can be defined as the amount of each material required to accomplish
the same level of production. The equivalent use of each material was determined using the
cushion configuration designed for the VCR described in the prototype demonstrations. To
maintain the confidentiality of the information gathered from each material manufacturer,
however, actual materials use is not explicitly stated in this discussion. Rather, for each VCR
packaging system, the quantity of cushioning material used is considered 'one unit' and all inputs
and outputs are calculated from that unit.
PRE-MANUFACTURING LIFE-CYCLE STAGES
Pre-manufacturing is defined here as the unit operations that are required to supply raw
materials to the package manufacturing life-cycle stage. The primary pre-manufacturing unit
operations and resulting environmental releases and transfers are discussed for each material
below. The 33/50 chemicals are the focus of the discussion in the pre-manufacturing stage, due to
the nature of the packaging materials (i.e., releases occur prior to package manufacturing, use,
and disposal).
Expanded Polystyrene
Polystyrene resin used in most EPS applications across the country is manufactured from
virgin raw materials. Though EPS is a thermoplastic and can be readily recycled, economics has
limited its collection and use as a recycled raw material (see Waste Management Life-Cycle
Stages below). Therefore, the production of virgin polystyrene resin, presented in Figure 27,
represents the pre-manufacturing life-cycle stage for EPS.
Benzene, produced from crude oil, and ethylene, produced from either crude oil or natural
gas, represent the chemical raw materials which begin the pre-manufacturing unit operations
which produce EPS. Benzene and ethylene react to produce ethyl benzene. Styrene monomer is
produced from ethyl benzene and is then polymerized to produce polystyrene (PS) resin. PS resin
is combined with a blowing agent, typically pentane, to produce PS beads. The incorporated
pentane expands when heated and facilitates'the formation of EPS products. PS beads is the raw
material which enters the package manufacturing life cycle.
From this pre-manufacturing life-cycle stage, a number of 33/50 chemical releases and
transfers can be expected. The production of benzene from crude oil results in emissions of
benzene, as well as toluene and xylene, two other 33/50 chemicals which are typically converted
to benzene (see Figure 1). The production of ethyl benzene from benzene and ethylene results in
benzene emissions as well. Potential emission factors established for these processes support this
conclusion; benzene is the top chemical pollutant emitted to both air (1.93 Ib benzene to air per
ton PS produced) and water (3.79 x 10'3 Ib benzene to water per ton PS produced).[42] These
values represent controlled emission factors and do not include environmental burdens resulting
from energy production and consumption. The production and use of process energies would
also contribute to these potential emission factors. The energy requirements to manufacture one
ton of PS from raw materials extraction to polymer is 39.4 MBTUs. [43]
47
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Starch-Based Foam Plank
Pre-manufacturing unit operations for starch-based foam include the agricultural
production of a starchy crop (e.g., corn or potatoes) and the extraction of starch from this crop.
For the purposes of this study, corn will represent the starchy crop. This is consistent with the
starch-based foam plank of American Excelsior which is manufactured primarily from modified
com starch. Figure 28 schematically represents the pre-manufacturing unit operations for the
production of starch from corn.
The cultivation of corn by typical methods requires the application of chemical additives
such as herbicides, insecticides, and fertilizers. Herbicides were applied to 96 percent of the corn
acreage in 1995. The most widely used herbicides for corn production in 1995 included'atrazine,
metolachlor, and cyanazine.[44] Insecticides were applied to 28 percent of the acreage in 1995
with chlorpyrifos and terbufos being the most wide spread. Although these herbicides and
insecticides are applied at a low rate relative to the production of corn (e.g., 3.74 x 10'5 Ib
atrazine/lb of corn harvested [45]), their production processes should be considered as a part of
the pre-manufacturing life cycle of the starch-based foam.
Atrazine is used here to illustrate agricultural chemical production because it is the most
widely used herbicide for corn production with use on 65 percent of the reported acreage. Figure
29, a simple flow diagram for the production of atrazine, shows the 33/50 chemical hydrogen
cyanide as a chemical raw material in the production process. Information is not available which
relates this use of hydrogen cyanide to releases of 33/50 chemicals per ton of starch (or corn)
produced. However, it must be acknowledged that this use of a 33/50 chemical exists and
releases are possible.
Fertilizers used for corn production include nitrogen, phosphates and potash, and are also
major inputs to corn production. Nitrogen, for instance, is typically applied at a rate of about 4.3
x 10"3 Ib/lb of corn harvested. [46] Over 95 percent of all commercial nitrogen fertilizer is
derived from synthetic ammonia, produced from natural gas; essentially all phosphate is derived
from mineral phosphates; potash is a mined potassium salt. [47] The production of these
fertilizer inputs are not expected to result in the use or release of 33/50 chemicals.
To plant, cultivate, harvest and dry an agricultural crop such as corn, petroleum fuels and
electricity are required to operate heavy agricultural machinery. It has been estimated that 24,000
BTU of energy are consumed per bushel of corn produced. [48] Assuming average corn yields,
this translates to a fuel consumption rate of approximately 15 gal of petroleum per acre per year
for planting, cultivation and harvesting, and approximately 460 standard cubic feet of natural gas
per acre per year for drying. Though direct correlations from this rate of fuel consumption to the
quantity of starch produced from corn are not available, it must be acknowledged that the use of
petroleum fuels will result in the release of 33/50 chemicals during the refining process,
machinery fueling, and possibly combustion.
After cultivation, starch separation from corn kernels is accomplished by the wet-corn
milling process. As shown in Figure 28, this process consists of screening, to remove the corn
from the cob and other impurities; corn steeping, to soften corn kernels and promote component
separation; grinding; and separation, such as centrifugation and cyclone washing, to remove the
starch from other kernel components. Wet-corn milling is a water intensive process; 20 gallons
of water are required for each 100 pounds of corn processed. Centrifugation and drying are used
to remove this water from the final starch product. As a result, wet-corn milling is the second
most energy intensive food industry in the United States. [49] The only chemical additive within
49
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this process scheme is sulfur dioxide in the steeping process; sulfur dioxide controls microbial
growth in the aqueous bath and facilitates water absorption into the corn kernel. Therefore,
33/50 chemical releases are not expected from these pre-manufacturing processes of starch-based
material.
Layered Corrugated Pads
Layered corrugated pads manufactured by Menasha Sus-Rap are produced entirely of 100
percent post-consumer recycled material. The collection of waste paper thus begins the
corrugated pad pre-manufacturing life-cycle chain, as shown in Figure 30. Once wastepaper is
received at the paper mill, it is repulped through mixing with heated water in a hydropulper
which pulverizes the waste paper, separating the paper fibers and creating a fiber pulp slurry.
Through various purification steps (e.g., flotation, centrifugation, and magnetic screening),
impurities such as plastics and staples/paper clips are removed from the pulp slurry before
entering the kraft paper production process. For corrugated medium, deinking and bleaching is
typically omitted from this production process. To produce the desired corrugated
characteristics, rosin, alum and starch are added to the pulp slurry during the kraft paper
manufacturing process. Chemical processing aids are also added to the slurry pulp to control
factors such as foaming.
FIGURE 30 - PRE-MANUFACTURING LIFE-CYCLE STAGE FOR LAYERED
CORRUGATED PADS
Kraft Paper
Key: a. Repulping- grinding of waste paper with water to create pulp slurry
b. Cleaning - removing impurities such as plastics and metals through floatation, magnetization, and
sedimentation
c. Kraft paper production - with the addition of alum, rosin, and starch to pulp slurry kraft paper is
produced (Note: Additional processing chemicals may be added)
From this pre-manufacturing process description there are few, if any 33/50 chemical
releases to the environment expected.4 This expectation was supported by facility-specific data
collected from a recycled paper supplier to Menasha. Published controlled emission factors for
recycled corrugated medium, however, suggest that zinc is the most significant 33/50 chemical
emission to water from these processes: 2.15 x 10'2 Ib zinc to water per ton corrugated medium
produced.[50] This contaminant may be a result of the inks used on the waste paper collected for
recycle. The use of zinc and other heavy metals in ink has been greatly reduced over the years; it
4 For this study, the environmental burdens resulting from the production of paper from virgin wood pulp,
and the initial use of paper products, are not considered as part of the burdens of the recycled material. There are
methods for allocation of virgin material impacts for recycling loops in the LCA field, but such methods are beyond
the scope of this project.
52
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is possible this emission factor reflect such dated information. There are no reported 33/50
chemical emission factors to air.
These emission factors do not include environmental burdens resulting from the
collection of waste paper for recycling, nor energy production or consumption. The energy
required to manufacture one ton of recycle corrugated medium is 17 MBTUs. [51J The
production and use of these energy sources could also contribute to the 33/50 chemical emission
burden.
Recycled PE Foam
The recycled PE foam evaluated within this study is manufactured from both virgin and
recycled material, in a ratio of 80 percent virgin to 20 percent recycled resin (typical ratio for
recycled PE foams). To assess the environmental burdens for the pre-manufacturing life-cycle
stages, both virgin and recycled polyethylene resin manufacturing activity must be evaluated.
For simplicity, however, 100 percent virgin PE resin will represent the produced material in the
pre-manufacturing processes for the PE foam evaluated in this study. This assumption most
likely over-estimates the emissions resulting from pre-manufacturing processes of recycled PE
foam. The use of recycled resin reduces the demand for virgin material, thus reducing crude
oil/natural gas extraction and refining burdens. The energy required to process PE resin is less
than the energy required to produce virgin resin from natural gas or crude oil. [52]
The pre-manufacturing unit operations for 100 percent virgin PE resin are presented in
Figure 31. Ethy lene is manufactured from the cracking of ethane, propane, and butane produced
from either natural gas or petroleum naphtha. Ethylene is then polymerized under high
temperatures and pressures to produce polyethylene resin. As with PS resin production from
petroleum feedstocks, emissions of the 33/50 chemicals benzene, toluene, and xylene are
expected; no emissions of 33/50 chemicals are expected from the refining of natural gas.
Controlled emission factors for the production of low-density polyethylene identify benzene,
toluene, and xylene as the only 33/50 chemical emissions to air: 1.80 x 10'1 Ib benzene/ton PE;
2.53 x 10'2 Ib xylene/ton PE; and 7.00 x 10'3 Ib toluene/ton PE. Though benzene and toluene are
also emitted to water (1.49 x 10'2 Ib/ton, and 1.44 x 10'2 Ib/ton, respectively), the 33/50 metal
chromium tops the emission factors to water at 3.03 x 10'2 Ib chromium/ton PE produced. The
production and use of process energy, though not included, would also contribute to these
emission factors. The energy required to manufacture one ton of PE resin 39.9 MBTU.[53]
FIGURE 31 - PRE-MANUFACTURING LIFE-CYCLE STAGE FOR RECYCLED PE
FOAM
Key:
Refining (a)
Polymerization (b)
Polyethylene
a. Refining - production of ethylene from natural gas or crude oil
b. Polymerization - production of polyethylene from ethylene monomer
53
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PACKAGE MANUFACTURING LIFE-CYCLE STAGES
Facility-specific information was gathered from the manufacturers of three of the
cushioning materials. Questionnaires, distributed by mail, introduced each manufacturer to the
project, described goals of the environmental evaluation, and gathered data in three primary areas:
raw materials, energy requirements, and waste streams. Questionnaires were formatted
specifically for each manufacturing process; an example questionnaire is presented in Appendix C,
and represents the questionnaire distributed to Tuscarora, the EPS packaging manufacturer for
Philips.
Site visits to each manufacturing facility were conducted following the completion of the
questionnaires. The purpose of each site visit was to become more familiar with the
manufacturing process, to ensure the questionnaire gathered information for the entire
manufacturing process, to judge whether the supplied information was reasonable, and to clarify
any questions that may result from the interpretation of the completed questionnaires. With this
information, facility-specific environmental profiles were developed for each material on a per-unit
basis.
Unfortunately, the recycled PE foam manufacturer chose not to participate in the
prototype demonstrations or the environmental profiles. Therefore, facility-specific information
will not be presented for this material.
EPS Package Manufacturing
EPS is used as the cushioning material in all of Philips' packaging applications. Tuscarora
is the sole supplier of this cushioning material for the Philips manufacturing facility in Greeneville,
Tennessee. Tuscarora manufactures a number of packaging products including EPS products,
corrugated products (both paper and plastic), and EPS-corrugated composites. Data collected by
the completed questionnaire and site visit were for the EPS cushion manufacturing operations.
Polystyrene (PS) beads are the raw material entering Tuscarora's cushion manufacturing
facility. The beads are delivered in 1,000 Ib totes from a BASF production facility located either
in Ohio or New Jersey. From these totes, the beads are transferred directly to one of two pre-
conditioning units. Pre-conditioning heats the beads with steam causing the encapsulated pentane
to expand, thus expanding the PS beads to approximately 50 percent of their final volume in the
EPS product (in the final product, PE beads expand nearly eight times their original size). By
controlling the amount of heat delivered, and therefore the amount of expansion, the density of
the final EPS product is controlled. The pre-conditioned beads are then stored for a short time
(i.e., less than 12 hours) in large equalization hoppers, where they are drawn off and delivered to
the molding process units.
At Tuscarora the molds which form the desired cushioning configurations are fabricated
out of aluminum and coated with a non-stick layer of Teflonฎ. The aluminum molds are hollow,
allowing water to pass through the inner core of each unit to cool the molded EPS product. Pre-
conditioned PS beads are injected into the cushioning configuration molds along with steam. The
delivered steam bonds the beads together and completes the bead expansion process by heating
the polymer and expanding the remaining pentane encapsulated in the beads. The continuous,
closed-loop flow of water cools the EPS product before it is removed from the mold. This entire
process is automated and computer controlled; manual labor is used to change the aluminum
molds and to stack and pack the EPS products ejected from the processing units.
54
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According to Tuscarora's representative, these EPS molding units are the largest in the
world and represent a unique advancement in the EPS molding industry. Typical EPS molding
processes use stainless steel molds, the application of steam within the core of the mold to heat
the injected beads and complete the expansion process, and the application of cooling water into
the same mold core to cool the product prior to extraction. Each cycle of the process heats the
mold to 105 ฐC, followed by a rapid water-cooling step to a mold temperature of 88 ฐC. This
typical EPS molding process is slow and energy intensive. The combination of the Teflonฎ
coated aluminum molds, steam delivery solely to the PS beads, and continual closed loop cooling
with water used in Tuscarora's molding operation reduces energy use and water consumption by
25 percent when compared to the typical process units.
Table 9 presents Tuscarora inventory data developed from the completed questionnaire
and facility site visit. To maintain confidentiality, the information is presented in terms of
equivalent use (i.e., the quantity of material required to protect a VCR).
TABLE 9 - INVENTORY OF INPUTS AND OUTPUTS FOR EPS CUSHION
MANUFACTURING
Category
Raw Materials
Energy Requirements
Wastes
Input or Output
EPS Beads (e/pentane)
EPS Regrind
Electricity
Natural Gas
Solid, Non-Hazardous Waste
Hazardous Waste
Wastewater
Air Emissions
Quantity
one unit
1.29 g/unit (2.8 x 10'3 Ib/unit)
0.101 kW-hr/unit (3 .45 x 1 02 BTU/unit)
1.52 x 10'5 SCF/unit (0.03 BTU unit)
1.42xlO-7lb/unit
0
8.20 x 10'3 gal/unit (0.01 Ib/unit)
2.45 g/unit (5.4 x 10'3 Ib/unit)
The solid waste generated during the manufacture of EPS packaging contains primarily
waste EPS (e.g., loose beads and broken EPS parts) and process wastes such as miscellaneous
boxes, shrink wrap, and binding twine. A small percentage of the waste EPS is incorporated as
regrind back into the packaging products. The remaining wastes are disposed of at a local
municipal solid waste (hereafter MSW) landfill. The wastewater, primarily condensate water
from the boilers used to heat the various process units with steam, is disposed of down the sewer
drain where it enters the local Publicly Owned Treatment Works (hereafter POTW). No data
were available on the composition of the wastewater. Finally, the air emissions from the process
are exclusively pentane emitted from the EPS beads during the expansion process.
Starch-Based Foam Package Manufacturing
American Excelsior's facility in Lonbard, Illinois is currently the only location
manufacturing the Eco-Plank cushioning product. The starch raw material is delivered to this
facility in 2,000 Ib totes via rail or tractor-trailer trucks from National Starch (a division of
Unilever) located in Bridgewater, New Jersey. From the totes, the starch is transferred to
hoppers which gravity-feed the starch into the primary processing unit This primary unit is a
horizontal-screw extruder, similar to those typically used in the food processing industry. Starch
is delivered to one end of the extruder. The horizontal screw moves the starch along the length of
55
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the unit while mixing in water and a small amount of soybean oil under conditions of elevated
temperature (near 150 ฐC) and pressure. A continuous starch-based foam sheet is formed when
the starch mixture is forced through a small plate opening in the opposite end of the extruder,
causing the water to instantly vaporize into steam when exposed to atmospheric/ambient
conditions. This sheet has a fluted appearance (or S-shape) as a result of the shape of the plate
opening.
The continuous foam sheet leaving the extruder is cut to length by a guillotine cutter and
enters a series of rollers. A thin layer of water-based, starch adhesive is added to one side of the
sheet at the final roller. The individual sheets are then manually stacked to assemble the standard
planks. Foam sheets are combined in this manner until enough layers have been combined to
produce a plank of the desired thickness. The plank is then passed through a conveyor system
which compresses it slightly to ensure adequate contact between layers and consistency in plank
thickness. Planks can range in thickness from a single foam sheet of 1/4 inch to any thickness in
1/4 inch increments; the standard plank manufactured is 2 inchs thick. Sheets of lesser thickness
which are not fluted are also possible. Cushioning products are produced by manually cutting
various shapes from these planks and assembling them into the appropriate configuration. Table
10 summarizes the inventory input and outputs for this process, based on equivalent use (i.e., the
quantity of material required to protect a VCR).
TABLE 10 - INVENTORY OF INPUTS AND OUTPUTS FOR STARCH-BASED
FOAM PLANK MANUFACTURING
Category
Raw Material
Energy Requirements
Wastes
Input or Output
Starch
Water-Based PVA Adhesive
Soybean Oil
Other Additives (e.g., talc)
Electricity
Natural Gas
Solid, Non-Hazardous Waste
Hazardous Waste
Wastewater
Air Emissions
Quantity
one unit
9.9 x 10'3 gal/unit (8.3 x 10'2 Ib/unit)
8.89 g/unit (2.0 x 10'2 Ib/unit)
1.55 g/unit (3.4 x 10'3 Ib/unit)
1.37 kW-hr/unit (4.7 x 103 BTU/unit)
0
9.4 x 10 -2 Ib/unit
0
1.02 x 10'2 gal/unit (8.54 x 10'2 Ib/unit)
0
The wastes resulting from the manufacture of starch-based foam materials are minimal.
The non-hazardous, solid waste stream, which dominates the outputs from American Excelsior,
consists of waste starch material, as well as other process debris such as empty containers, bags,
and twine. This material is disposed of at a MSW facility. The wastewater effluent consists of
non-contact water used to heat the extruder, which is drained during each process shut-down.
This wastewater is discharged to the sewer and is treated by the local POTW; composition data
on this wastewater were not available. American Excelsior data identified no other waste streams
resulting from the manufacturing process of Eco-Plank.
56
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Layered Corrugated Package Manufacturing
Facility-specific information was made available for the Menasha Sus-Rap Danville,
Virginia manufacturing facility. A questionnaire was completed by Menasha and a site visit was
conducted. Table 11 summarizes raw materials use, energy consumption, and waste generation
for the manufacturing operations based on equivalent use (protective packaging for one VCR). A
description of Menasha's manufacturing process for layered corrugated pads and a discussion of
the materials inventory is presented below.
TABLE 11 - INVENTORY OF INPUTS AND OUTPUTS FOR CORRUGATED
PAD MANUFACTURING
Category
Raw Material
Energy Requirements
Wastes
Input or Output
Layered Corrugated Pad
Starch-Based Aqueous Adhesive
Water-Based PVA Adhesive
Electrical
Natural Gas
Solid, Non-Hazardous Waste
Hazardous Waste
Wastewater
Air Emissions
Quantity
one unit
9.7 x ID'3 gal/unit (8.1 x 10'2 Ib/unit)
1.3 x 10'2 gal/unit (0.1 1 Ib/unit)
3.5 x 10-4 kW-hr/unit (1.2 BTU/unit)
2.6 x 10'2 SCF/unit (26.4 BTU/unit)
3.2xlO-2 Ib/unit
0
1.1 x 10'5 gal/unit (9.2 x 10'5 Ib/unit)
0
Menasha Sus-Rap manufactures three standard cushioning pad products: channel pads
("u"-shaped), angle pads ("v"-shaped), and flat pads (plank-type pads similar to those used as test
specimens in the technical evaluation of this project). One process line is devoted to the
production of channel pads, two process lines are devoted to the production of angle pads, and
one process line is devoted to the production of flat pads. One corrugation line supports all four
product process lines. The kraft paper used to manufacture the various pads is made of 100
percent post-consumer recycled material. Raw materials - paper and glues - are delivered by
tractor-trailer truck and stored on the process floor prior to use. Paper products are received hi
rolls; glues are received in 250 gallon totes.
The pad manufacturing process begins with the production of a single-sided corrugated
sheet, or single-facer - a flat sheet and a fluted sheet of paper bonded together. Two rolls of
paper are properly positioned and fed into the corrugation process unit. The corrugation process
unit then forms the flutes in one sheet, applies a water-based, starch adhesive between the sheets,
and presses the sheets together while applying steam to promote adhesion. Paper weights can
vary depending on the desired properties of the final product; typical paper weight is 26-pound
kraft paper. Paper width is also dependant on the final product.
The single-facer is then spooled into a roll for use in the flat pad or channel and angle
manufacturing processes. When spooled for channel and angle manufacturing processes, the
single-facer is first cut into four- to six-inch strips which run the length of the paper. Waste paper
trimmed from the sides of the single-facer during the cutting process is pneumatically conveyed to
a compactor where it is baled and sent off-site for recycling.
57
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Within the flat pad manufacturing process, any number of single-facer layers are combined
to create a pad that varies in thickness from 1/4 inch to 2 inches. From free-moving rolls, the
single-facer layers are pulled through glue application rollers where beads of water-based, vinyl
acetate adhesive are applied.. A conveyor system which pulls the layers through the glue
application system (and pushes the formed pad out) also compresses the layers to promote glue
adhesion and a consistent pad thickness. After compression, the pads are cut to standard length,
stacked, and stored for final processing.
A similar system is employed to combine the various single-facer layers to produce the
channel and angle pad products. Two to eight single-facer layers are typically combined using
beads of water-based, vinyl acetate adhesive. A conveyor system pulls the layers through the glue
application units, compresses the pads, and pushes the pads to the cutting station. The pads are
cut to length (typically three feet) either by a continuous guillotine-style cutter or a saw which
interrupts the movement of the pad. Each pad section is then folded into the channel or angle
shape. The pads are then stacked for final processing.
Final processing of the pads includes scoring, notching, or stamping. Scoring of a pad
allows customers to size the product as desired; notching and stamping allows the angle and
channel pads to bend around corners. Flat pads are cut to various sizes depending on customer
requirements. Other features that can be incorporated into the production process include the
following:
Single-facer layers can be scored every inch to allow customers to precisely size a
standard pad to a desired and specific size.
A fabric-lined single-facer layer can be included on the inside surface of the pads to
protect abrasion-sensitive product surfaces.
Printing on one outer surface of the pad is a recently added feature to Menasha's pad
products. Red or black print can be applied in simple designs (e.g., recycle symbols or
product identification numbers).
The various waste streams generated in Menasha's manufacturing facility include a solid,
non-hazardous waste and wastewater. The solid non-hazardous waste is primarily scrap paper
and formed corrugated products which is baled and returned to their kraft paper supplier for
reprocessing. Other solid wastes which may be generated, including bags, twine and rubbish, are
disposed of at a MS W landfill. The wastewater generated during the manufacturing process is a
result of purging and cleaning the glue lines of each assembly line. The water used for this
cleaning operation is collected in the empty glue totes and returned to the vendor for disposal or
reprocessing. The wastewater contains 85 percent water and 15 percent glue; equal quantities of
each glue (starch-based and poly vinyl acetate) are assumed to be present in the wastewater.
WASTE MANAGEMENT LIFE-CYCLE STAGES
Various waste management options are available for each of the cushioning materials
evaluated in this study, from reuse and recycling to composting. .Waste disposal options available
to each of the cushioning materials are presented in Table 12. Typical waste management
practices dispose of packaging material along with other MSW destined for landfill. The
58
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continual decline of available landfill space, however, was the primary cause for the public's
demand for more environmentally benign packaging.
TABLE 12 - POSSIBLE WASTE MANAGEMENT OPTIONS
EPS
Starch-Based Foam
Layered Corrugated
Recycled PE Foam
Landfill
Energy Recovery
Recycling
Composting
Water Dissolution
Figures for 1993 show that there are an estimated 207 million tons of MSW generated per
year in the United States. [54] That same year, the number of landfills accepting MSW was 4,482,
down from 8,000 in 1988. By 1994, the number of operating landfills had dropped to 3,558.[55]
Some closures were due to the more stringent standards for design, operation, and closure of
MSW landfills adopted by the U.S. EPA in 1991 .[56] Other landfills closed because they reached
capacity. While packaging wastes contribute to this landfill burden, there are more appropriate
waste management options that can be selected which would optimize both costs and
benefits. The following discussion presents selected options for each material, and evaluates the
potential national impacts resulting from them.
Expanded Polystyrene Waste Management Options
Polystyrene is a thermoplastic and is therefore 100 percent recyclable. The manufacturers,
raw material suppliers, and equipment manufacturers of polystyrene are trying to take advantage
of this fact, while reducing the burden of the nation's landfills. In 1989, the polystyrene industry
created the National Polystyrene Recycling Company (hereafter NPRC) which established four
major recycling centers. Since then, commercial recyclers have been establishing regional
recycling centers to serve both communities and businesses. [57] In July 1991, more than 80
companies, representing every major manufacturer of EPS protective foam packaging, joined
together to form the Association of Foam Packaging Recyclers (hereafter AFPR). Later that
same year, the AFPR and Polystyrene Loose-Fill Producers Council announced the formation of
programs for collection sites nationwide that are accepting shape-molded protective packaging
and loose-fill peanuts for re-use and recycling. Programs to recycle polystyrene now exist in over
25 states. [58].
The reuse and recycle of EPS foam can greatly reduce environmental burdens resulting
throughout the products life. -Using the same material multiple times in similar applications also
postpones its entry into a waste stream destined for landfill. Incorporating regrind into EPS
products can consume process waste that would typically enter the solid waste stream, while
reducing the-demand for PS resin. Also, reprocessing of EPS material can save nearly 80 percent
of the energy typically consumed to produce PE resin from virgin raw material sources (i.e.,
petrochemical feedstock).[59]
It is essential, however, that large quantities of EPS wastes are collected to make reuse
and recycling cost effective. This fact has been one hurdle which the associations and councils are
continually battling. The low density of EPS material limits its efficient transport over long
distances. To alleviate this potential problem, AFPR collection sites and associated facilities are
59
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located across the country. Nationally, few municipal recycling programs support the collection
of EPS; some do support the collection of crystalline polystyrene. From a life-cycle perspective,
the benefits gained by recycling and reusing EPS, as with any material, should be weighed against
the energy use and emissions resulting from its transport.
Starch-Based Foam Waste Management Options
Two waste management options most appropriate for starch-based foam take advantage
of their biological origin. The two options are composting and dissolution in water prior to
discharge, preferably to a POTW. Composting can take place in the consumer's back yard along
with yard trimmings and kitchen organic material, or take advantage of municipal compost
programs being established throughout the country. Dissolution of starch-based foam packaging
in water places an additional 'disposal' or treatment burden on local POTWs, but offers another
disposal option available to the consumer.
Municipal compost programs are being established across the country to offer an
alternative waste management option for organic material typically entering landfills. The vast
majority of this nation's programs focus on a single material, yard trimmings waste, while a small
fraction accept and manage mixed MSW. In 1994 there were 3,202 yard trimmings composting
facilities reported nationwide, [60] while only 17 MSW composting facilities were operating that
same year.[61] By March 1996, the number of yard trimmings compost facilities rose to over
4,000 and 22 additional MSW composting facilities were in various stages of planning, permitting,
construction, and pilot testing. [62] These figures and programs do not consider home/backyard
composting.
The dissolution of starch-based foam in water is the second option available to the
consumer for the disposal of this protective packaging. This disposal option would result in an
added biological oxygen demand (BOD) in municipal wastewater which typically enters a POTW.
The impact of this higher BOD is expected to be minimal for two reasons. First, the literature
BOD values for starch are around 0.75 Ib BOD per Ib starch. Even if large quantities of EcoPlank
are used in a particular packaging application, the dissolution of that material in water will
contribute insignificantly to local POTWs. Second, the distribution of protective packaging is
expected to be extensive enough to minimize the potential for concentrated applications of the
product. The relative insignificance of these impacts are supported by the "1992 Needs Survey
Report to Congress," completed by the U.S. EPA.[63]
Layered Corrugated Waste Management Options
Packaging recycling is gaining popularity as federal, state, and local initiatives continue to
support its growth. In the late 1980's, the U.S. EPA set national goals for MSW recycling. In
1994, the 24 percent rate of MSW recycling fell just short of the national goal of 25 percent. [64]
More' than 40 states have implemented similar goals and mandates. For example, the
Massachusetts legislature passed a bill mandating recycling and recycled content of specified
packaging rnaterials.[65,66] Industries and industry associations have also set goals and mandates
for recycling and recycled content packaging. Recycling is now available to more than 100
million United States citizens through curbside programs, drop-off centers, and buy back
centers. [67]
60
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Corrugated material is the highest recycled material, by weight, in the nation. [68]
Industry sources contribute most to the corrugated recycle stream - more than 60 percent of the
commercial sources of recycled corrugated material. Residential sources of corrugated material
to the recycle stream are extremely low - less than one percent. [69] However, the existing
national infrastructure for residential recycling offers the potential to expand current residential
corrugated recycling efforts.
"The 'success' of recycling schemes is usually judged in terms of the participation rate and
the quantity of material diverted from the waste stream. However, there is also a need for an
evaluation of the environmental and social impacts associated with the collection and transport of
recyclable materials."[70] No attempt was made, either in this study or the Tellus Packaging
Study previously mentioned, to assess, either quantitatively or qualitatively, the environmental
burdens associated with the collection and transport of recycled materials. As presented under the
recycling options of EPS, transportation can significantly reduce (possibly overshadow) the
environmental benefits of recycling. Transportation distances and the utilization of space in
collection vehicles are key factors that will influence the benefits and costs of recycling any
material.
Recycled PE Foam Waste Management Options
Based on the results of the technical evaluation, recycled PE foam exhibited characteristics
ideally suited for returnable/reusable packaging applications. The concept of reusable distribution
packaging is not new. Automobile manufacturers have demanded the use of returnable packaging
by then: suppliers. The application of reusable packaging in the consumer products industry,
however, has been limited. This limited application may be a result of a lack of information, an
infrastructure that would support a reusable packaging program, and/or product standardization.
National and international regulations concerning consumer product packaging, however, may
spur additional interest and information regarding returnable packaging.
If planned, organized and implemented properly, a returnable/reusable protective
packaging system can offer cost benefits and improve customer relations. Four features of
reusable packaging systems, presented in Table 13, have been identified. Also presented in Table
13 are some obstacles which limit the implementation of returnable/reusable packaging and
several options which could promote the implementation.
As presented in Table 13, short distances, frequent deliveries, small number of parties and
company-owned vehicles are the optimal features of an effective returnable/reusable packaging
system. Shorter distances mean lower return costs and a quicker return of containers to the
supplier. Frequent deliveries is closely tied to the rate which products are used/sold. If containers
are emptied quickly and frequent deliveries are required, storage space for empty containers is
minimized and the quantity of returnable containers in circulation is reduced. Controlling the
return of empty containers is easier when the number of parties handling containers is small.
Company-owned vehicles typically travel between a limited number of manufacturers/suppliers
and customers. Once a shipment is delivered, the dedicated line typically returns to the
manufacturer for another trip. This dedicated line thus simplified travel logistics and costs.
61
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TABLE 13 - FEATURES, OBSTACLES, AND PROMOTION OPTIONS FOR
RETURNABLE/RECYCLABLE PACKAGING SYSTEMS
Features
Obstacles
Promotion Options
Short distribution distances
Frequent deliveries
Small number of parties
Company-owned or "dedicated"
distribution vehicle
Large initial capital expense
Cost of tracking and accounting
for containers
Cost of returning containers to
point of origin
Lack of storage space for empty
containers
Resistance to change on the part
of suppliers, distributors, and
customers
Third-party leasing of containers
Company/Industry-wide
standardization
Cooperative efforts between
producers, suppliers, distributors,
and customers
Designing containers to be easily
stacked, stored, and reused
Government procurement
guidelines that favor reuse
Source: David Saphire. "Delivering the Goods-Benefits of Reusable Shipping Containers." INFORM, Inc.
1994.
CONCLUSIONS
The use or release of 33/50 toxic chemicals is not a direct result of either package
manufacturing or package use for the materials evaluated in this study. To assess the use and
release of 33/50 chemicals resulting from the use of each material, a life-cycle perspective was
taken for the environmental evaluation. With this perspective the use and release of 33/50
chemicals, along with other chemicals/releases of concern, was identified. Table 14 summarizes
these findings for each material for each of the three broad life-cycle stages evaluated: pre-
manufacturing, package manufacturing, and waste management.
The release of 33/50 chemicals was identified in the pre-manufacturing life-cycle stages for
all packaging materials. For the production of PS, benzene emissions to air and water
predominate all chemical releases to the environment. For the cultivation and processing of corn
to make the starch-based packaging materials, the use of 33/50 chemicals is limited to the
production of specific agricultural chemicals. Though agricultural chemicals are used throughout
the industry, the associated 33/50 chemical emissions is assumed to be minimal.
Insignificant 33/50 chemical releases are expected from the pre-manufacturing processing
steps required to produce recycled layered corrugated materials. Though zinc was identified as
the primary emission (i.e., emission factor) to water, this metal is assumed to be a contaminant of
the waste paper and has been significantly reduced in recent years with ink replacements. Finally,
the production of PE foam also required petroleum refining, resulting in the emission of benzene
to both air and water. The reported emission factor for chromium to water, however, was the
most significant 33/50 chemical release. Process energies are not reflected in these emissions.
62
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Within the facility-specific package manufacturing stage of each product's life cycle, the
most significant differences are energy consumption and the release of VOCs to air. The
manufacture of layered corrugated pads consume the least amount of energy and result in few
emissions to air or water. The release of the blowing agent pentane (a VOC to air) represents the
most significant environmental burden reported for the production of EPS packaging. Energy
requirements for the production of starch-based foam plank dominates the environmental profile
for this material within this life-cycle stage. Similar data for a PE foam package were not
available; PE foam manufacturers chose not to participate in the demonstration of their packaging
product in an electronic consumer product application.
Finally, various waste management options for each packaging material were evaluated.
Current land disposal of all packaging waste does not utilize characteristics inherent in the
material. EPS is a thermoplastic, and as such is readily recyclable. Tests have shown EPS
packaging, manufactured from recycled PS resin and renewed blowing agent, performs as well as
virgin EPS. A cost effective and efficient nationwide collection system, however, must be further
developed. The nature of starch-based foam plank makes it ideal for composting; dissolution in
water which then enters the POTW is also a viable option. Layered, corrugated pads can enter
existing recycle infrastructures across the country, and reuse/return options for PE foam will
utilize the superior cushioning characteristics of this material. Each option removes a burden
from the MSW stream and the landfill capacity of the nation. Each option also reduces the need
for virgin raw materials and thus reduces the resulting emissions.
This comparison of-environmental profiles has not considered the toxicity of the
pollutants/contaminants, nor their persistence in the environment and impact on human health and
the environment. For example, benzene is a proven human carcinogen, but degrades quickly in
the environment. The impacts of energy consumption and transportation requirements have also
been omitted from this evaluation. Transportation requirements may represent a significant
contributor to the environmental burdens when considering the collection requirements of
recycled materials. When considering the potential shift in environmental loadings between
selected materials, these issues must also be considered.
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CHAPTER 6
ECONOMIC EVALUATION
The cost of packaging is not merely the cost of materials and the expenses incurred
during the manufacturing process. Costs can also be measured in terms of package-product
assembly time, labor requirements, consumer values, distribution burdens, and more The
economic evaluation of this chapter attempts to address many of these cost parameters which
must be considered in packaging design, distribution, and sales. Quantitatively, the cost of
materials and manufacturing are assessed for EPS and each of the prototype designs. An
assessment of the additional cost parameters is accomplished qualitatively, identifying possible
benefits and burdens associated with each material and design.
Within identical packaging applications, assuming all other parameters are equivalent,
layered corrugated pads were the most cost competitive packaging alternative when compared to
EPS. Through 37 percent more expensive than EPS, layered corrugated pads were more cost
competitive than starch-based foam (which was over 400 percent more expensive than EPS).
Similar cost comparisons were not available for recycled PE foam.
MATERIALS AND MANUFACTURING
For many consumer-product manufacturers, the acquisition of packaging materials (in
their raw state) and the manufacture of desired cushioning configurations are accomplished
through contract manufacturers. Just as Tuscarora manufactures EPS protective packaging for
Philips, Menasha and American Excelsior satisfy the packaging demands of their customers.
Thus, the costs of materials and manufacturing are reflected in the purchase agreements
established between supplier and customer.
To compare the costs of the alternative packaging materials to those of EPS, price quotes
were requested from each packaging manufacturer. Two cost comparisons are presented below.
First, a cost comparison is presented for EPS end caps and the VCR prototype designs for starch-
based foam and layered corrugated pads, which were presented in the Technical Evaluation.
Secondly is a more general evaluation of the costs and benefits MAYTAG could experience if
their current packaging configuration for glass panels is replaced by the demonstrated prototype
designed by American Excelsior.
Comparison of Costs - Philips' VCR
American Excelsior and Menasha Sus-Rap were each asked to supply a cost quote for the
VCR prototype packaging design demonstrated above in the technical evaluation. Philips was
also asked to supply the cost of their current EPS packaging. The parameters used to establish
the cost estimates and a comparison of the cost quotes are discussed below for each material.
Expanded Polystyrene. Though manufactured and packaged elsewhere, Philips' cost for a set of
EPS end caps (i.e., a packaging unit) was estimated using the weight of the material (one set of
end caps), the end caps engineering shape, and the application of established conversion factors.
The conversion factors take into consideration the holes, indentions, and protrusions of the
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cushioning product, each of which contribute to the cost of the packaging system. From this
calculation, Philips' estimated cost for a set of end caps was $0.40 per unit. This price does not
reflect the cost of the corrugated box.
Starch-Based Foam. The cost for the starch-based foam prototype includes the quantity of
material consumed by the design, both starch-based foam and corrugated substrate, as well as the
labor costs associated with cutting and assembling the passing prototype design. The costs of the
EcoPlank prototype design was quoted at $2.35 per unit.
Layered Corrugated Pads. To estimate the cost of the layered corrugated prototype, Menasha
considered the thickness of the pad (i.e., number of layers), weight of paper used (e.g., 26 #
kraft), whether the design consists of flat pads, corner pads, or channel pads, as well as labor
requirements such as notching and assembly. The estimated prototype cost using this information
was calculated to be $0.57 per unit for 1,000 units and $0.55 per unit for 10,000 units.
Comparison of Costs - Philips' VCR. Each cost estimate presented above was completed in
isolation, with no direct knowledge of the competitor's price or the quantity of units desired. The
estimated costs for the layered corrugated prototype was the most cost competitive when
compared to the EPS packaging; the estimated price was 30 percent ($0.17) more per unit than
the current EPS system.
Starch-based foam is considerably more expensive; the unit price for the EcoPlank
prototype is six times the price estimated for EPS. It should be noted, however, that EcoPlank is
an emerging product, as EcoFoam loose-fill was six years ago. Tracking the cost per cubic foot
of EcoFoam loose-fill reveals a decrease of nearly 50 percent over the last six years. This cost
decrease can most likely be attributed to the establishment of a secure market, process
optimization, and economies of scale. A similar decrease in cost can be expected for EcoPlank as
the market becomes more established and American Excelsior takes advantage of economies of
scale. A 50 percent decrease would still place the price of EcoPlank above that of layered
corrugated and EPS. The benefits identified below may contribute to cost justifications.
Comparison of Costs - MAYTAG's Glass Panel
MAYTAG's current packaging configuration for the tested glass panel includes a
combination of plastic bubble wrap and crushed paper which surrounds the product in a
corrugated shipping box. The cost of this packaging design is $0.65 per package/product system
(includes box and protective materials). This cost is low when compared to that of the starch-
based prototype design which was estimated to be $4.80 per package/product system (includes
starch-based foam and box).
There are, however, additional costs associated with the current packaging design which
must be considered when comparing the two packaging systems. The current packaging
configuration for glass panels results in a ten percent damage rate of the product. Damaged
products cannot be repaired and must be replaced. This results in three additional costs. First,
the damaged panel must be properly disposed of; as MSW landfill tipping fees continue to
increase, this disposal cost becomes less significant. The second cost resulting from the damaged
shipment is that of the part itself. The glass panel tested in this project has a retail value of over
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$180. Finally, to replace the damaged part, a second part must be packaged M delivered
resulting in additional material costs and shipping fees. '
The starch-based prototype clearly showed effective protective properties durliig the
technical drop test series. If additional tests on the prototype design and current configuration
show superior protective properties offered by the prototype, the costs of panel replacement and
disposal would be eliminated. Such considerations must be assessed when alternative packaging
configurations/materials are considered to replace ineffective packaging systems.
ADDITIONAL COST PARAMETERS
There are a variety of general cost parameters which describe the options and issues that
must be considered for packaging design. These cost parameters include the following- capital
equipment costs, packaging line productivity, distribution costs (including the possibility of
returnable/reusable packaging), and consumer value. These costs are briefly discussed below.
Capital Equipment Costs
The capital equipment costs for the manufacture of packaging is strongly tied to the
packaging material selected. The use of molded EPS as a protective packaging material requires
the design and manufacture of new process molds each time the package design changes- rather
than change the manufacturing process equipment, the assembly requirements for layered
corrugated pads and starch-based foam changes as design configurations change. This difference
and the resulting costs may impact the selection of materials used for protective packaging.
Using the VCR EPS end caps as an example, the tooling costs to manufacture new molds
can range from $ 1,000 for a typical design, to $ 10,000 for the Teflonฎ-coated molds For
reasons of capital cost depreciation, these tooling costs are not typically included in the prices
quoted by packaging suppliers, and are not included in the cost estimate presented above for
Philips' end caps. Each time Philips changes a packaging design, mold tooling is an additional
cost that must be included in the overall packaging costs.
In contrast to this, both starch-based foam and layered corrugated pads, though limited in
title possible configurations, offer a diverse application base using the same process equipment
Flat and channel pads can be formed and combined in ways to accomplish a variety of design
configurations, even as the package and the product designs change. The costs of assembly labor
must be considered and is typically included in cost quotes from packaging suppliers. Starch-
based foam planks and layered corrugated pads may therefore offer more flexibility and save
money when considering capital investment requirements.
Packaging Line Productivity
Productivity is an issue concerning both the packaging supplier and the product
manufacturer responsible for assembling the product and package together into the distributed
product-package system. Productivity from the standpoint of the package manufacturer and the
product manufacturer is briefly discussed here.
To support product manufacturers, the package manufacturer must be able to supply a
continuous and consistent flow of protective packaging units. For example, a single product
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manufactured by Philips in Tennessee has a production rate as high as 1,500 units per shift. At
this time, neither Menasha Sus-Rap nor American Excelsior could support this production rate.
This, however, does not mean that given the opportunity, neither Menasha Sus-Rap nor American
Excelsior wouldn't expand current production to meet the new demand. Not all consumer
product manufacturers have such a high production rate. Other outlets for alternative packaging,
such as mail-order services, are also available. MAYTAG represents such an application of
alternative materials; multi-pack units are repacked individually and distributed to various
locations across the country. Economy of scale and productivity are expected to increase for
EcoPlank as the product becomes established in the market. Based on current packaging trends
(see Consumer Values below), layered corrugated pads, though used extensively in a variety of
furniture applications, may see increased application in consumer electronics resulting in greater
production capacities.
Packaging costs, beyond those of material costs, accrued by product manufacturers are a
result of materials management and product-packaging assembly processes. The packaging
design can influence both of these manufacturing packaging costs. Packaging systems that consist
of as few parts as necessary represent one way in which assembly costs can be minimized. Fewer
parts per product-package system simplifies packaging inventory requirement (i.e., materials
management). In addition, assembling fewer parts around a product simplifies labor burdens,
possibly shortening assembly tune and reducing labor costs. Another packaging design
consideration is that of 'ease of manipulation.' If a packaging system is easy to manipulate
around the product, the assembly system may be simplified and assembly time reduced.
Optimization such as this, of the product manufacturing process, can be observed in recent
modifications to the Philips' manufacturing process facility. Philips has automated portions of the
product-packaging assembly process to help optimize the entire manufacturing process. The
current protective packaging design (two end caps) works well with this automated system and
was a result of process optimization.
Distribution
Cube Efficiency. The issues of distribution costs were avoided in the VCR prototype designs by
placing the restriction of box size on the developed designs. As stated above, Philips has
optimized the volume available in all modes of transport (semi, rail, air); this optimization is
known as "cube efficiency." Stacked products consume as little space as possible, while balancing
the various sizes between products. By placing box size restrictions on the prototype designs, the
optimal use of space was not lost.
The size of the package-product system, however, must be considered when developing a
new packaging design for a product. If the package-product systems are distributed individually,
as in the case of MAYTAG, optimizing weight and material usage may influence cost more than
size. The costs associated with the distribution of multiple package-product systems, however,
can be greatly influenced by system size. Furthermore, the less-than-optimal use of transport
space may result in greater environmental burdens associated with increased transport
requirements.
Reusable/Returnable Packaging. A completely separate discussion of distribution costs is
required when product manufacturers and packaging designers consider returnable/reusable
packaging. The benefits and costs of reusable packaging are clearly presented in the INFORM
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publication, Delivering the Goods - Benefits of Reusable Shipping Containers.\11] Hypothetical
scenarios and actual case studies are presented in the publication. One hypothetical scenario
focuses on corrugated boxes, and shows the possible cost savings that could result from
packaging reuse:
A company that makes shipments in single-use corrugated boxes can cut the
quantity of container material needed for 1 million shipments by 50 percent if it
uses those boxes twice; by 70.6 percent if it ships its products in reusable boxes
that can be used five times; and by 98.5 percent if it switches from single-use
corrugated boxes to plastic containers that can be used 250 times.[72]
The use of returnable/reusable packaging incurs unique costs as well. These costs are
either the responsibility of the product manufacturer or the packaging designer, depending on who
is responsible for managing the returnable/reusable packaging. These unique costs include return
transportation to bring the returnable packaging back to a location where it can be reused, and
packaging inspection, maintenance, and reprocessing. Standardization of package and product
design can simplify the application of a reusable package, and make its application much more
cost effective. Packaging reuse is discussed further in the next chapter.
As previously mentioned, recycled polyethylene foam is suited for returnable/reusable
packaging applications; the dynamic behavior of PE foam offers protection even after multiple
drops with little deterioration of the material. Though a prototype design with recycled PE foam
was not developed for this study, costs savings from packaging reuse are included here for
completeness. Returnable/reusable packaging was discussed in the previous chapter,
Environmental Evaluation, when various waste disposal options were presented.
Consumer Values
In the field of industrial products, packaging serves the functions of containment,
protection in distribution, and identification. Most manufacturers consider the least cost'package
to be most appropriate, provided it performs adequately, regardless of what the competition is
doing. The consumer goods field is considerably more complex. The functions of containment
and protection are much like those for industrial packaging. Identification, however, must stress
brand names and product features, and provide purchase appeal.[73] Consumers respond to their
own perceptions of value; packaging designers must be aware of how consumers interpret
packaging and package changes. Consumer values supporting the environment are apparent from
the results of a number of public surveys.
"Consumers consider the 'garbage crisis' today's most important environmental issue and
see ecologically sound packaging, as a solution," according to a poll by a leading package-design
firm."[74] In this survey, consumers put solid waste ahead of air pollution as an area of concern
for the first time since 1989. Ninety-three percent of the consumers surveyed site buying
products in environmentally sound packaging as a solution to the solid-waste issue. [75]
However, in another survey conducted by the journal Packaging, consumer faith in package
recyclability as a means of lessening the trash burden is decreasing. [76] Experts in the packaging
field predict source reduction (using less packaging material) is the key to successful
packaging. [77] Consumer preference for recyclable, refillable/reusable, and recycled packaging
materials grew from 1993 figures; the growth in refillable/reusable packaging was the greatest at
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23 percent between 1993 and 1994. From the same survey, consumers believe consumer
electronic products and large household appliances use too much packaging. This opinion has
continued to increase from 37.7 percent in 1991 to 52 percent in 1994.
These consumer opinions can support the application of any of the cushioning materials
evaluated in this study if the materials are properly marketed. Many applications of EPS loose-fill
product packaging are accompanied by a letter to the consumer describing the recycle and reuse
programs available for used packaging. American Excelsior is establishing a similar informative
letter with EcoPlank packaging.
CONCLUSIONS
The costs associated with packaging extend beyond those of material costs. The
effectiveness of the packaging system, cubic efficiency, and consumer value can play important
roles when identifying cost effective packaging. The material costs were quantitatively assessed
in this study. When packaging the Philips' VCR, the prototype design for layered corrugated
pads was the most cost competitive when compared to EPS, while the starch-based prototype
design was nearly six times as much. MAYTAG's current packaging system, though inexpensive,
results in a damage rate that may represent a cost inefficient system. The starch-based foam
design, though expensive in comparison, may show positive performance (protective)
characteristics. These differences are summarized in Table 15.
TABLE 15 - COMPARISON OF MATERIAL COSTS
Packaging System
EPS
Bubble Wrap and Paper
Starch-Based Prototype
Layered Corrugated Prototype
Cost Per Packaging System
Philips' VCR
$0.40
NA
$2.35
$0.55
MAYTAG' s Glass Panel
NA
$0.65
$4.80
NA
NA: Not Applicable.
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CHAPTER?
CONCLUSIONS
This Cleaner Technology Demonstrations for 33/50 Chemicals project evaluated
alternatives to EPS as a cushioning material in. consumer and industrial packaging. EPS is an
example of the priority use cluster "plastics and resins," and is produced from raw materials
derived from the 33/50 chemical benzene. By demonstrating the technical, environmental, and
economic characteristics of alternative materials, it is hoped that alternative materials will replace
EPS in particular product packaging applications, thus reducing the emissions of benzene
resulting from EPS production and use.
Three 'alternative' cushioning materials were identified for evaluation within this research;
starch-based foam planks, layered corrugated pads, and recycled polyethylene foam. Though
some have been used as cushioning in packaging applications in the past, these materials are
termed 'alternative' because each offers unique features as well as adequate cushioning
capabilities. These unique features include their manufacture from recycled materials,
biodegradability, water solubility, recyclability, and reusability.
The goals of this project were to evaluate each packaging material in terms of
performance (technical evaluation), environmental impact, and economic efficiency. The results
of each evaluation are summarized below.
TECHNICAL EVALUATION
The results of the technical evaluation reveal the strengths and weaknesses of each
protective packaging material. While the results of dynamic tests were utilized in prototype
development, the applicability of static, stress-strain tests were not identified. Prototype
demonstrations using starch-based foam and layered corrugated pads show the ability of these
alternatives to replace EPS as a protective packaging material.
Under standard temperature and humidity conditions, dynamic drop test results
(summarized in Table 16) revealed positive cushioning characteristics of each material. Using
samples of 1.5 inches thick, layered corrugated pads offered as much protection as EPS for a
single drop; starch-based foam and recycled PE foam displayed lesser protective characteristics.
However, each displayed the ability to absorb multiple drops greater than that of EPS. High
temperatures and extremes in humidity seem to have the most significant impact of starch-based
foam, causing sample deterioration which resulted in decreased cushioning ability. Little change
in dynamic cushioning properties were identified for EPS, layered corrugated pads, and recycled
PE foam.
Test results from dynamic drops (i.e., cushioning curves) were used, in conjunction with
design expertise, to develop effective prototype protective packaging designs. EPS, while
adequately protecting a VCR from damage, did not perform to expected levels. Prototype
designs using layered corrugated pads and starch-based foam also protected the VCR from
damage, and performed to a level comparable to that of EPS. In applications which protect glass
products, starch-based foam prototype designs also revealed positive protective properties. These
results are presented in Table 17.
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TABLE 16 - SUMMARY OF OPTIMAL STATIC LOADS AND CORRESPONDING
G-FORCES FOR EACH MATERIAL
Material
EPS
Recycled PE Foam
HD Starch-Based Plank
LD Layered Corrugated
Optimal Static Load
(Ib/sq inch)
0.82
0.37
0.64
0.52
G-force
51
55
72
46
Key: HD = High Density
LD = Low Density
Note: Drop Height = 30 inches; Sample Thickness = 1.5 inches
TABLE 17 - SUMMARY OF PROTOTYPE DESIGN RESULTS
EPS (current)
Bubble Wrap and Paper (current)
Layered Corrugated Pads (prototype)
Starch-Based Foam Plank (prototype)
VCR Packaging
Passing
NA
Passing
Passing
Glass Panel Packaging
NA
10% damage rate
NA
Passing
NA: Not Applicable; a design using this material was not tested.
ENVIRONMENTAL EVALUATION
The purpose of the environmental evaluation was to assess the various and unique
environmental loadings resulting from the life cycle of each packaging material, from raw material
extraction to processing and waste disposal. A shift in environmental burdens would occur if an
alternative packaging material was used to replace EPS in consumer product packaging
applications. The environmental burdens for EPS would be reduced if another material was used,
while the environmental burdens resulting from the manufacture of an alternative material would
possibly increase due to increased demand. Table 18 summarizes the pollutants which result from
the life cycle of EPS, starch-based foam plank, and layered corrugated pads. Due to the lack of a
prototype design, limited data was available for recycled PE foam, and thus is omitted from this
summary.
This study was implemented to show potential reductions in the use and release ot me
33/50 chemical benzene resulting from the manufacture and use of EPS. The environmental
loadings presented for pre-manufacruring.show reductions of benzene releases are possible if EPS
were replaced by an alternative material. Facility-specific information indicates that releases of
pentane would decrease, while energy consumption has the potential to increase or decrease,
depending on the alternative material selected. Waste disposal options available for each material
show potential benefits and depend on the waste management option selected regardless of
material.
72
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The use of an alternative packaging material, however, will result in its own unique
environmental burdens. For starch-based foam, the pre-manufacturing processes of agricultural
chemical production, crop production, and corn processing must be considered. Though the
release of benzene is not expected, other 33/50 chemicals may be emitted, primarily in agricultural
chemical manufacturing processes. For example, for the production of atrazine, a pesticide
commonly applied to corn, the 33/50 chemical hydrogen cyanide is used. The package
manufacturing life-cycle stage consumes significantly more energy than the EPS package
manufacturing process, and waste disposal options must consider the potential impact on
wastewater treatment facilities if the starch-based packaging material was dissolved and washed
down the drain.
The use of layered corrugated pads as a replacement for EPS also results in unique
loadings to the environment. Pre-manufacturing data indicate few, if any 33/50 chemical
emissions to air or water, however, other environmental loadings are expected. The manufacture
of layered corrugated pads consumes the least energy of any packaging alternative, and is
expected to result in no additional environmental loadings to air or water. Finally, the potential to
recycle corrugated materials in existing infrastructures offers a benefit above EPS.
The comparison of environmental loadings did not consider the toxicity of the
pollutants/contaminants, nor their persistence in the environment, potential exposure to humans,
and impact on human health and the environment. The impacts of energy consumption, such as
global warming, have not been addressed either. When considering the potential shift in
environmental loadings between selected materials, these issues must also be considered.
However, from the information presented in this evaluation, layered corrugated pads seem to
represent a better packaging material on environmental merits.
ECONOMIC EVALUATION
The costs associated with packaging extend beyond those of material costs. The
effectiveness of the packaging system, cubic efficiency, and consumer value can play important
roles when identifying cost effective packaging. The material costs were quantitatively assessed
in this study. When packaging the Philips' VCR, the prototype design for layered corrugated
pads was the most cost competitive when compared to EPS, while the starch-based prototype
design was nearly six tunes as much. MAYTAG's current packaging system, though inexpensive,
results hi a damage rate that may represent a cost inefficient system. The starch-based foam
design, though expensive in comparison, may show positive performance (protective)
characteristics. These differences are summarized in Table 19.
TABLE 19 - COMPARISON OF MATERIAL COSTS
Packaging System
EPS
Bubble Wrap and Paper
Starch-Based Prototype
Layered Corrugated Prototype
Cost Per Packaging System
Philips' VCR
$0.40
NA
$2.35
$0.55
MAYTAG's Glass Panel
NA
$0.65
$4.80
NA
NA: Not Applicable.
74
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RECOMMENDATIONS
The results of this study show the potential application of alternative packaging materials
to replace current uses of EPS. Potential environmental benefits and the economic
competitiveness of selected materials offer further support for the use of these alternative
materials. There is, however, more information that must be made available to packagers and
manufacturers to support the use of the alternative materials. This information, identified as
future research topics, includes the following:
The technical evaluation assessed each material at a single thickness over a finite set of
static loads. It is the opinion of this research team that further tests be conducted to more
accurately define the dynamic cushioning curves over a wide range of material
thicknesses.
The creep tests completed in this study were terse and qualitative. To support the use of
alternative materials, boundaries for the characteristics of creep (or set) must be
established.
A greater understanding of the effects environmental conditions (e.g., temperature and
humidity) have on the materials and their performance capabilities is suggested.
Finally, all packaging designers must divorce themselves from the practice of filling void
space when packaging consumer products. The cushioning characteristics of the
alternative materials must be properly utilized, and materials use must be optimized to
offer a competitive price for the alternative materials.
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80
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APPENDICES
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APPENDIX A
TRIAXIAL PIEZORESISTIVE ACCELEROMETER
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ENDEVCOฎ MODEL 7267A
TRIAXIAL PlEZORESISTiVE ACCELEROMETER
Replaceable Elements
The ENDEVCO Model 7267A is a reclaceable-element triaxial accelerometer designed to measure acceleration in tt-.njฐ
mutually perpendicular axes. Although designed for installation in the heads of anthropomorphic test cummies usec in
automotive crash studies, it has acolication wherever triaxial accelerometers are used for steady state or long duration pu'se
measurements. The Model 7267A uses ENDEVCO's PIEZITE* jjiezoresistive elements in half-bridge configuration.
The three sensors are mutually perpendicular and are positioned so their sensitive axes pass throucn the centers of sei^ic
mass and intersect at a single point.
Each sensor is replaceable. It is held in place by a single screw for easy installation cr removal by the user. Sclder pins sre
provided for electrical connection of an easily replaced nine-conductor cable. Both side and top cable entry holes are creviced
Accessories include a TO ft (3.05 m) cacie and a mounting base. Sensors, housing and caole clamp are available as reciacerr=nt
components.
(All values are typical at +75ฐ F l~24"C] unless otherwise specified.)
PERFORMANCE
RANGE
SENSITIVITY
(at 10 Vdc excitation, ref 100 Hz)
Typical/Minimum
NON-LINEARITY & HYSTERESIS
(% of reading, max, to full range)
FREQUENCY RESPONSE
(ฑ5% max, ref 100 Hz)
MOUNTED RESONANT FREQ'
DAMPING RATIO
TRANSVERSE SENSITIVITY (max)
THERMAL SENSITIVITY SHIFT
(ref+75-F[+24ฐC])
ZERO MEASURAND OUTPUT (max)
THERMAL ZERO SHIFT (max)2
g
mV/g
%
Hz
Hz
%
%
ฐF
c
mV
mV
ฑ1500
0.15/0.10
ฑ1 (ฑ2% max at 1500 g)
0 to 2000
12 000 Hz
0.005
3
ฑ3
-10/+150
-23/+S6
ฑ25
ฑ15
ELECTRICAL
EXCTTATION14
INPUT RESISTANCE"
INSULATION RESISTANCE
(minimum at 100 Vdc)
GROUNDING
Vdc
n
MO
10.0
1000
100, pin to case
Cable shield common to
WHGHT (excluding cabte)
CASE MATERIAL
ELECTRICAL CONNECTIONS4
MOUNTING/TORQUE
ACCELERATION LIMITS
(in any direction)
Static
Sinusoidal
Shock
TEMPERATURE
Operating
Non-Operating
HUMIDITY
Isolated from sensor pins
PHYSICAL
oz(gm) 1.76(50)
Corrosion-resistant steel
Integral nine-conductor
shielded cable
Two holes for 4-40 mounting
screws.
6 lbf-
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APPENDIX B
STEP-BY-STEP PROCEDURES FOR LABORATORY TESTS
Dynamic Drop Tests
Static Compression Tests
Creep Tests
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The procedures followed in this study are presented step-by-step in Figures Bl, B2, and B3.
Further details, as defined by ASTM Standard Method D 1598 - 91, follow the figures.
FIGURE Bl - STEP-BY-STEP DYNAMIC DROP TEST PROCEDURE
Calibration
Periodically, transducers are returned to the manufacturer for re-calibration. The procedure described below is
followed in the interim, and represents Philips' standard operating practices.
Step #1 Secure two identical transducers together using double-sided adhesive tape;
2 Drop the transducer pair and record dynamic acceleration-time histories for each transducer; and
3 Compare each read-out; if peak G-force readings for each transducer are within 5 to 10 percent of each
other, each transducer is considered calibrated.
Preparation of Apparatus
Step #1 Mount desired load to static load platen;
2 With double-sided tape, mount transducer to the top surface of the static load platen;
3 Connect compressed air source to pneumatic suction platen; and
4 Set desired parameters within the Setup menu of the computerized data acquisition system.
Preparation of Sample
Step #1 Measure and record the thickness of material samples (see details);
2 Measure and record the area of material samples (see details);
3 Measure and record the mass of material samples (see details); and
4 Mount a single material sample on apparatus platform with double-sided tape.
Dynamic Tests
Step #1 Lower pneumatic suction platen onto static-load platen;
2 Open compressed air valve to initiate suction;
3 Using the winch, begin to raise platens to the desired drop height (see details);
4 Position platform, with mounted sample, under the static-load platen;
5 Using a tape measure, position static load such that the distance from the top of the sample material to
the bottom of the mounted static load equals that of the desired drop height (see details);
6 Close compressed air value allowing the static-load platen to drop freely onto material sample;
7 Save resulting dynamic drop test curve as single, retrievable file;
8 Ready the computerized data acquisition system by clearing operating memory;
9 Repeat Dynamic Test Steps #1 through #9 to generate a series of five dynamic drop test curves for a
single material sample; and
10 From single event drop test curves record peak G-force.
B-l
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FIGURE B2 - STEP-BY-STEP STATIC STRESS-STRAIN TEST PROCEDURE
Preparation of Apparatus
Step # 1 Mount compression cell onto top crosshead of Instron;
2 Record gear configuration;
3 Mount and adjust paper chart and recording pen; and
4 Record chart speed and range.
Prcpareation of Sample
Step # 1 Cut samples to desired size with razor blade;
2 Measure and record the thickness of material samples (see details);
3 Measure and record the area of material samples (see details); and
4 Mount a single material sample on platform of lower crosshead.
Dynamic Tests
Step #1 Engage Instron motor, raising lower crosshead until sample touches lower surface of compressometer,
then disengage motor;
2 Turn on pen and chart switches;
3 Engage motor again, recording displacement and time parameters as the sample is compressed;
4 Disengage motor and turn off pen and chart switches when sample has been compressed to 50 percent
original thickness; and
5 Transpose time-displacement data into stress-strain data.
FIGURE B3 - STEP-BY-STEP CREEP TEST PROCEDURE
Preparation of Apparatus
Step #1 Condition environmental chamber to 50 ฐC; and
2 Determine required weight and moment arm length to impose proper loads to each sample.
Preparation of Sample
Step #1 Measure and record the area of material samples (see details); and
2 Position samples under moment arms within environmental chamber.
Dynamic Tests
Step #1 Load moment arms with weight; and
2 Record the change in specimen thickness after one, two, five, ten, fifteen, and twenty minutes;
record the change in specimen thickness after one, two, five, ten, and fifteen hours; record the
change in specimen thickness after one, two, five, and seven days; for the remainder of the test
measure the change of specimen thickness once per week.
Details for Measuring Thickness. A sample thickness of 1.5 inch was selected prior to test
initiation, based on industry partner requirements. Material manufacturers were asked to submit
cushioning material samples of this thickness. Following the ASTM methodology, on each test
day the thickness of each material sample was measured and recorded. Using a calipers equipped
with calibrations able to measure to the nearest thousands of an inch (0.001 in.), four
measurements of thickness were recorded for each sample, one at each sample edge. The
thickness of the sample is then reported as the average of these four measurements.
B-2
-------
Details for Measuring Area. The area of each material samples was dictated by the apparatus
used during test series. The sample platform and falling static load platen restricted a sample area
during the dynamic drop tests to the dimensions of 6 x 6-inch square; 4 x 4-inch square samples
were used during stress-strain tests, consistent with the area offered by the crosshead platform;
sample sizes for the creep tests were 4 x 4-inch square for starch-based foam plank, 3 x 3-inch
square for recycled polyethylene foam, and 3 x 4-inch rectangular of layered corrugated and EPS,
each offering the appropriate load for the test. Samples from each material manufacturer were
obtained in 6 x 6-inch square pieces; required sample sizes were cut from these samples using a
razor blade. For each sample, a total of four measurements were recorded; two measurements for
length and two measurements for width. Measurements were made to the nearest 1/32-inch using
an engineering ruler. The area was then determined by averaging each pair of measurements and
then multiplying the averages together, as expressed in Figure B4.
FIGURE B4 - SAMPLE SCHEMATIC AND AREA MEASUREMENTS
Wl
t
thickness
width
= sample
Area = (Wl + W2)/2 x (LI + L2)/2
Details for Measuring Mass. The mass of each sample was measured and recorded using an
Acculab battery-operated pocket scale (Pocket Pro 250-B). This scale is able to display mass in
units of grams (as well as ounces and troy ounces), with a readability to the nearest tenth of a
gram (0.1 g, or 0.01 oz, or 0.01 ozt.) and a maximum mass of 250 grams. The mass of each
sample was measured and recorded in. grams.
Additional information regarding test parameters and collected data include the following:
The range of static loads for the dynamic drop tests was established by using a
combination of stainless steel plates which offered six standard weights, from 8 to 33
pounds in 5-pound increments.
Temperature and relative humidity of the storage room (an office at the Center for Clean
Products) in which the samples were dept were measured and recorded daily during the
series of dynamic drop tests.
B-3
-------
Static loads for the creep tests were set at five percent of the final strain established by the
static stress-strain tests. This level of strain resulted hi the following loads per area for
each material: EPS, 8.7 lb/ sq in; starch-based foam, 0.3 Ib/sq in; recycled PE foam, 2.2
Ib/sq in; and layered corrugated pads, 4.3 Ib/sq in.
B-4
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APPENDIX C
EXAMPLE OF QUESTIONNAIRE TO ASSESS FACILITY-SPECIFIC
ENVIRONMENTAL LOADING
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ENVIRONMENTAL DATA QUESTIONNAIRE
The University of Tennessee Center for Clean Products and Clean Technologies is
conducting research to evaluate the performance, cost, and environmental aspects of cushioning
materials. Funded through a cooperative agreement with the U.S. Environmental Protection
Agency, this project will evaluate the technical (i.e., performance), economic, and environmental
aspects of the alternative cushioning materials in comparison to expanded polystyrene (EPS).
Technical evaluations within the laboratory have been initiated for all cushioning materials. This
questionnaire is intended to initiate the environmental evaluations by gathering needed data
regarding environmental aspects of EPS foam manufacturing and materials use. With this
questionnaire it is not the Center's intention to reveal proprietary information or trade secrets.
The requested data, however, are required to evaluate all aspects of the process as it relates to the
environment. Please respond to the following data requests as completely as possible.
Raw Materials
The information gathered in this section is intended to identify ALL materials
incorporated into your standard EPS foam product. Please specify the following information
regarding all materials that are used in its manufacture. This information will be used as the
primary source of data for the assessment of life-cycle environmental aspects of all raw
materials. Therefore, please be as specific as possible.
Polystyrene
resin/bead vendor/supplier
resin/bead density as received
blowing agent (please specify)
blowing agent/resin ratio (e.g., mass agent/mass resin)
. (please specify units)
Does resin contain some recycle resin content? (check response) Q yes Q no
percent recycle content please specify units, by vol. OR by wt.)
source of recycled material
Other Materials
Please identify any other materials used or incorporated into your standard EPS foams
(e.g., mold release).
Material Foam's Content (% by vol./wO
Please attach applicable MSDSheets.
C-l
-------
Energy Requirements
The energy requirements to manufacture EPS foam is also required to assess the total
environmental impacts of the products under investigation. While manufacturing your foam
products, what are the energy requirements for each process unit (or the entire manufacturing
process as a whole)? If actual energy consumption figures are known, please offer that
information in the following section; otherwise, complete the capacity, duty, and load
information as presented (see note, below). For a comparison with other production processes
and products under investigation, it would be ideal if this information would be presented on a
per-unit-of-production basis. If this in not possible or practical, please present information on a
single, common basis (e.g., average manufacturing day).
Energy Consumption of Entire Production System
OR
Resin Delivery Unit:
Actual Energy Consumption
OR
Nameplate Capacity
Duty
Load
. (please specify units)
. (please specify units)
Steam Generator:
Actual Energy Consumption
OR
Nameplate Capacity
Duty
Load
. (please specify units)
Pollution Control Unit (please specify):
Actual Energy Consumption
OR
Nameplate Capacity
Duty
Load
. (please specify units)
Other (please specify):
Actual Energy Consumption
OR
Nameplate Capacity
Duty
Load
. (please specify units)
C-2
-------
Other (please specify):
. (please specify units)
Actual Energy Consumption
OR
Nameplate Capacity .
Duty
Load
Note: Duty is defined here as the percentage of time a process unit is operated; for example 6
hours out of an eight-hour day, or 75 percent duty. Load is defined here as the percentage of the
unit's capacity which is being utilized; for example, a pump that has a nameplate capacity of 60
gal./min. but is operating at 45 gal./min. represents a load of 75 percent.
Waste Streams and Clean-Up
An assessment of the wastes generated during the manufacture of EPS foams will be
accomplished utilizing the data gathered below. Please present generation rates for each of the
waste streams identified below as average values based on overall production. For conversion
and comparison with other products, the overall production rate is also requested.
Overall Production Rate
, (please specify units)
Do you generate non-hazardous wastes?
If yes, please specify the following:
rate of generation
composition
Q
yes
Q
no
. (please specify units)
method of disposal.
What type(s) of recycling is being conducted within this manufacturing facility? Are the
quantities of recycled materials included in the figure identified above for the non-
hazardous waste stream?
Do you generate process wastewater?
If yes, please specify the following:
average flow rate
yes
Q
no
average composition.
pretreatment Q yes
. (please specify units)
. (please specify units)
Q no
C-3
-------
If yes, please specify the following:
Q required Q voluntary
describe treatment train
Please attach pertinent permits.
Q
yes
Do you generate process air emissions?
If yes, please specify the following:
Q controlled Q uncontrolled
If controlled, please specify control technologies.
Please specify composition/constituents
Q
no
Please attach pertinent permits.
Do you generate hazardous wastes? Q
If yes, please specify the following:
rate of generation
composition
yes
no
. (please specify units)
disposal method.
C-4
U.S. QOVEKUENT PRINTUM OFFICE: 1998-65D-001X80191
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