Plastics Recycling
Technical Assistance Report
PLASTICS RECYCLING
TECHNICAL
ASSISTANCE REPORT
FINAL
REPORT
Prepared for:
CWC
A division of the Pacific NorthWest Economic Region
(PNWER)
9992200 Third AvenueAlaskan Way, Suite 10460
Seattle, WA 9810421
March 1999
Project
consultants:
Cascadia Consulting
Group
O'Brien & Company
DAK Consulting
LBA Associates
This recycled paper is recyclable
Copyright © 1999 CWC. All rights reserved.
Federal
copyright laws prohibit reproduction, in whole or in part, in any printed,
mechanical, electronic, film or other distribution and storage media, without
the written consent of the CWC. To
write or call for permission: CWC, 999 2200 Third AvenueAlaskan Way, Suite 10460, Seattle, Washington 9810421, (206) 4643-707406.
Disclaimer
CWC disclaims all
warranties to this report, including mechanics, data contained within and all
other aspects, whether expressed or implied, without limitation on warranties
of merchantability, fitness for a particular purpose, functionality, data
integrity, or accuracy of results. This
report was designed for a wide range of commercial, industrial and
institutional facilities and a range of complexity and levels of data input. Carefully review the results of this report
prior to using them as the basis for decisions or investments.
Report No. PL-99-1
ACKNOWLEDGMENTS
CWC is a nonprofit
organization providing recycling market development services to both businesses
and governments, including tools and technologies to help manufacturers use
recycled materials. CWC is an affiliate
of the national Manufacturing Extension Partnership (MEP) – a program of the US
Commerce Department’s National Institute of Standards and Technology. The MEP is a growing nationwide network of
extension services to help smaller US manufacturers improve their performance
and become more competitive. CWC also
acknowledges support from the US Environmental Protection Agency and other
organizations.
Recycled Plastic
Products, Inc., and Plastics Design and Manufacturing (PDM) were selected for
this technical assistance project.
Recycled Plastic Products, Inc., manufacturers and distributes a line of
recycled plastic fencing products, and PDM is a custom molder, which provides molding services to
Recycled Plastic Products. CWC would also like to
thank the
contract molding facility, Techworks (located in Denver, CO)
TABLE OF CONTENTS
Page
EXECUTIVE SUMMARY…………………………………………………………………...1
1.0 PLASTICS RECYCLING
TECHNICAL ASSISTANCE REPORTS……….….…..4
1.1
Extension
Molding Technical Assistance Project……………………….…….4
1.2
Injection Molding Technical Assistance
Project……………………….……...9
2.0
REPORT
ON EXTRUSION MOLDING TESTS………………………….…………14
2.1
Procedure………………………………………………………………….…….15
2.2
Observations………………………………………………………………….…16
2.3
Recommendations and
Conclusions……………………………….…………..17
2.4
Content Process
Optimization for Converting to Recycled Content….….....19
2.4.1 Material Considerations…………………………………………..…....19
2.4.2
Extruder Hardware
Considerations…………………………….…….20
3.0
REPORT
ON SECOND EXTRUSION MOLDING TESTING………………….....23
3.1
Procedure……………………………………………………………………….24
3.2
Observations……………………………………………………………………25
3.3
Recommendations and
Conclusions…………………………………………..26
3.4
Equipment Suppliers…………………………………………………………..27
4.0
REPORT
ON INJECTION MOLD TECHNICAL ASSISTANCE PROJECT…...30
4.1
Procedure……………………………………………………………………….30
4.2
Observations………………………………………………………………….…31
4.3
Recommendations and
Conclusions…………………………………………...31
5.0
REPORT
FROM TECHWORKS ON PHYSICAL TESTING RESULTS………....33
5.1
Process and Test Criteria…………………………………………………..….33
5.2
Procedure……………………………………………………………………….34
5.3
Observations……………………………………………………………...…….35
5.4
Recommendations and
Conclusions…………………………………………..36
..
APPENDICES
APPENDIX
A: Evaluation Reports: Summary of Plastic Molders/Results of Interviews
APPENDIX
B: Plastics Project Selection Criteria &
Evaluation
APPENDIX
C: Molders Survey Interview Forms
APPENDIX
D: Material Test Results
EXECUTIVE
SUMMARY
The goals of this
project were
to provide
hands-on technical assistance to selected Colorado businesses and to
demonstrate the effectiveness of recycling extension services to those businesses. Two separate technical assistance projects relating
to plastics recycling were undertaken as part of the Industrial Partnership
Program (IPP): 1) using recycled plastic flake in an
extrusion molding process; and 2) using recycled plastics in an injection
molding process. This report presents
the results and
evaluation of
these efforts.
The first project
provided support to a manufacturer in using recycled plastic flake as a
substitute for pellets, with the aim of helping to develop and expand the
potential market for locally produced clean-washed HDPE flake; most, if not all
manufacturers in Colorado are currently only manufacturing with pellets.
The product and process
for the technical assistance project was a hollow profile extrusion for 1"
x 6" and 1" x 8" fence pickets.
The extrusion process used an extruder with a water-filled vacuum tank and
a pulley. The product was originally
manufactured with 100% reclaimed HDPE pellets (Dupont™), with a color and
ultraviolet (UV) inhibitor additive.
Testing was performed
on two different dates at a custom molder's extrusion molding department. Materials selected for testing included
Talco's™ 100% post-consumer HDPE washed flake, and EcoPlast's™ 100%
post-consumer HDPE washed flake. It was
determined that both products were the same in quality and composition, and
therefore, only the Talco product was used for testing purposes.
On the first testing
date, samples of 20%, 40%, 60%, and 80% flakes, mixed with the Dupont pellets,
were prepared and extruded, both with and without the color additive. The extrusion process and processing parameters
were monitored, samples of the extruded pickets were taken for each sample mix,
and the quality of each sample mix was observed. The test samples were collected and sent to a testing lab to
perform physical property testing. Based on
preliminary test results, a second testing with samples of 25%, 30%, and 35%
flake mixed with Dupont pellets was requested to better determine the upper
threshold of flake content.
Test results indicated
that a blend of 25% flake provided a product of acceptable physical and visual
quality, and the mix of flakes and pellets could be processed on the existing
equipment without any modifications in equipment or process parameters. Additional equipment is required to mix the
flakes and pellets at a higher ratio.
This project demonstrated
the economic and technical feasibility of using recycled plastic flake in a
minority ratio with pellets in a specific extrusion molding process. This
increased usage could provide a new market for recycled plastic bottles in
Colorado, create new jobs in recycling and processing the flake, and offer a
superior cost alternative to more distant national markets for recycled plastic
bottles.
The other technical
assistance project consisted of two elements:
(1) testing the use of recycled plastic in an injection molding process;
and (2) conducting a survey of injection molding companies in Colorado about
recycling issues.
The testing involved
using both injection grade plastics and bottle grade recycled plastics, with
the aim of helping to develop and expand the potential market for locally
produced, recycled-injection grade plastics.
The testing included processing trials of the recycled plastics in an
injection molding process and laboratory testing of the recycled-content parts, to determine their
strength and melt flow characteristics.
The survey consisted of
questions aimed at identifying the market potential and requirements for using
recycled injection grade plastics in existing injection molding manufacturing.
The process testing was
conducted at a contract molding facility, Techworks (located in Denver, CO), on
a total of 13 samples, including recycled bottle grade high density
polyethylene (HDPE) flake from two different suppliers, mixed with injection
grade virgin HDPE pellets. The feedstock
mixes were tested at 20% flake, 40% flake, 60% flake, and 100% flake.
Processing tests were
also conducted on several injection grade plastics samples, including
repelletized post-consumer HDPE, repelletized post-industrial polypropylene
(PP), post-consumer dairy tub containers in flake form [(mixed HDPE and LDPE
(low density polyethylene)], post-consumer HDPE buckets and crates in flake
form, and post-industrial PP in flake form.
All sample materials were processed in a commercial scale injection-molding
machine, using a non-proprietary mold as a testing mold. All material samples were also sent to a
testing laboratory for tensile strength, melt index and impact strength
testing.
Information provided by
the facility indicated that all of the bottle grade HDPE mixes processed
adequately with similar processing conditions and times. Both of the repelletized samples (HDPE and
PP) also processed sufficiently.
Processing results of the remaining samples (with flake from dairy tubs,
buckets, crates, and post-industrial PP) were unsuccessful, apparently due to
various contaminants in the samples.
The test results
indicated that the physical properties of the plastics were within usable ranges
for the resin types, and comparable with their virgin resin equivalents. However, significant variation was seen
between the recycled HDPE flakes provided by two different suppliers, although
both samples were supposedly from post-consumer HDPE bottles. Additional testing of multiple samples over
time would be required to determine the variability from suppliers of the
recycled plastics tested in this project.
Table of Contents
Extrusion Molding Technical Assistance Project 23
Goals 23
Selection Criteria 23
Activities 23
Outcomes 34
Injection Molding Technical Assistance Project 56
Goals 56
Selection Criteria 56
Activities 56
Outcomes 67
Detailed Report on Extrusion Molding Tests 89
Plastics Extrusion Molding Technical Assistance Project: Report
from TechWorks on the First Extrusion Molding Testing, 8/3/98 89
Procedure 910
Observations 1011
Recommendations and Conclusions 1112
Process Optimization Considerations for Converting
to Recycled Content 1213
Report from TechWorks on Second Extrusion Molding
Testing 1415
Procedure 1516
Observations 1617
Recommendations and Conclusions 1718
Equipment Suppliers List 1819
Detailed Report on Injection Mold Technical
Assistance Project 2021
Report from TechWorks 2021
Procedure 2122
Observations 2122
Recommendations and Conclusions 2122
Report from TechWorks
on Physical Testing Results 2324
Process and Test Criteria 2324
Procedure 2425
Recommendations and Conclusions 2526
Evaluation
Report: Summary of Survey of Colorado Based Plastic Molders 2627
Evaluation Report: Results of Interviews with
Extrusion Plastics Company Personnel 2930
Interview with Gene Pendery, President Recycled Plastic Products Inc. 2930
Interview with Al Chavez, PDM 3031
AttachmentA: Plastics Project Selection Criteria
& Evaluation 3132
Attachment B: Molders Survey Interview Forms 3435
Attachment C: Material Test Results 3536
1.0 Appendix 3: PlPlasti
Appendix
3:
Plastics
Recycling Technical Assistance Report & Evaluation 2
Extrusion Molding Technical Assistance Project 2
Goals 2
Selection Criteria 2
Activities 2
Outcomes 3
Injection Molding Technical Assistance Project 5
Goals 5
Selection Criteria 5
Activities 5
Outcomes 6
Detailed Report on Extrusion Molding Tests 8
Plastics Extrusion Molding Technical Assistance
Project: Report from TechWorks on the First Extrusion Molding Testing, 8/3/98 8
Procedure 9
Observations 10
Recommendations and Conclusions 11
Process Optimization Considerations for Converting
to Recycled Content 12
Report from TechWorks
on Second Extrusion Molding Testing 14
Procedure 15
Observations 16
Recommendations and Conclusions 17
Equipment Suppliers List 18
Detailed Report on Injection Mold Technical
Assistance Project 20
Report from TechWorks 20
Procedure 21
Observations 21
Recommendations and Conclusions 21
Report from TechWorks on Physical Testing Results 23
Process and Test Criteria 23
Procedure 24
Recommendations and Conclusions 25
Evaluation Report: Summary of Survey of Colorado
Based Plastic Molders 26
Evaluation Report: Results of Interviews with
Extrusion Plastics Company Personnel 29
Interview with Gene Pendery, President Recycled
Plastic Products Inc. 29
Interview with Al Chavez, PDM 30
AttachmentA: Plastics Project Selection Criteria & Evaluation 31
Attachment B: Molders Survey Interview Forms 34
Attachment C: Material Test Results 35
Appendix 3:Plastics
Recycling Technical Assistance
Report & Evaluation 3
Extrusion Molding Technical
Assistance Project 3
Goals 3
Selection criteria 3
Activities 3
Outcomes 4
Injection Molding Technical
assistance Project 6
Goals 6
Selection criteria 6
Activities 6
Outcomes 7
detailed report on
extrusion molding tests 9
Plastics Extrusion Molding
Technical Assistance Project: Report from TechWorks on the first extrusion
molding testing, 8/3/98
