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
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Copyright © 1999 CWC. All rights reserved.
Federal
copyright laws prohibit reproduction, in whole or in part, in any printed,
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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 9
Procedure 10
Observations 11
Recommendations and
conclusions 12
Process Optimization
Considerations for Converting to Recycled Content 13
Report from TechWorks on
Second Extrusion Molding Testing 15
Procedure 16
Observations 17
Recommendations and
conclusions 18
Equipment Suppliers List 19
Detailed Report on
Injection Mold Technical Assistance Project 21
Report from TechWorks 21
Procedure 22
Observations 22
Recommendations and
conclusions 22
Report from TechWorks on
Physical Testing Results 24
Process and Test Criteria 24
Procedure 25
Recommendations and
Conclusions 26
Evaluation Report: Summary
of Survey of Colorado based Plastic Molders 27
Evaluation Report: Results
of Interviews with
Extrusion Plastics Company Personnel 30
Interview with Gene
Pendery, President Recycled Plastic Products Inc. 30
Interview with Al Chavez,
PDM 31
AttachmentA: Plastics Project
Selection Criteria & Evaluation 32
Project Overview: 32
PROJECT ASSESSMENT AND
RATINGS: 33
Feasibility within time and
scope of IPP project 1 33
Reasonable probability of
success 1 33
Ability to institutionalize
use of recycled materials 2 33
Immediate implementation
possibilities 2 33
Ability of technical
assistance to close market gap- solve problem 2 33
Transferability of lessons
learned to other businesses 2 33
Visibility of company and
project- value for support
and funding 2 33
Volume of material utilized 2 33
High market impact - value
of material utilization 3 34
OTHER PROJECTS CONSIDERED: 34
Attachment B: Molders
Survey Interview Forms 35
Attachment C: Material Test
Results 36
Appendix
3: 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 9
Procedure 10
Observations 11
Recommendations and conclusions 12
Process Optimization Considerations for Converting
to Recycled Content 13
Report from TechWorks on Second Extrusion Molding
Testing 15
Procedure 16
Observations 17
Recommendations and conclusions 18
Equipment Suppliers List 19
Detailed Report on Injection Mold Technical
Assistance Project 21
Report from TechWorks 21
Procedure 22
Observations 22
Recommendations and conclusions 22
Report from TechWorks on Physical Testing Results 24
Process and Test Criteria 24
Procedure 25
Recommendations and Conclusions 26
Evaluation Report: Summary of Survey of Colorado
based Plastic Molders 27
Evaluation Report: Results of Interviews with Extrusion
Plastics Company Personnel 30
Interview with Gene Pendery, President Recycled
Plastic Products Inc. 30
Interview with Al Chavez, PDM 31
AttachmentA:
Plastics Project Selection Criteria & Evaluation 32
Project Overview: 32
PROJECT ASSESSMENT AND RATINGS: 33
Feasibility within time and scope of IPP project
1 33
Reasonable probability of success 1 33
Ability to institutionalize use of recycled
materials 2 33
Immediate implementation possibilities 2 33
Ability of technical assistance to close market
gap- solve problem 2 33
Transferability of lessons learned to other
businesses 2 33
Visibility of company and project- value for support and funding
2 33
Volume of material utilized 2 33
High market impact - value of material utilization 3 34
OTHER PROJECTS CONSIDERED: 34
Attachment B: Molders Survey Interview Forms 35
Attachment C: Material Test Results 36
Appendix 3:
PlasExtrusion Molding Technical
Assistance Project 2
Goals 2
Selection Criteria 2
Activities 3
Outcomes 4
Injection Molding Technical
Assistance Project 5
Goals 5
Selection Criteria 5
Activities 6
Outcomes 6
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 9
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 15
Procedure 16
Observations 17
Recommendations and
Conclusions 18
Equipment Suppliers List 19
Detailed Report on
Injection Mold Technical
Assistance Project 21
Report from TechWorks 21
Procedure 21
Observations 22
Recommendations and
Conclusions 22
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
Project Overview: 31
PROJECT ASSESSMENT AND
RATINGS: 32
Feasibility within time and
scope of IPP project 1 32
Reasonable probability of
success 1 32
Ability to institutionalize use of
recycled materials 2 32
Immediate implementation
possibilities 2 32
Ability of technical
assistance to close market gap- solve problem 2 32
Transferability of lessons
learned to other businesses 2 32
Visibility of company and
project- value for support and funding 2 32
Volume of material utilized 2 32
High market impact - value
of material utilization 3 33
OTHER PROJECTS CONSIDERED: 33
Attachment B: Molders
Survey Interview Forms 34
Attachment C: Material Test Results 35
tics Recycling Technical
Assistance REPORTS & EVALUATION
Report & Evaluation
Introduction
Two separate technical
assistance initiatives relating to plastics recycling were undertaken as part
of the Industrial Partnership Project (IPP):
1) using recycled plastic flake in an extrusion molding process; and 2) testing
the viability of using recycled plastics in an extrusion injection molding
process. This appendix presents
the results of these efforts as well as the evaluation undertaken by the
consultant team.
1.1
Extrusion Molding Technical Assistance Project
GoalsGoals
The goals of the
technical assistance portions of the IPP project arewere to provide
hands-on technical assistance to selectedselect Colorado
businesses and to demonstrate the effectiveness of providing recycling
extension services to Colorado businesses.
Selection Criteria
Selection criteriaSelection Criteria
TThe IPP project solicitation specified that one of the three technical
assistance projects should be addressed to a a plastics manufacturer
converting to recycled materials or using more recycled materials in their
product. Using this as a guideline, a
plastics focus group comprised of plastics manufacturers, suppliers and processors in Colorado
was formed. Input was gathered by the group and asked for input on the most appropriate and effective areas for
technical assistance in the local plastics industry. Other
In addition to the criteria was added, including that
the project select a plastics manufacturer converting to recycled materials or
using more recycled materials in their product, other criteria were added,
including an achievable scope, budget
and schedule within the project constraints,
and a technical assistance area of focus that would have benefits for plastics
recycling in the sState.
The focus group
suggested and reviewed several possible technical assistance projects, and
finally recommended a project focusing on the plastics manufacturing use of
recycled HDPE or LDPE in a washed flake form. These resins have some
established collection and handling infrastructure already, providing a
potential supply of locally generated materials. The project team had already identified several manufacturing
companies who used
recycled pellet imported from outside of Colorado.
of the State.
A processing system to grind and wash these materials could
potentially be economically effective in competition with out-of-state
pelletizing operations. The technical
assistance project would provide assistance to a selected manufacturer in using
recycled flake as a substitute for pellets, with the aim of helping to develop
and expand the potential market for locally produced clean washed HDPE or LDPE flake. The processing equipment required to feed
flakes could be different than that for pellets, and most if not all
manufacturers in Colorado are currently only operating with pellets.
Activities
Based on the
recommendations of the plastic focus group, the technical assistance project
was designed with the following components:
1. Survey
potential manufacturing markets for recycled materials and develop
needs/requirements, focusing on HDPE and LDPE, and noting all potential
opportunities to use washed flake in substitution for pellets.
2. Create
a material testing model to provide samples of washed flake to a selected
manufacturer to develop, test, and demonstrate the requirements for using
recycled materials in their manufacturing process. A range of usable specification properties
could be developed and then tested to validate the specifications.
3. Provide
technical assistance on feed equipment requirements, and operating
procedures for using the flake material, and evaluatinge the
cost-effectiveness of appropriate equipment modifications for the use of flake
instead of or in addition to pellets.
Recycled Plastic
Products, Inc.,
and Plastics Design and Manufacturing (PDM) were selected for the technical
assistance project. Recycled Plastic
Products manufactures and distributes a line of recycled plastic fencing
products, and PDM Plastics
Design and Manufacturing is a custom molder, which provided ing the
molding services to Recycled Plastic Products.
The product and process for the technical assistance project was a
hollow profile extrusion for 1”
byX 6” and 1” byX 8”
fence pickets. The extrusion process
used an extruder with a water-filled vacuum tank and a pulley.
The
product is manufactured with Dupont 100% reclaimed HDPE pellets, with a color
and UV inhibitor additive.
Testing was done on
two different dates at PDM’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. Based on comparisons
of the two testing materials, it was determined that they were essentially the
same in quality and composition. , and
Ttherefore,
only one material, the Talco product, was used for testing purposes. On the first testing date, July
6, 1998, 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 the
preliminary results of the first tests, Recycled Plastic Products requested a
second testing with samples of 25%, 30% and 35% flakes mixed with the Dupont
pellets, to better determine the upper threshold of flake content. This second testing was conducted at PDM on
October 6, 1998, and followed ing the
same procedures as the first testing date.
A telephone survey was
developed by the project team and conducted by TechWork. The survey consisted of s, contacting
extrusion molders and asking a series of questions regarding the current and
potential use of recycled resins in their manufacturing processes, and the
potential for the use of clean flake as a substitute for pellets.
Outcomes
During the first
testing date, it appeared that at 20%, the processing system performed near normal,
(material had to be hand blended), with no problems with the feed system,
extrusion operation, maintaining integrity of profile through vacuum tanks,
cooling process, and puller and chop saw. The product quality was generally acceptable
and comparable to the standard product with DuPont pellets. There was We did see some
contamination from labels or foreign plastic in all product samples, and some
color contamination from foreign plastic in natural-colored samples.
The 40% blend
presented problems with process stability.
There were no problems with the feed system but the extruder
required constant adjustment to maintain part integrity in the vacuum tanks and
water bath. The increased flake and
foreign particles caused voids in the product, resulting in holes in the product.
With the 60% blend, a stable product could not be achieved even
with we continued feeding of the material. the material but were
not able to achieve a stable product. The
extruder was able to melt and blend the material but caused the die to clog and
the product could not be pulled through the we
were not able to pull the product through the water bath vacuum
tank. After several attempts to
stabilize the process, there was no success in we were unsuccessful in
getting product through the process.
During the second testing
date, it appeared that at 25%, the processing system performed near
normal, as with the 20% level. The
product had to be will
have to be examined by the customer, who was to
to determine
whether the quality would
be will be acceptable and comparable to
the standard product with 100% DuPont pellets.
We continued to see There was still some
minimal contamination from labels or foreign plastic in all product, and color
contamination from foreign plastic in natural-colored samples.
During the 30% and 35%
mix tests, the processing system performed near normal, with no problems with
the feed system, extrusion operation, cooling process, puller and chop
saw. The integrity of profile coming
out of the die seemed a little more flimsy but no adjustments were made. There was We did see significantly
more contamination from labels or foreign plastic causing sink marks, and it was which
we would assumed that this would cause the product to be
rejected. Color contamination from
foreign plastic in natural-colored samples continued.
The customer did not has
yet to examine the product run in this test, but it would seem and of course has
the final say in the quality of his product but it would seem from
the reresults of the above test, that a blend at
25% would still provide a product of acceptable visual quality. While higher percentage mixes were
able tocould
be processed adequately, visual defects at levels above 25% would most likely
be unacceptable. For extrusion products
with lower aesthetic requirements, products not extruded using a vacuum tank in
the process , and/or
solid profile products, these factors would not be limiting and higher
percentage mixes of flake , up to
40% and higher could be processed.
Also, based on the custom molder’s experience, the use of larger
diameter extruders at lower RPM and processing temperature could reduce
problems with off-gassing from recycled material, improve processing of flake
mixes, and
allow mixes of approximately 50%.
Based on the results
of the processing tests, the mix of flakes and pellets could be processed on
the existing equipment without any modifications in equipment or process
parameters. Some additional equipment
would be required to mix the flakes and pellets at the desired ratio. This could be done on a batch basis,
producing gaylord quantities of the mix for feeding with the existing feed and
process equipment. The best process and
equipment for this mixing function may be the topic of additional testing
and/or technical assistance for this processor, and the costs of this
additional equipment would have to be weighed against the economic benefits of
using the flake material.
The economic benefits
of using recycled flake at a 25% ratio are substantial. At current pricing, including transportation
of the flake material from out of state, the flake could provide a $0.05 to
$0.10 per pound discount from pellets, including transportation costs to
PDM. While this discount could vary,
depending on pricing fluctuations, at 25% of all feed material, and a typical
processing volume of 80,000 pounds per month, the use of flake could save
$1,000 to $2,000 per month in materials costs. These savings, or the discount of flake from pellets could be
even greater if the flakes were locally produced, assuming that locally
prepared materials would have a reduced transportation cost. From a local market development standpoint,
this manufacturer, using clean flake at the suggested levels, could create a
demand for up to 240,000 pounds per year for locally produced clean washed
flake.
Results from the The molders
survey results indicates d that
there could be an might
be additional market potential for use of clean flake. Of the 25 companies for which survey results
were completed, roughly one- third used HDPE in
injection or extrusion molding and about the same percentage used washed flake or
clean industrial regrind on a regular basis.
Most of these used clean industrial regrind from their own
in-house scrap materials. The major
concerns with the use of flake from outside sources were consistency of
materials, quality of materials and supply of materials. A little less than half of the respondents indicated that they would
use technical assistance program services in using new materials such as recycled
clean flake in their manufacturing operations.
1.2. Injection Molding Technical Assistance Project njection Molding Technical assistance Assistance Project
Goals
The goals of the
technical assistance portions of the IPP project were are to
provide hands-on technical assistance to selected Colorado businesses and to
demonstrate the effectiveness of providing recycling extension services to those Colorado
businesses.
Selection Criteria
This is the second
technical assistance project dealing with plastics manufacturing, and was
included in the project after a technical assistance project focusing on
recycled glass materials was not available.
As with the first plastics project, in addition to the criteria that the
project select a plastics manufacturer converting to recycled materials or use ing more
recycled materials in their product, other criteria were added, including an
achievable scope, budget and schedule within the project constraints, and a technical
assistance area of focus that would have benefits for plastics recycling in Colorado. the State.
The plastics focus group had
suggested a secondary project, dealing with a market survey and technical
assistance for the use of post- consumer
injection grade HDPE, LDPE , and PP. These resins and packaging types (diary tubs, buckets, crates,
etc.) have very limited collection and handling infrastructure in Colorado. There have been some existing regional
markets for this material, although these have dwindled in
recent months, and a relatively large number and capacity of
injection molders in the state. Technical assistance focusing on this
group of resins could help to open- up
collection, processing and re-manufacturing for materials currently not being
recovered.
Activities
Based on the
recommendations of the plastic focus group, the technical assistance project
was designed with the following components:
1. Survey
potential manufacturing markets for recycled materials and develop needs/requirements,
focusing on injection grade HDPE, LDPE and PP.
2. Provide
samples of recycled injection grade materials to a selected virgin manufacturer
to test and demonstrate the requirements for using recycled materials in their
manufacturing processes, and provide technical assistance on feed equipment
requirements, and operating procedures for using the recycled material.
Sample testing and
processing using available molds was performed at TechWorks’ facility.
Processing tests were
conducted on a total of 13 samples, including mixes of recycled bottle grade
HDPE (high density polyethylene) flakes from two suppliers with injection grade
virgin HDPE pellets, at 20% flakes, 40% flakes, 60% flakes and 100%
flakes. Processing tests were also
conducted on several injection grade plastics samples, including repelletized
post-consumer HDPE, repelletized post-industrial PP (polypropylene),
post-consumer dairy tub containers in flake form (mixed HDPE and LDPE-low
density polyethylene), post-consumer buckets and crates in flake form (HDPE),
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.
Outcomes
Anecdotal information
provided by the facility indicateds 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 adequately.
Processing results of
the remaining samples were unsuccessful, apparently due to various contaminants
in the samples. The post-consumer dairy tub containers
in flake form (mixed HDPE and LDPE-low density polyethylene) was were extremely
runny with a viscosity similar to water.
The processor was unable to maintain it in the barrel and it immediately
clogged the mold, which required a complete teardown and clean out of the machine. The processor did not clarify if this was a
problem with the sample material or inappropriate settings on the
injection-molding machine. This sample
was not re-tested.
No processing results
were provided for the post-consumer buckets and crates in flake form (HDPE).
The post-industrial PP
in flake form could not be processed successfully, due to water contamination
in the sample. This sample was dried, still had contaminants and clogged the
nozzles.
The physical testing
results for the HDPE flake and virgin pellet mixes showed increasing tensile
strength and impact strength, along with decreasing melt flow , as
the percentage of recycled flakes was increased. This was because the flakes were from bottle-grade HDPE, which
typically has a higher strength and lower, or fractional melt flow value
compared to injection grade HDPE. The
following table shows typical ranges of melt flow rate, tensile strength and
Izod Impact values for different grades of HDPE.
|
Grade HDPE
|
Density, g/cc
|
Melt Flow Rate #g/10 min.
|
Tensile Strength at
Yield, 1000 psi
|
Izod Impact, Notched
ft-lb/in (1/8 in)
|
|
Blow Molding Grades
|
.945
- .961
|
0.05
– 100
|
3.3
– 4.4
|
1.4
– 2.2
|
|
Extrusion Grades
|
.941
- .961
|
0.1
– 54
|
2.4
– 3.5
|
8
– 16
|
|
Injection Grades
|
.942
- .964
|
0.2
– 100
|
2.3
– 4.8
|
1.2
– 1.8
|
Because the HDPE
material blends followed a fairly consistent pattern of increasing strength and
decreasing melt flow with increasing percentage of bottle-grade flake, the
tests do iindicated that a predictable strength and melt flow
could be obtained from a mix of the recycled bottle-grade flakes and injection
grade virgin pellets. Thus, , allowing
a manufacturer to use the flakes to prepare a feedstock with desired
characteristics for a specific application.
The repelletized
post-consumer HDPE showed strength test results comparable to that of the
post-consumer flake, and a noticeably higher melt flow value. The repelletized post-industrial PP showed
low strength for PP resin, and a melt flow similar to the HDPE flake
materials. The post-consumer dairy tub
containers in flake form (mixed HDPE and LDPE-low density polyethylene) was not
tested due to significant contamination of the sample in the form of glass,
aluminum and other metal. The
post-consumer buckets and crates in flake form (HDPE) tested a
low
strength value, and the post-industrial PP in flake form tested within the
expected range for strength and melt flow.
The test results
indicated
that the physical properties of the materials tested are within usable ranges
for the resin types, and comparable with their virgin resin equivalents. The remaining issue for successful use of
these types of materials would be the consistency of supply. Typically, recycled plastics can vary
significantly from batch to batch, both in strength, melt flow and color,
causing processing and quality problems for manufacturers. 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 of the specific supplies of recycled
plastics tested in this project. The
following table presents the results of the testing.
|
Sample Material
|
Melt Flow Rate #g/10 min.
|
Tensile Strength at Yield, 1000 psi
|
Izod Impact, Notched ft-lb/in (1/8 in)
|
|
(1)
HDPE Talco flake 20%, 80%
virgin
|
13.190
|
2.970
|
0.63972
|
|
(2)
HDPE Talco flake 40%, 60%
virgin
|
6.440
|
3.210
|
0.92156
|
|
(3)
HDPE Talco flake 60%, 40%
virgin
|
5.608
|
3.290
|
0.64486
|
|
(4)
HDPE Talco flake 100%, 0% virgin
|
0.740
|
3.635
|
4.7203
|
|
(5)
HDPE EcoPl flake 20%, 80% virgin
|
8.744
|
3.240
|
0.64486
|
|
(6)
HDPE EcoPl flake 40%, 60% virgin
|
5.608
|
3.285
|
1.1241
|
|
(7)
HDPE EcoPl flake 60%, 40% virgin
|
4.816
|
3.315
|
1.8171
|
|
(8)
HDPE EcoPl flake 100%, 0% virgin
|
0.862
|
3.555
|
4.61526
|
|
(9)
PP CPR PP scrap
|
20.932
|
4.085
|
0.39482
|
|
(10)
Mix CPR dairy tub scrap
|
No
test results
|
No
test results
|
No
test results
|
|
(11)
HDPE CPR bucket and crate scrap
|
12.610
|
2.090
|
0.28916
|
|
(12)
HDPE EcoPl repro pellets
|
6.928
|
3.815
|
0.76068
|
|
(13)
PP EcoPl repro pellets
|
8.962
|
2.325
|
1.3898
|
Results from the The telephone
survey results indicated that there is thed
that
there is a potential for a
substantial substantial potential market for
recycled plastics in the existing plastics manufacturing community in
Colorado. Twenty-one injection molders
and four extrusion molders responded to the survey. Of the respondents, 27% used HDPE and 31% used PP (some may used both). Approximately 30% of the respondents
used washed
flake or industrial regrind on a regular basis, although most appear
to used
regrind from their own operations. A
substantial majority A majority has has uused recycled
plastics in the past, with a wide range of results, from very negative
experiences to no problems. About
one-third of the respondents
stated that they said
they would consider using a technical
assistance program, and the needs included help with obtaining a reliable
supply of consistent materials, technical information on the properties and
procedures for using recycled materials, and assistance in finding markets for
internally-generated regrind materials.
Some applications, such as medical products and regulated or certified
products,
would not be able to use recycled materials, but many
other applications exist which could potentially use some recycled
materials.
With a number of
plastic injection molding companies located in Colorado, there is the potential
for a significant increase in the use of locally generated and produced recycled
plastic flake material. This increased
usage could provide a new market for recycled plastics in Colorado, create new
jobs in recycling and processing the plastics, and offer a superior cost
alternative to more distant national markets for recycled plastic materials.
2.0 DETAILED REPORT
ON EXTRUSION MOLDING TESTS detailed report on
extrusion molding testsDetailed Report on Extrusion
Molding Tests
A report on the first extrusion molding testing relating to the plastics extrusion
molding technical assistance project was prepared by TechWorks. on the
first extrusion molding testing. Plastics Extrusion
Molding Technical Assistance Project: Report from TechWorks on the first
First
extrusion Extrusion molding
Molding
testingTesting,
8/3/98
Recycled Plastic Products,
Inc., and Plastics Design Manufacturing (PDM) were selected for this technical project. Recycled Plastic Products, Inc.,
manufactures and distributes a line of recycled plastic fencing products, and
PDM is a custom extrusion company located in Denver, Colorado, and provides molding
services to Recycled Plastic Products.
This study was performed on a plastic fence line.
Equipment: 2 ½”, 24:1 Akron Extruder
High
Compression Screw
2
station Maguire Proportional Loader
Note: There was no screen on the extruder to catch
contaminants. Also other equipment in line included 2 or 3 vacuum tanks with
“plate molds”?, ”, a puller and a chop saw.
Product: 1” x 6” board of lumber,
060-070 thick.
Material: Dupont’s Tyvek Reprocessed
Pellet, Natural
Talco’s
washed HPDE flake.
When we arrived, tThe machine
was running 100% reprocessed Tyvek pellets and was . Machine was running good
product. The settings were as follows:
RPM: 83
(actual) 125 (max)
AMP: 49
PSI (head): 700
Melt Temperature: 405
Barrel Temp Settings:
Zone
1 (rear) 370
Zone
2 360
Zone
3 371
Zone
4 380
Zone
5 (Nozzle) 349
Zone
6 (Die) 335
2.1 Procedure
Procedure
Although there was a 2two- station
proportional loader on the machine, the material was hand- blended
because of the flake. Blenders are
available that will handle flake and should be considered if the project progressed. moves forward. Blends of 20%, 40%, 60% and 80%
flake- to -pellet were
prepared.
The 20% blended
natural material was added to the process.
This
material was run for ten minutes and consistent product was
achieved. We We ran this material for
10 minutes and got consistent product. We then added Wwhite
color concentrate was
added at a 2½% letdown ratio. The
process was stable and the following was observed: we
observed the following:
20%
Natural 20% w/color
RPM: 83.2 82.7
AMP: 48.2 45
PSI (head): 700 700
Barrel Temp Settings:
Zone 2 360 361
Zone 3 370 369
Zone 4 382 381
Zone 5
(Nozzle) 348 351
Zone 6 (Die) 335 335
|
|
20% Natural
|
20% w/color
|
|
RPM:
|
83.2
|
82.7
|
|
AMP:
|
48.2
|
45
|
|
PSI (head)
|
700
|
700
|
|
Melt Temperature
|
400
|
398
|
|
Barrel Temp Settings:
|
|
|
Zone
1 (rear)
|
369
|
369
|
|
Zone
2
|
360
|
361
|
|
Zone
3
|
370
|
369
|
|
Zone
4
|
382
|
381
|
|
Zone
5 (Nozzle)
|
348
|
351
|
|
Zone
6 (Die)
|
335
|
335
|
There was evidence of
labels and some non-melted pellets. Parts
continued to be acceptable to the customer although the contaminants were
evident.
After 15 minutes of
running this material, we switched
over to the 40% blended material was run.
The following
observations were made:
We observed the
following:
40%
Natural 40% w/color
RPM: 83.1 83.3
AMP: 45.8-46.3 45.7
PSI (head): 700 700
Melt
Temperature: 398 396
Barrel Temp
Settings:
Zone 1
(rear) 369 364
Zone 2 361 355
Zone 3 370 365
Zone 4 384 362
Zone 5
(Nozzle) 349 350
Zone 6 (Die) 335 335
The following observations were made:
|
|
40% Natural
|
40% w/color
|
|
RPM:
|
83.1
|
83.3
|
|
AMP:
|
45.8-46.3
|
45.7
|
|
PSI (head)
|
700
|
700
|
|
Melt Temperature
|
398
|
396
|
|
Barrel Temp Settings:
|
|
|
Zone
1 (rear)
|
369
|
364
|
|
Zone
2
|
361
|
355
|
|
Zone
3
|
370
|
365
|
|
Zone
4
|
384
|
362
|
|
Zone
5 (Nozzle)
|
349
|
350
|
|
Zone
6 (Die)
|
335
|
335
|
To raise the amperage
draw, t
The temperatures were
We lowered
the
temperatures by 5% across -the- board. to raise the amperage draw. The
product was witnessing sink marks and there was it was difficulty we
were having trouble holdinging the
profile. The speed was We increased
the
speed when the temperature stabilized; . tThe RPM’s
returned to 83. Although the process
stabilized, the parts were unacceptable because we were blowing holes
were being
blown in the profile where the labels and contaminants were.
Next, tWe
introduced the he 60% blend was introduced. We lost sStability of the
process was lost
and the temperatures and screw speed had to be raised to achieve a seal. and had to raise all
temperatures and screw speed to achieve a seal. The RPM’s were 105 and then lowered to 96. The die clogged and the process could not
be held. we could not hold the
process.
Observations2.2 Observations
·
The product was acceptable at a 20% blend, but
did not meet specification at 40%..
·
Contaminants were evident but did not effect the
product at 20%.
·
The flake ranged in size from .300 - .700. In a random 1 cup sample, we
found contaminants were found to consist of the following:
Approximately 7,000 –
8,000 parts
Contaminants 53 parts
Labels – 21 parts
Plastic – 32 parts
This
representsed approximately ½% foreign particles present
in the material. The plastic
contaminants appeared
to be other mixed bottles and plastic caps.
The labels included paper, plastic and printed plastic.
·
In addition to poor product characteristics, the
process was unstable and unable to run under normal operating procedures.
·
Product Quality
0% Flake – In a 14
linear inch sample the
following was we found:
0 non-melts
1 black spec
no color contamination
20% Natural Flake – In
a 15 linear inch product sample the we observed the following was observed:
3 non-melts
7 color disbursements over a 4 ½”
section of product
Good product stability
20% Flake with White
color
2 non-melts
2 contaminants
1 black spec
40% Natural Flake
1 non-melt
9 contaminants
2 black specs
Poor product quality
40% Flake with color
2 non-melts
6 contaminants
Poor product quality
Recommendations and
conclusionsRecommendations and Conclusions 2.32 Recommendations
and Conclusions Observations
It appeared that at
20%, the
processing system performed near normall,
(material had to be hand- blended), with no problems with the feed
system, extrusion operation, maintaining integrity of profile through vacuum
tanks, cooling process and puller and chop saw. Product quality was generally acceptable and comparable to the
standard product with DuPont pellets. There was some We did see
some contamination in all product from from labels
or foreign plastic,
in all product, and
color contamination from foreign plastic in natural-colored samples.
The 40% blend
presented problems with process stability.
There were no problems with the feed system but the extruder
required constant adjustment to maintain part integrity in the vacuum tanks and
water bath. The increased flake and
foreign particles caused voids in the product, resulting in holes in the product.
With the 60% blend, a stable product was
not achieved even with we continued feeding of the material. but were not able to achieve a stable
product. The extruder was
able to melt and blend the material, but caused the die to clog and we
it wasn't possible
to were not able to pull the product
through the water bath. After several
attempts to stabilize the process, there was no success in getting the we
were unsuccessful in getting pproduct through the process.
Due to the marginal
success of the 40% blend and the lack of success with the 60% blend, there was no attempt we
did not attempt to run the 80% and 100% blends of material.
Additional studies may
be conducted to find the upper limits between the range of 20%and 40%. This would will aid in finding allow
us to find tthe maximum level of recycled- content
allowed by the product.
Screw configuration or
a static mixer may assist with the non-melts that were found in the product. Additional mixing of the material would will eliminate
resins that did not have time to melt under normal processing conditions. This could will assist
in removing them from the product.
Accurate metering of the flake in the process would will offer
stability in the process by insuring precise amounts of material blended. This metering device would be most effective
if placed on the throat of the extruder and material introduced directly on the
screw. If the material is metered at a
separated station and pneumatically conveyed to the machine, consideration
should be given to the type of pneumatic conveying that is done. Due to the difference in bulk density of the
flake and pellet, separation could occur during the conveying process. The equipment supplier would ill be
able to assist in the evaluation of equipment purchased. Smaller consistent
flake size could prove beneficial. With
a more consistent material, the screw would be able to mix is able to mix the
material better in the transition and mixing section of the screw and will
help would
aid in stabilizing stabilize the process. A screen pack
with an automatic screen changer may help remove labels in the extrusion
process.
Process Optimization
Considerations for Converting to
Recycled Content2.4 Content Process
Optimization Considerations for Converting to Recycled Content 0
Processes are unique
to the material, product, equipment and even the processor. Although there are no hard set
rules, the following guidelines will increase
the chance of success for the introduction of recycled material.
2.43.1 Material
Considerations
·
Resins and additives that are to be used with
the recycled material need to be compatible.
It is recommended that the material be a similar polymer base with like
processing parameters.
·
Drying recycled material will can
make it easier to process. When
possible, it is we recorecommended that the material be
dryed, drying the material even when it is
not typically hygroscopic.
·
The thermal history of the material is an
important aspect of processing. It is
important to know if the material was sourced from a virgin product (indicating
one heat history) or if the source of the product had recycled content in it
(indicating multiple heat histories).
With shear sensitive materials, this becomes is even more
important. If the material experiencesd
excessive heats during the initial processing, it will be more difficult to
feed and will impact how the material processes.
·
Mixing efficiency of the material is important
and should be considered when choosing the type of recycled material to be
used. If the material is difficult to
mix, a special screw design could be required.
·
Equipment and environmental cleanliness is
another important aspect for successful implementation of this program. The material should be kept covered and free
of contaminants. It is important to
understand the cleanliness policies of the material supplier as well.
·
Pellet/flake geometry will impact how well the
material feeds and runs. When doing a
visual inspection of the material, it is important to note the size and shape consistency.
2.4.3.2 3.2 Extruder
Hardware Considerations EXTRUDER HARDWARE
CONSIDERATIONS
Extruder Feed Hopper
Extruder Hardware
Considerationsxt
Extruder Feed Hopper
·
Hopper design is important for feeding the
material into the extruder. The pitch
on the hopper should be steep enough to allow the material to flow freely. Staineless steel hoppers also offer the
surface finish that can help flow the material. A material level control or sensor should be in the hopper to
alarm an operator should the material stop flowing or run out of material. Dryers at the throat also assist in the
processing.
Extruder Feed Throat Extruder Feed Throat
·
The feed throat of the extruder is another
important consideration for feeding the material on to the screw. There are straight and tangential throats
and the material being processed will help dictate
which is most effective.
·
With the advent of a grooved or smooth bore at
the feed throat opening, some materials such as LLDPE have
been found to feed better on a grooved feed section while others require a
smooth bore.
·
The opening of the throat needs to be sufficient
to allow the material to feed easily and is dependent on the pellet/flake size
and density.
·
Cooling at the throat is often done with air,
water or glycol. Keeping the material
from melting too early in the process will avoid bridging at the throat and
allow the screw to feed the material more freely.
Extruder Barrel Extruder Barrel
·
Consideration to the material used on the barrel
lining is important when using
recycledusing recycled material. Since foreign particles may be present, it is important
to have good wear resistance. Premature
wear or excessive clearances between the barrel and the screw will effect how
well the machine processes.
·
L/D ratio – The barrel should have a long enough
L/D (length over diameter) to process the material effectively. It is generally recommend that the L/D range
from 24:1 – 32:1 for extruders and 18:1 – 24:1 for injection molding
machines. The equipment design may also
effect how long the L/D can be.
·
Temperature sensing devices are used to sense
the temperature in the barrel and indicate how the material is processing. These should be located in 6-12 zones
throughout the machine and monitored regularly.
·
Heating and cooling on the barrel will keep the
process stable. Heater bands and
cooling channels should be in good working condition and calibrated regularly.
Extruder Screw Extruder Screw
·
Extruder Screws should be designed for the
material being used. There are many
general purpose screws that will process a range of materials. A specially designed screw will offer
process optimization and can improve productivity.
·
Screw wear should generally not exceed
.012-.015. Although some materials are more forgiving, it is recommend
that the screw be replaced after
excessive wear is detected.
·
Extruder Drive System Extruder Drive System
·
It is important that the appropriate HP rating
be sufficient. of turn the screw. Accurate feedback of motor speed should also be
available.
·
The drive system should be protected from over load
should the material viscosity change, causing a problem with the material feed.
·
Motor vibration and misalignments should be
checked annually.
Extruder Tooling Extruder Tooling
·
The appropriate base material for the tool
should be considered for optimizing the life and continued accuracy of the tool.
·
The tool should be cleaned regularly and kept in
good condition.
·
The tool design should consider balanced flow
and velocity profile, optimum land length and entrance angle, as well as
surface coatings to reduce slip/stick effects.
·
The breaker plate geometry should avoid any dead
spots where material can hang up and degrade.
·
When putting in a screen pack (recommended for
recycled materials) it is important to consider the shear and pressure effects
it will have on the process. Automatic
screen changers are recommended.
·
Die position and concentricity are important
aspects to the optimization of the process as well.
Water BathWater Bath
·
The water bath is used for cooling the plastic
and aids in consistent product. It is
important to have temperature control and proper control of turbulence.
·
Cooling rate is important for the
crystallization of the material.
Vacuum SizerVacuum Sizer
·
Temperature and vacuum control are important to
maintain the integrity of the vacuum.
Appropriate vacuum should be present for the product.
·
It is important to seal the tank lid.
Product Take-Off systemProduct Take-Off System
·
Feedback and tensions control are controls are
important for the take-off equipment.
This can be obtained through P.I.D. algorithms. The belt puller centerline alignment should
be aligned with the die centerline and the belt pressure should be evenly
distributed.
34.0 TECHWORKS
The following is the
second extrusion
molding testing relating to the plastics extrusion molding
technical assistance project and was prepared by Techworks. PDM is a custom
extrusion company located in Denver, Colorado.
This study was performed on a plastic fence line.
Equipment: 3 ½”, 36:1 Akron Extruder, PAK
350
Two
Stage Screw
2 2 station Maguire Proportional
Loader Vacuum tanks.
A
puller and a chop saw.
Product: 1” x 8” board of lumber
Material: Dupont’s Tyvek Reprocessed
Pellet, Natural
Talco’s
washed HPDE flake
Purpose: The purpose of this second
run was to take a closer look at what was happening between the 20% and 40%
batches that were run during the first testing. There
was We had a failure at the 40% level, but success eded at the 20% level. Closer examination was needed to see We
wanted to examine closer where the failure was starting.
It Note: It should be noted that this second testing was
performed on a different machine than the first testing. The second testing used a This machine
that was is larger
in screw, barrel, and
throat sizes. All of which awill effected the processing of this material. The L:D ratio on theis
screw required s
higher Amps, as well as, lower Rams, due to the size increase in comparison to the
first run. The product was is also
larger and required ing
a larger die. This information should be taken into
consideration when comparing the results from the two different test times.
When we arrived, tThe machine operated ran finewell and was was running
100% reprocessed Tyvek pellets. Machine
was running good product. The
settings were as follows:
RPM: 35
AMP: 81
PSI
(head): 1400
Melt
Temperature: 363
Barrel Temp Settings:
Zone 1 (rear) 345
Zone
2 351
Zone
3 355
Zone
4 345
Zone
5 350
Zone
6 (Die) 340
Gate 330
3.1 4.1 ProcedureProcedure
Although there was a two-2 station
proportional loader on the machine, the material was hand- blended
because of the flake. Blenders are
available that will handle flake and should be considered if the project progressed. moves forward. Blends of 25%, 30% and 35%
flake to pellet were prepared.
The 25% blended
natural material was added to the process.
The
material was run until a consistent product was achieved. White color concentrate was added at a 2 1/2%
letdown ratio. The
process was stable and the following was observed: until We ran this material
until we got a consistent product. We then added white color concentrate at a
2-½% letdown ratio. The process was
stable and we observed the following:
|
|
25% Natural
|
25% w/color
|
|
RPM:
|
35
|
35
|
|
AMP:
|
80
|
84
|
|
PSI (head)
|
1500
|
2000
|
|
Melt Temperature
|
362
|
362
|
|
Barrel Temp Settings:
|
|
|
Zone 1 (rear)
|
344
|
345
|
|
Zone 2
|
350
|
350
|
|
Zone 3
|
354
|
355
|
|
Zone 4
|
346
|
347
|
|
Zone 5
|
349
|
350
|
|
Zone 6 (Die)
|
340
|
340
|
|
Gate
|
340330
|
330340
|
25%
Natural 25% w/color
RPM: 35 35
AMP: 80 84
PSI (head): 1500 2000
Melt
Temperature: 362 362
Barrel Temp
Settings:
Zone 2 350 350
Zone 3 354 355
Zone 4 346 347
Zone 5 349 350
Zone 6 (Die) 340 340
Gate 330 330
After running the
completion of the batch of 25% mix through, the we started the 30% batch was started.
The following was
observed:We observed the following:
30%
Natural 30% w/color
RPM: 35 35
AMP: 86 85
PSI (head): 2250 2000
Melt
Temperature: 365 362
Barrel Temp
Settings:
Zone 1
(rear) 346 344
Zone 2 350 350
Zone 3 355 355
Zone 4 345 345
Zone 5 350 349
Zone 6 (Die) 343 338
Gate 330 329
|
|
30% Natural
|
30% w/color
|
|
RPM:
|
35
|
35
|
|
AMP:
|
86
|
85
|
|
PSI (head)
|
2250
|
2000
|
|
Melt Temperature
|
365
|
362
|
|
Barrel Temp Settings:
|
|
|
Zone 1 (rear)
|
346
|
344
|
|
Zone 2
|
350
|
350
|
|
Zone 3
|
355
|
355
|
|
Zone 4
|
345
|
345
|
|
Zone 5
|
350
|
349
|
|
Zone 6 (Die)
|
343
|
338
|
|
Gate
|
330
|
329
|
After running the
completion of the batch of 30% mix through, the we started the 35%
batch was
started.
The following was observed:We
observed the following:
|
|
35% Natural
|
35% w/color
|
|
RPM:
|
35
|
35
|
|
AMP:
|
84
|
81
|
|
PSI (head)
|
2000
|
2000
|
|
Melt Temperature
|
362
|
361
|
|
Barrel Temp Settings:
|
|
|
Zone 1 (rear)
|
345
|
344
|
|
Zone 2
|
350
|
350
|
|
Zone 3
|
355
|
355
|
|
Zone 4
|
345
|
345
|
|
Zone 5
|
351
|
349
|
|
Zone 6 (Die)
|
339
|
340
|
|
Gate
|
330
|
330
|
34.2 Observations 35% Natural 35% w/color
RPM: 35 35
AMP: 84 81
PSI (head): 2000 2000
Melt
Temperature: 362 361
Barrel Temp
Settings:
Zone 2 350 350
Zone 3 355 354
Zone 4 345 345
Zone 5 351 349
Zone 6
(Die) 339 340
Gate 330 330
·
The flake ranged in size from .300 -
.700. In a random 1 cup sample, we
found contaminants were found and consisted of the to
consist of the following:
·
Approximately 7,000 –
8,000 parts
Contaminants 53 parts
Labels – 21 parts
Plastic – 32 parts
This
representeds
approximately ½% foreign particles present in the material. The plastic contaminants appeared to be
other mixed bottles and plastic caps.
The labels included paper, plastic and printed plastic. (Data from first run, same gaylord of
material was used.)
·
Product Quality
0% Flake – In a 14 linear inch sample the following was we found:
(Data from the first test.)
0 non-melts
1 black spec
no color contamination
When
the following data was collectedcollected, a fifteen 15 linear
inch sample, per percentage, was examined at a distance of 18 inches. Non-melt iwas a form of
contamination and
wasbut is separated out to show the
defects causing sink versus non-sink areas.
The non-melt caused sink marks. Therefore, the contaminant numbers do not include the non-melt
contaminants.
25% Natural
Flake 25% Flake with Color
0 non-melts 0 non-melts
0 contaminates 2
contaminates
5 color dispersion streaks 0 color streaks
5 black specs 7 black specs
30% Natural Flake 30% Flake with Color
6 non-melts 7 non-melts
5 contaminants 0
contaminants
1 color dispersion streak 1 color
streaks
2
black specs 0
black specs
35% Natural Flake 35% Flake with Color
16 non-melts 6 non-melts
7 contaminants 3
contaminants
2 color dispersion streaks 0 color streaks
2 black specs 0
black specs
34.3 Recommendations and
conclusionsRecommendations and ConclusionsRecommendations and
Conclusions
There was evidence of
labels and some non-melted pellets in the non-colored parts. The contaminants were less evident in the
colored product. No changes were made
to the processing conditions of the extrusion machine at any time through the
run. The water temperature did vary between
60 to 85 degrees in
the tanks. The product witnessed
several sink marks at the 30% and above ratios. There
was no We did not have troubles problem holding
the profile until we got up to ththe 35%
mixture. The We
blew the vacuum was blown at
one time due to a through hole in the extrusion.
It appeared that at
25%, the
processing system performed near normal,
(material had to be hand blended), with no problems with the feed system,
extrusion operation, maintaining integrity of profile through vacuum tanks,
cooling process, puller and chop saw.
Product had
to will have to be examined by the
customer to determine whether the quality was will be acceptable
and comparable to the standard product with 100% DuPont pellets. There was We did see some
contamination from labels or foreign plastic in all product,products and
color contamination from foreign plastic in natural-colored samples.
During the 30% mix
test, the processing system performed near normal,
(material had to be hand blended), with no problems with the feed system,
extrusion operation, cooling process, puller and chop saw. The integrity of profile coming out of the
die seemed a little more flimsy but no adjustments were made. Product will have had to be
examined by the customer to determine whether the quality was will
be acceptable and comparable to the standard product with 100%
DuPont pellets. There was We
did see more contamination from labels or foreign plastic causing
sink marks and
it was , which we would assumed that this would
cause the product to be rejected. Color
contamination from foreign plastic in natural-colored samples continued.
The 35% blend had no
problems with the feed system, extrusion operation, maintaining integrity of
profile through vacuum tanks, cooling process, puller and chop saw. The increased flake and foreign particles
caused more sink marks in the product.
A void did cause a hole in the product at one point, causing a break
in the vacuum. This was quickly
corrected and didn’t effect the rest of the process.
The customer did not has
yet to examine the product run in this test and of course has the
final say in the quality of his product but but it would
seem from the results of these tests that above test that a blend at 25%
would still provide a product of acceptable visual quality. It could also be concluded that larger
equipment and product could make it easier to run larger percentages
.
3.4
Equipment Suppliers
t
Equipment should meet
the specifications for the material and product being processed. The requirements change by product and
need. The following considerations
should be made when choosing equipment.
Included in this section are reputable suppliers for each of these
products (see
following page). This list does
not include all suppliers, nor it is it intended as a recommendation by this
project. It is intended only as a
reference list. Complete lists of
suppliers can be obtained by multiple sources.
Some recommended sources are Modern Plastics Encyclopedia, Plastics
Technology Handbook, www.plasticsnet.com
and the Society of the Plastics Industry.
Primary Processing Equipment, Extruders and
Injection MoldersPROCESSING EQUIPMENT, EXTRUDERS AND INJECTION
MOLDERS
Feed Hopper
Hopper design
Material level control
Drying capabilities
Feed Throat
Material
Straight/Tangential
Grooved or smooth
Opening (length/width ratio)
Cooling (water/air/glycol)
Inside Diameter (straight/undercut)
Barrel
Material
Iron content (flouropolymer)
L/D
Temperature sensing locations
Heating/cooling
Barrel alignment/barrel support
Barrel wear
Screw
Appropriate design for the material
Screw tolerances
Radial flight clearances
Drive system
Appropriate HP rating
Accurate feedback of motor speed
Analog vs. digital vs. servo
Appropriate gear reduction
Overload protection
Vibrations (motor or misalignment)
Instrumentation/sensors
Appropriate pressure transducers
Thermocouples
T/C condition
T/C mounting in well
T/C cold junction compensation
PID Capable temperature controllers
PID/Adaptive Process Pressure Controller
Potentiometer for speed control
Tooling
Appropriate base material
Appropriate cleaning techniques
Velocity profile/balanced flow
Optimum land length
Optimum entrance angles
Surface coatings
Breaker plate/nozzle geometry
Screen pack assembly
Tooling surface finish
Optimum temperature control
Concentricity/thickness adjustment
Die position
Extruder
Suppliers
·
Akron Extruders, Inc.
·
Cincinnati Milacron
·
Conair Gatto Group
·
Davis Standard
·
HPM
·
Wayne Machine and Die
Injection Molding Machines
Suppliers
·
Cincinnati Milacron
·
Demag
·
HPM
·
Nissei
·
Toshiba
·
Van Dorn
Temperature/Pressure Controls
·
Barber Colman
·
DME
·
Fast Heat
·
IMS
·
Industrial Heater
·
RJG
·
Tempco
·
Watlow Electric
Auxiliary Equipment
Conveying and loading
equipment
·
Colortronic
·
Foremost
·
Matsui
·
Motan
·
Novatec
·
Process Control
·
The Conair Group
Metering and Feeding
Equipment
·
Accurate
·
Colortronic
·
Hydreclaim
·
Maguire
·
Motan
·
Novatec
Resin Drying
·
Colortronic
·
Matsui
·
Motan
·
Novatec
·
Process Control
·
The Conair Group
·
Unidyn
Screws
·
Cincinnati Milacron
·
Davis Standard
·
HPM
New Castle
·
Spirex
·
Xaloy
Barrels
·
Bernex
·
Wexco
·
Xaloy
Pelletizers and Dicers
·
Cincinnati Milacron
·
Davis Standard
·
Gala Industries
·
Hydreclaim
This is a list of
primary equipment used in manufacturing plastic products for virgin and
recycled material. Original eEquipment
mManufacturers
(OEMs) also
provide complete packages of equipment.
Date: 10 August 1998
Subject: Technical Assistance Project at TechWorks
TechCenter
The TechCenter at TechWorks TechCenter is
a training facility for the plastics industry and is located in Denver, Colorado. This study was performed on an injection
molding press at in the
molding laboratory.
Equipment: 220
Ton HPM Injection Molding Machine
General
Purpose Screw with a 23 ounce barrel
RJG
DartScanner for electronic data collection
Product: The
mold used was an obsolete bezel from an electronics company.
Material: Post
Consumer washed flake.
Notes: The molding machine was
set up with cavity pressure transducers in the tool in
two locations. One at post gate (just
after the nozzle where the plastic enters the mold, and the second at end of fill (the last area
in the tool to see plastic during the fill stage of processing). The transducers awere hooked up to the DartScanner and data were wais
collected; . The data includeds
pressure in the cavity. By monitoring pressure in the cavity, we can monitor pressure can be monitored at the end of fill (a general rule is that if the
pressure remains at 3,000 psi at the end of fill, with the same fill time, you
can duplicate identical parts regardless of change in material viscosity). This
technology introducess
a “scientific” approach to injection molding and removess
variables in the process which do not have a specific impact on the
process.
The advantage of this technology with recycled
content material is the ability
for the machine (if the machine is load- compensated and not pressure- limited)
to duplicate part dimensions regardless of material variation.
4.1
Procedure
Procedure
The following material was used:material
used was as follows:
·
Talco HDPE flake hand mixed at ratios of 20%,
40%, 60%, 80% and 100%.
·
Ecoplast HDPE flake hand mixed at ratios of 20%,
40%, 60%, 80% and 100%.
·
100% HDPE Repelletized.
·
100% PP Repelletized.
·
100% PCR crate and barrel regrind.
·
100% PCR dairy tub regrind.
·
100% PP scrap.
4.2 Observations
·
We were able to make aAcceptable
product was able tocould be made with identical set--ups
on the machine for the material.
·
We were uUnable to
process the PP scrap material because of high levels of contamination content
in the material.
·
The dairy tub regrind material was extremely
runny with a viscosity similar to water.
We were uUnable to
maintain it in the barrel and it immediately clogged the mold, which required a
complete teardown and clean out of the machine.
4.3 Recommendations and
Conclusions Recommendations and Cconclusions
·
The material processed fairly consistently
across- the- board in terms of reasonably acceptable
parts. The best parts were seen in the
40%-60% blends of repelletized material blended with virgin.
·
The repelletized material processed the best.
·
The parts did not require high dimensional
tolerances for the purpose of this test but the finish and overall dimensions
were consistent.
·
Although cycle times were the same for all
parts, improvements could be made with a screw designed for PE or PP if this
makes sense for the processor. However, Tthe GP screw
design however was acceptable.
·
We used 25% of the shot size of the
barrel was
used and there
was no had no burning related to foreign
particles in the melt. It is We rrecommend
that the barrel size be kept between 35% and 50% of the overall shot to prevent
possible degradation due to residence time in the barrel.
·
Some contamination was evident but did not pose
a problem for this particular job.
·
It is recommended We recommend that
the flake be used with some carrier of virgin material. This would be best be
best be achieved with a
blender on the throat of the machine for accurate metering. Since the material was fed, we hand fed the
material, no we did not experience bridging was
experienced. However, , however this
would most likely occur if the screw was not designed for flake (deeper feed
flights) and it was fed at 100%.
·
It is We recommended that the
supplier dry the material. PP and HDPE
are not hygroscopic materials (meaning they absorb moisture naturally) and we
feel the moisture in the material was “around” the material and
not trapped in the material. This
indicated s that it was
not properly dried after washing at the supplier.
5.0
Report from TechWorks on
Physical Testing ResultsREPORT FROM TECHWORKS ON PHYSICAL TESTING RESULTS
The following information references the
Date: 26
October 1998
Subject: Technical Assistance Project,
Injection Molding and Testing, by the Plastics Research and Education
Center of Ball State University.
Ball State University is
located in Muncie, Indiana. The
Plastics Research and Education Center is directed by Dr. Jerry Wickman. 5.1
Process and Test Criteria
Process and Test Criteria
TensileTensile
·
Tensile specimen was consistently placed
gate down in the jaws of the machine.
·
Ejector pins faced away from the operator.
·
Speed of pull = 2 in./min.
·
Load range = 100,000 psi.
·
Thickness = .125 in.
·
Width of part = .5 in.
·
Gage length = 2 in.
·
Machine = Instron, Model #1011, Tensilometer.
Notched Impact Notched Impact
·
Test specimen cut in half.
·
Impact specimen was of non-gated side, rounded
surface up.
·
Hammer weight = 8.313 lb. Force.
·
Machine = Tinius Olsen, Model #892 (Impact
Display Model).
·
Machine = Tinius Olsen, Model #92T Impact
Testing Machine.
Melt IndexMelt Index
·
ASTM D1238 / D1248.
·
PE = 190*C, 2.16 kg weight.
·
PP = 230 *C, 2.16 kg weight.
·
Machine = Tinius Olsen Extrusion Plastometer,
Model # AD987.
·
Scale = Ohaus, Model # E120.
Processing Processing
·
PP = 100 *F Thermolator Temperature.
·
PE = 70 *F Thermolator Temperature.
·
PP = 430 *F All Zones.
·
PE = 410 *F All Zones.
·
Machine = Sandretto 60 ton Injection Press,
Model # S.7.60.
·
Thermolator = Conair Tempro, Model # EC1-DI.
·
ASTM Test Bar Mold.
Materials Materials
·
Talco’s washed HDPE flake.
·
Eco Plast’s washed HDPE flake.
·
Alathon, Lyondell PE Resin, Lot # 614040 H5618
Virgin.
·
Eco Plast Repelletized HDPE.
·
Eco Plast Repelletized PP CO 8.
·
CPR Post Consumer Scrap, PP Flake.
·
CPR Post Consumer Dairy Tub Scrap, PP Flake.
·
CPR Post Consumer Bucket and Crate Scrap, PP
Flake.
The material was
shipped to Ball State in weighed- out
batches. The batches were not mixed
prior to shipment. The mixes where
labeled the as: following.
Mix
(Material) 1: 20% Talco Flake + 80% Virgin
Mix
(Material) 2: 40% Talco Flake + 60% Virgin
Mix
(Material) 3: 60% Talco Flake + 40% Virgin
Mix
(Material) 4: 100% Talco Flake
Mix
(Material) 5: 20% Eco Flake + 80% Virgin
Mix
(Material) 6: 40% Eco Flake + 60% Virgin
Mix
(Material) 7: 60% Eco Flake + 40% Virgin
Mix
(Material) 8: 100% Eco Flake
Mix
(Material) 9: 100% CPR Scrap
Mix (Material) 10: 100% CPR Dairy Tub Scrap
Mix (Material) 11: 100% CPR Bucket and Crate Scrap
Mix
(Material) 12: 100% Eco Repelletized HDPE
Mix
(Material) 13: 100% Eco Repelletized PP CO 8
5.2 Procedure Procedure
The test bars were run
at the process conditions shown above.
Random sampling in this study was conducted as follows. Thirty pieces of each material were produced
for each test of the study. Each test
category (impact, tensile, etc...) had a
bag containing all thirty specimens.
The sample size for each category was N=5. Five samples were pulled at random from the bags. These five samples were then used for the
testing procedure and the remainders were left undisturbed.
5.3
Observations Observations
·
Material 10, the dDairy tTub
sScrap,
was not suitable for processing due to glass, aluminum and nails found in the
regrind. See the returned
sample.
·
By studying the PE, Rank Order Table in the Appendix C, it was found we find that the materials, for
the most part, ranked
themselves in order by the percentage of regrind (or flake), which was expected. Which we would
expect. HHowever, the
mixes with large percentages of regrind (flake %) actually had
higher tTensile
strength results, as well as, higher iImpact
strength. This would show that tThe more
regrind (flake) the mixes had, the stronger they were in iImpact
and tTensile. The repelletized PE mix, which is 100%
regrind, was the highest in the Tensile test results and fell mid- range
in the mMelt
and iImpact.
·
The higher percentage of PE regrind mixes also
had lower mMelt
iIndex
readings. The This
shows
that the mmaterial was harder to push as the regrind
percentage (flake percentage) went upincreased.
·
The PP Rank Order Table found in Appendix C was is a little
harder to interpret and see a pattern because there were
only due to only
having three material batches. and it was . It is harder to see a
pattern. The mMelt
iIndex
resultsts
showed
that the Repelletized PP was actually the harder of the three to push, having a
lower mMelt
iIndex
number.
·
The 100% CPR Scrap had the highest tTensile
of all the materials tested, as well as , the
highest mMelt
iIndex. However, its iImpact sStrength
was among the lowest.
·
The 100% CPR dDairy
tTub
sScrap
was not processed due to contaminates and therefore could not be tested by tTensile
or iImpact. It was tested by mMelt
fFlow
and had a low index rating of
1.864 g/10min, which would rank it third from the bottom.
·
The 100% CPR Bucket and cCrate
sScrap
showed the lowest tTensile
strength and iImpact
strength of all the materials tested.
It did rank in the top three of the mMelt iIndex
results.
5.4 Recommendations and
Conclusions
Recommendations and
Conclusions
It was surprising
that The fact that the higher percentage
batches were showing higher strengths, since this was not expected. surprised me. I did not expect that. I
think that It is possible that the maybe the virgin
material we used
was of lower
strength than the mixture of regrind that wase
received. Unfortunately, there is really
no way to know what bBrands of
PE have been mixed into the regrind.
I am waiting to get
some data on the virgin material we mixed with the flake. I am hoping that this will give me some
insight into the results that we have seen.
The manufacturer is to fax me the information soon. I will gladly send an addition for the
report when I get that information.
I
would think that these results would call for further testing since they seem
to be the opposite of the expectations molders have for regrind materials. People expect their properties to
deteriorate after being
EVALUATION REPORT
Evaluation Report: Summary
of Survey of Colorado based Based Plastic
Molders
1. # Responses for:
·
Injection
Molders: 21
·
Extrusion
Molders: 4 (sheet =2)
·
N/A Calls:
19 disconnected/out of service or don’t mold)
2. Types of Resins used:
HDPE - 12, LDPE – 6,
PP – 14, PVC – 6, ABS - 7
Others:
·
All
Engineering Grades
·
Peek,
Ultem, PC, PC/ABS Blends
·
Commodity
to Engineering Grades
·
Nylon
·
PETG
·
PS
·
Commodity
through Engineering Grade, Many with Fillers
·
PUR, PE,
Nylon
·
Urethanes
and Nylon
·
Expanded
Polystyrene ( Not typical inj. molder)
·
PC, PC/ABS
Blends, PPE
·
Medical
Grades, PVC
·
PC/ABS,
Nylon,
·
200 types,
incl. PC, Nylons, & Glassfilled Materials
·
Commodities
& Engineering Grades
·
PC,
Acrylic, Peek, PPA, Teflon, PBT
·
HIPS and
Engineering grades
·
Engineering
grades, rarely use PS, PE
3. Do you use PCR Pellets?
Regular - 5
Selected Products - 2
Infrequently – 4
NO - 13
Other comments:
·
No and
Never Will.
·
It’s all
they run.
·
No
applications.
·
Combination
of PCR and PIR varies. Get PCR from
Indiana.
·
Get regrind
from CA, 500,000 lb./month. 80% is PCR.
·
Specified
for selected products
·
Only
recompound
·
They have a
program where their customers return the parts for reuse.
·
The FDA
frowns on the liabilities of using regrind for medical parts.
4. Do you use washed flake or clean industrial
regrind?
Regular - 7
Selected Products - 1
Infrequently - 3
No - 12
Other comments:
·
Not unless
in-house regrind. Job dependent.
·
Some
in-house flake, rarely.
·
Use some
regrind, new at molding.
·
Run pellets
only, sell all regrind.
·
Run in
house regrind
·
No. All pelletized
·
Buy to
grind, as well as, ground.
·
Aren’t now,
have and still capable.
·
Run
internal scrap
·
Grind own.
·
In house
·
Don’t use
flake they recompound their regrind.
·
Computer
parts that are internally used.
5. Have you ever used recycled materials, esp.
washed flake?
Yes
- 14
No
- 2
Comments, Yes:
·
Had a bad
experience. PC repelletized material,
parts shattered.
·
Use
Internal
·
It’s all
they run.
·
Customers
limit their use.
·
In house
regrind.
·
Tried, had
feeder problems.
·
Internal.
·
Only run internal,
have FDA Tracability requirements
·
Depends on
Product
·
Post
Industrial
·
As long as
it meets requirements.
·
Limited use
do to computer industry.
·
Medical
products only run virgin. Customer’s
choice, FDA may have say.
·
Own after
recompounding.
Comments, No:
·
Too color
oriented, 90-95% spec. color
·
Medical
products, design for no regrind.
Tracability by lot too difficult with regrind.
6. What are your requirements for using
recycled materials?
·
Internally
generated, max of 25%, per customer, Job by Job, and cost of virgin.
·
Conforming,
cosmetic, dimension stability, non-contaminated.
·
Only use
internal.
·
Use all
in-house generated, also use medical molded scrap (local).
·
Don’t, they
sell 95% of own scrap. They have fast
enough cycles to accumulate quantities.
·
Must meet
virgin specs. and it doesn’t.
·
Natural
material, Melt, density .92-.95
·
Rigid PVC,
relatively
·
FDA 100%
tracability back to virgin
·
Non
contaminated, Low amount of fines.
·
The product
drives the material usage decisions
·
Up to
customer.
·
Use
grindings, don’t repelletize.
·
Project
Dependent, UL Ratings
·
Customer’s
regulate/specify. Selected in design
stage.
·
Project
Specific
·
They
recompound to out gas.
·
Customer
calls out specs. If UL Rated then max.
of 25% can be used. Like to use min of
runner weight. Or even 100% if possible
and customer approved.
·
Very
difficult. Must run the right type of
material for the right process. Inj to
Inj, Blow to Blow.
7. What are you equipment capabilities for
using recycled materials?
·
Have 5
grinders and a gravometric loader or pre mix.
·
Fine
·
Fine
·
Large
grinders.
·
Grinder,
not set up for contamination or separation of mixed materials.
·
Can do.
·
No
problems, Control of Cleanliness, Throat metering.
·
Vacuum
loaders, no problems
·
No
limitations.
·
No
equipment problems, light colored flake does burn/discolor easily.
·
Not sure.
·
Have
grinder, sell regrind, and do run on non-medical jobs.
·
Grief for
cleaning by the operators.
·
Not limited
·
Have beside
the press grinders. If blades get dull
get problems. Too many fines, poor flakes, non-uniform for feeding problems.
8. Would you use a technical assistance
program by the State?
Yes - 5
No - 7
Maybe - 4
Other comments:
·
Possibly,
depends on what is required of them.
They are recycling other materials such as packaging, in house, too.
·
No, what
are they going to tell me?
·
No, Don’t
know how helpful it would be.
·
Probably.
·
Can’t see
using PCR and other recycled, there is no control over and it is too expensive.
·
Certainly
·
Probably
not.
·
Doubt it.
·
Possibly,
I’ve been talking with Dave Kahl, Yes then.
·
Use all
they can internally, it is “free money”
·
For a PP
premold, which must be non-conductive and has no appearance concerns.
·
Absolutely
Not
·
It’s
possible. Learn more, become better
user.
·
Would like
to see a consortium (collection site) for regrind sellers so material could be
sold by volume. Thinks buyers are
screwing sellers.
·
Not really
being used.
·
How would
it assist? I would need to see value
before using.
·
In supply
of regrind
·
Their
customers drive them. “hog tied”
·
Won’t
matter, you can’t even get companies to run PIR.
9. Specifically what type of information or
services do you think you might need?
·
Information
on Resources. A market is needed for
mixed regrinds. (Some one in New Mexico
is mixing pellets with a binder?) Need
a clearinghouse to run internal regrind through, give away, rather than
landfilling. Cost / quantities prohibit
it
·
None, They
don’t know my product to be able to tell me what I can or can’t use.
·
Technical
Data, Effect on Properties
·
Technical
Training, Sorting of materials, Testing to determine what type of resin it is.
·
New at
molding, need knowledge, where to buy materials, spec. regrinds?
·
Technical
back up, don’t have capabilities to do in house.
·
Testing,
melt, density, elongation, tensile. To
determine if “Slip” or contamination.
Underwrite or fund to put in a
pelletizing line? Need a market
here, if enough collected he would buy
locally.
·
Nothing
Specific.
·
They sell a
lot of sheet yearly. Estimate only
getting 15% back. Would like to get
more back. Tracability? Don’t want it to go to landfill. Current pricing of virgin.
·
Only using
plastics as a binder. Very little
usage. Not applicable. (Coors Ceramic)
·
All of the
above, mainly to find suppliers
·
Specifications
are very important, Tech. Data. They
run 500-1000 lbs./month.
·
Leads into
projects using recycled materials
·
If a job
came up for use then need help.
·
Thinks it
is a great idea. Go to the OEM,
customer/Designer. They would submit a
list of customers.
·
Show me a
benefit to regrind all my scrap. Who
will I sell it to? Costs to regrind, no
profit.
·
Get in at
design stage, Educate at the design level.
Show cost saving vs. properties.
·
They try to
lead customers towards reprocessed materials if suited towards project. Some cases they have some input other times
none.
·
Need a
product, extruded lumber, decking, and benches, roofing tiles, extrusion.
·
Empak has a
processing center in Houston, looking
to move it to Colorado, he will be a resource for us.
·
Must find a
market and need collection facilities.
·
Not
directly – through FDA, would give material too? Even with extra measure being taken to pull material aside, still
couldn’t guarantee cleanliness.
·
If you
could prove to the customer/OEM that a larger % of regrind wouldn’t jeopardize
the properties. Or more importantly
convince UL.
The following are the questions and responses from Gene
Pendery, President of Recycled Plastic Products, Inc., the manufacturer of the
plastic lumber product line we used for testing in the extrusion technical
assistance project. His responses are
in Italics.
1. Have you decided whether to use washed
flake?
Not yet – still
investigating.
2. If yes, can you estimate how much
recycled washed flake you might substitute for recycled pellet and/or virgin
resin in the next 2 – 3 years?
Best guess would be to
blend 15 – 25% with repro pellets.
3. Would you have been able to decide whether
to use washed flake without the test results?
No.
4. Did the test provide you with
sufficient data for you to make a decision on whether to use washed flake?
Probably.
5. Did the test and equipment
recommendations provide you with sufficient data about how washed flake could
be used in your system?
Yes.
6. Would your company have performed the
tests without the intervention of this project? If yes, can you estimate the
timeline for when you may have done so?
No.
7. Were you satisfied with your level of
involvement in the project?
Yes.
8. How great of a time commitment was
this project for you? Did it require more or less time than you had
anticipated?
About as expected.
9. Prior to this project, have you
attempted to find information about alternative feedstocks or other
environment-related issues? If so, from what source did you get the
information?
Yes – various suppliers
and consultants.
10. State government is considering
whether to implement an ongoing technical assistance program. Would you be
likely to use such a service?
Yes.
11. Specifically, what types of
information do you think you might need?
In what form would you like this information?
Continuing updates on
materials available; equipment to make it work.
12. What other feedback or suggestions do
you have about this project?
Program was well thought
out and performed.
The following are the questions and responses from Al
Chavez, Extrusion Department manager for the custom molder, Plastics Design and
Manufacturing, of the plastic lumber product line we used for testing in the
extrusion technical assistance project.
As the custom molder, he molds what his customers tell him to, so the
first few questions were not applicable.
I only asked him the final questions re. the technical assistance
project. His responses are in Italics.
1. State government is considering
whether to implement an ongoing technical assistance program. Would you be
likely to use such a service?
No, the technical
assistance would need to be very advanced, current and applicable for the
technology in question. We have in-house technical expertise and do not think
the State could provide any expertise beyond ours. The custom extrusion business is very competitive and closed to
exchange of information.
2.
Specifically,
what types of information do you think you might need? In what form would you like this
information?
Product design and
extrusion die design for the use of recycled resins, to account for differences
in processing behaviors. For example,
recycled resins experience more swelling in extrusion process than virgin
resins and the die and product design must account for this. Other information might be equipment
recommendations to overcome material shortcomings.
PLASTICS PROJECT SELECTION
CRITERIA & EVALUATION
Attachmentppendix BA:
Plastics Project Selection Criteria & Evaluation
TO: Kelly Roberts
Amy Smith
FROM: Carol Brown
CWC Project Team
DATE: 4/30/98
RE: PLASTIC TECHNICAL ASSISTANCE
PROJECT
Below is an explanation
of the plastic technical assistance project and the project assessment and
ratings. This project was developed by the attendees at the plastic industry
forum and will involve multiple local participants.
(1) Market survey and technical assistance for the use of HDPE and
LDPE washed flake.
These resins have some
established collection and handling infrastructure already, and we have already
identified several manufacturing companies who use recycled pellet imported
from outside of the State. A processing
system to grind and wash these materials could potentially be economically
effective in competition with out-of-state pelletizing operations. The processing equipment required to feed
flakes is different than that for pellets, and most if not all manufacturers in
Colorado are currently only designed, equipped and operated for pellets.
Technical assistance activities:
·
Survey potential
manufacturing markets for recycled materials and develop needs/requirements,
focusing on HDPE and LDPE, and noting all potential opportunities to use washed
flake in substitution for pellets.
·
Create a material
testing model to provide samples of washed flake to a selected manufacturer to
develop, test and demonstrate the requirements for using recycled materials in
their manufacturing process. A range of
usable specification properties could be developed and then tested to validate
the specifications.
·
Provide technical
assistance on feed equipment requirements, and operating procedures for using
the flake material and evaluate the cost-effectiveness of appropriate equipment
modifications for the use of flake instead of or in addition to pellets.
The goal of the project
is to demonstrate the feasibility of using washed flake in place of pellets and
to document the specific blends and material properties which result. The required equipment modifications will be
documented and will include a cost-benefit analysis.
The project involves a
total of 6-8 weeks elapsed time and can easily be accommodated within the
project timeframe
Strong level of interest
from industry players and clearly expressed need for this information;
technical testing facility makes information and results credible and neutral
This project is a
stepping stone to opening up the local markets for washed flake; real world
industry application and experience have been shown to be the best
"sales" tool; project will identify specific companies who are
potential users
Project data will allow
interested manufacturer to apply the information to their process and determine
applicability. However, industry is
always slow to embrace change - especially when it involves risk and virgin
material prices will impact economics of a feedstock substitution; degree of
acceptance is hard to predict
Pellets have been the
industry standard for recycled material yet washed flake can be used in many
applications; this project will provide specific material data and a model to
help potential end users determine applicability to their manufacturing process
and help minimize the risks involved;
Model for material
testing and evaluation could be used in the future for testing other plastic
resin types and other end use applications.
Actual project
participants are small local players but potential range of interested parties could involve some of the larger more influential
companies;
Commitment of company leadership-"champion
of change" 2
The team of participants
are all committed but the nature of the project doesn't lend itself to a single
visible leader; the players include material processors, product manufacturers,
and the technical engineers at the testing facility;All have a vested interest
in the project results
Potential volume is very
significant but conversion of individual manufacturers will be a slow process;
any utilization will be dependent on the development of local wash and flake
capacity
Recycled HDPE and LDPE
are low value materials; project results could lead to substitution of locally
processed flake for out of state pellets and/or local virgin material…all
relatively low value; hopefully results will increase total utilization of
recycled material by COL manufacturers
OTHER PROJECTS CONSIDERED:
Identify existing users
of recycled plastic and collate information on type of resins, quantities,
specifications, and ability to accept pellets, flake or other forms for use.
Develop information on market potential and processing requirements in an
effort to demonstrate economic feasibility of washing and/or pelletizing line
investment.
Project might have
increased local processing capacity but economies of scale of larger out of
state processors would be hard to match.
Transportation savings likely offset by lower processing costs.
Potential to substitute local processing capacity for out of state material but
not necessarily increase volume of material utilized.
Survey companies in
Colorado that generate plastic scrap, identify quantity and type of materials,
and what problems they have finding markets.
The goal would be to increase supply and accessibility of material
available for recovery and reutilization.
This is similar to
efforts underway with EPA/CCEM Waste Characterization project. Multiple steps required to impact actual
utilization of any of this material.
Train operators of
plastics manufacturing equipment in the use of recycled materials. Often the requirements for the use of
recycled materials differ from virgin materials, and operator and product
problems result in the discontinuation of the recycled material. Understanding the differences in material
handling and system operations can optimize material performance.
This applicability of
this assistance would be limited to specific products, types of equipment and
processes. The TechWorks Tech Center is
well situated to provide this kind of training as part of their curriculum.
Market survey and
technical assistance for the use of injection grade HDPE, LDPE, and PP. These
resins have limited collection and handling infrastructure. There are some existing regional markets and
a large number of injection molders in the state. Technical assistance focusing on this group of resins could help
to open up collection, processing and remanufacturing for materials not currently
being recovered.
This project was the
second priority from the plastic industry forum. It has the potential to open up substantial new markets for
recycled plastics in Colorado. However, the challenge of simultaneously
addressing the end user specifications and market barriers as well as the front
end collection and supply issues were a bit daunting for a 4 month project.
This project had too many pieces that would have to all fall in place before
there would be any impact on plastic recycling in CO.
MOLDERS SURVEY FORMS
Injection Molders Survey Form Company
Called:_______________________
Hello, this is Sheri Peterson with TechWorks. We are working with the Colorado Governor's
Office of
Energy Conservation on a project to assist Colorado businesses in using more
recycled materials in manufacturing. We
are particularly interested in plastics manufacturing and the use of recycled
plastics. Would you have time to answer a few questions
about your company's potential to use recycled plastics in your manufacturing?
(if NO, is there another time or person we could call? If NO, thank you, end survey).
1. Does your company do injection molding? (if NO, thank you, end survey) YES NO
2. What resins do you use for injection molding? (e.g.
HDPE, LDPE, others) HDPE LDPE
PP
PVC ABS OTHERS:_________________________________________________
3. Do you use any PCR
pellets, (1) on a regular basis, (2) for selected products, (3) very
infrequently? (1) REGULAR
(2) SELECTED PRODUCTS (3)
INFREQUENTLY
4. Do you use any washed
flake or clean industrial regrind, (1) on a regular basis, (2) for selected
products, or (3) very infrequently? (1) REGULAR
(2) SELECTED PRODUCTS (3) INFREQUENTLY
5. Have you ever used
recycled materials? (if NO, why not, what are barriers?) Would you consider
using recycled materials (or more recycled materials), if it met your
requirements? (if NO, why not, what are barriers?) YES, comments:________________
_______________________________________________________________________
NO, comments:___________________________________________________________
6. What are your
requirements for using recycled materials? (e.g. pellets or flake size,
contamination level and type, resin type, quantity and delivery
requirements, price savings)_________________________________________________________________________________________________________________________________________
7. What are your equipment
capabilities for using recycled materials? (e.g. feeding system -- vacuum
take-up, bulk loading)________________________________________________
________________________________________________________________________
8. Colorado State is
considering whether to implement an ongoing technical assistance program. Would you be likely to use such a service?
(why, why not)_________________
________________________________________________________________________
9. Specifically, what
types of information or services do you think you might need? (e.g. specs on
recycled content products , testing with flake, R&D on new products , tech assistance
with equipment upgrades)___________________________________________
________________________________________________________________________
Extrusion Molders Survey Form Company
Called:_______________________
Hello, this is Sheri
Peterson with TechWorks. We are working
with the Colorado Governor's Office of Energy Conservation on a project to
assist Colorado businesses in using more recycled materials in manufacturing. We are particularly interested in plastics
manufacturing and the use of recycled plastics. Would you have time to answer a few questions about your
company's potential to use recycled plastics in your manufacturing? (if NO, is
there another time or person we could call?
If NO, thank you, end survey).
1. Does your company do extrusion molding? (if NO, thank
you, end survey) YES NO
2. What resins do you use for extrusion molding? (e.g. HDPE,
LDPE, others) HDPE LDPE
PP
PVC ABS
OTHERS:_________________________________________________
3. Do you use any PCR
pellets, (1) on a regular basis, (2) for selected products, (3) very
infrequently? (1) REGULAR (2) SELECTED PRODUCTS (3) INFREQUENTLY
4. Do you use any washed
flake or clean industrial regrind, (1) on a regular basis, (2) for selected
products, or (3) very infrequently? (1)
REGULAR (2) SELECTED PRODUCTS
(3) INFREQUENTLY
5. Have you ever used
recycled materials? (if NO, why not, what are barriers?) Would you consider
using washed
flake (or
more washed
flake), if
it met your requirements? (if NO, why not, what are barriers?) YES, comments:__________________________________
_______________________________________________________________________
NO,
comments:___________________________________________________________
6. What are your
requirements for using washed flake? (e.g. pellets or flake size, contamination level
and type, resin type, quantity and delivery requirements, price
savings)_________________________________________________________________________________________________________________________________________
7. What are your equipment
capabilities for using washed flake? (e.g. feeding system -- vacuum take-up, bulk
loading,
crammer feeding, screen packs in extruders -- continuous screen changers)___________________________________________________________
________________________________________________________________________
8. Colorado State is
considering whether to implement an ongoing technical assistance program. Would you be likely to use such a service?
(why, why not)_________________
________________________________________________________________________
9. Specifically, what
types of information or services do you think you might need? (e.g. specs on
recycled content products , testing with flake, R&D on new products , tech
assistance with equipment upgrades)___________________________________________
________________________________________________________________________
APPENDIX D:
MATERIAL TEST RESULTS
Attachment B: Molders
Survey Interview Forms
