KUUF Social Justice Committee
Summary: This Wikipedia article [below] on Plastics recycling
will tell you as much as or more than you probably want to
know about
recycling plastic.
Waste Management in Houghton (where Hancock
curbside pickup goes, I'm told) recycles only #1 (PETE) and
#2
(HDPE), but the article didn't tell me what one has to do to
recycle
the other kinds (esp. #7, PLA which is the
'what-the-heck-is-it'
category -- a real failure of the system, imo). The best way to
deal with this stubborn, highly complex material, which
requires more
processing to recycle than most others, would still have to
be to
AVOID IT WHENEVER HUMANLY POSSIBLE.
Next time -- the effect of discarded plastic on the oceans
where our
fish comes from.
--
From
Barry Pegg
Below FROM:
http://en.wikipedia.org/wiki/Plastic_recycling
Plastic recycling
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Plastic recycling is the process of recovering scrap
or waste plastics
and reprocessing the material into useful products, sometimes completely
different in form from their original state. For instance, this could mean
melting down soft drink bottles then casting them as plastic chairs
and tables.
Before recycling, plastics are
sorted according to their resin identification code, a method of
categorization of polymer types, which was developed by the Society of the Plastics Industry
in 1988. Polyethylene terephthalate, commonly
referred to as PET, for instance, has a resin code of 1.
When compared to other materials
like glass and metal materials,
plastic polymers require greater processing to be recycled.[citation needed] Plastics have
a low entropy
of mixing, which is due to the high molecular
weight of their large polymer chains. A macromolecule
interacts with its environment along its entire length, so its enthalpy of
mixing is large compared to that of an organic
molecule with a similar structure. Heating alone is not enough to dissolve
such a large molecule; because of this, plastics must often be of nearly
identical composition in order to mix efficiently.
When different types of plastics are
melted together they tend to phase-separate,
like oil and water, and set in these layers. The phase
boundaries cause structural weakness in the resulting material, meaning
that polymer
blends are only useful in limited applications.
Another barrier to recycling is the
widespread use of dyes,
fillers, and
other additives in plastics. The polymer is generally too viscous to
economically remove fillers, and would be damaged by many of the processes that
could cheaply remove the added dyes. Additives are less widely used in beverage
containers and plastic bags, allowing them to be recycled more
frequently.
The use of biodegradable plastics is increasing. If some
of these get mixed in the other plastics for recycling, the reclaimed plastic
is not recyclable because the variance in properties and melt temperatures.[1]
Many such problems can be resolved
by using a more elaborate monomer recycling process, in which a condensation polymer essentially undergoes the
inverse of the polymerization reaction used to manufacture it. This
yields the same mix of chemicals that formed the original polymer, which can be
purified and used to synthesize new polymer chains of the same type. Du Pont opened
a pilot plant of this type in Cape Fear, North Carolina, USA, to
recycle PET by a process of methanolysis, but it closed the plant due to
economic pressures.[2]
Another potential option is the
conversion of assorted polymers into petroleum by
a much less precise thermal depolymerization process. Such a
process would be able to accept almost any polymer or mix of polymers,
including thermoset
materials such as vulcanized rubber tires
and the biopolymers in feathers and other agricultural waste. Like natural
petroleum, the chemicals produced can be made into fuels as well as polymers. A
pilot plant of this type exists in Carthage, Missouri, USA, using turkey waste as
input material. See the main article on thermal depolymerization. Gasification
is a similar process, but is not technically recycling since polymers are not
likely to become the result.
Recently, a process has also been
developed in which many kinds of plastic can be used as a carbon source in
the recycling of scrap steel.[3]
Yet another process that is gaining
ground with startup companies (especially in Australia, United
States and Japan)
is heat compression.[citation needed] The heat
compression process takes all unsorted, cleaned plastic in all forms, from soft
plastic bags to hard industrial waste, and mixes the load in tumblers (large
rotating drums resembling giant clothes
dryers). The most obvious benefit to this method is the fact that all
plastic is recyclable, not just matching forms. However, criticism rises from
the energy costs of rotating the drums, and heating the post-melt pipes.
|
Contents [hide] |
[edit] Applications
Main article: Recycling of PET bottles
Post-consumer polyethylene terephthalate (number 1),
also known as PET, is often used as the raw material for a range of products.
To obtain the pure PET, the recycled items, such as plastic bottles and
containers(the main use for PET), are first inspected for any non PET materials[4].
These materials are then removed and the PET items are sorted into different
color fractions, cleaned, and prepared for processing[5].
This sorted post-consumer PET waste is crushed, chopped into flakes, pressed
into bales, and offered for sale[6].
One use for this recycled PET that
has recently started to become popular is to create fabrics to be used in the
clothing industry[7].
The fabrics are created by spinning the PET flakes into thread and yarn[8].
This is done just as easily as creating polyester from brand new PET[9].
The recycled PET thread or yarn can be used either alone or together with other
fibers to create a very wide variety of fabrics. Traditionally these fabrics
were used to create strong, durable, rough, products, such as jackets, coat,
shoes, bags, hats, and accessories. However, these fabrics are usually to rough
on the skin and could cause irritation. Therefore, they usually are not used on
any clothing that may irritate the skin, or where comfort is required[10].
But in today’s new eco-friendly world there has been more of a demand for
“green” products. As a result, many clothing companies have started looking for
ways to take advantage of this new market and new innovations in the use of
recycled PET fabric are beginning to develop. These innovations included
different ways to process the fabric[11],
to use the fabric, or blend the fabric with other materials[12].
Some of the fabrics that are leading the industry in these innovations include Billabong's Eco-Supreme Suede[13],
Livity's Rip-Tide III[14],
Wellman Inc's Eco-fi(formerly known as
EcoSpun)[15],
and Reware's Rewoven[16].
Some additional companies that take pride in using recycled PET in their
products are Crazy Shirts[17]
and Playback[18].
PVC- or Vinyl Recycling has
historically been difficult to perfect on the industrial scale.[citation needed] But within the
last decade several viable methods for recycling or upcycling PVC
plastic have
been developed.[citation needed]
The most-often recycled plastic[citation needed], HDPE or number 2, is downcycled
into plastic lumber, tables, roadside curbs, benches,
truck cargo liners, trash receptacles, stationery (e.g. rulers) and other
durable plastic products and is usually in demand.
The white plastic foam
peanuts used as packing material are often accepted by shipping stores for
reuse.[19]
In Israel successful
trials have shown that plastic films recovered from mixed municipal waste
streams can be recycled into useful household products such as buckets.[20]
Similarly, agricultural
plastics such as mulch film, drip tape
and silage bags
are being diverted from the waste stream and successfully recycled [21]
into much larger products for industrial applications such as plastic composite railroad ties.[22]
Historically, these agricultural plastics have primarily been either landfilled
or burned on-site in the fields of individual farms.[23]
CNN reports that Indian Dr. S. Madhu
of the Kerala Highway Research Institute has formulated a road surface that
includes recycled plastic.[citation needed] Aggregate,
bitumen (asphalt) with plastic that has been shredded and melted at a
temperature below 220 degrees C (428 °F) to avoid pollution. This road surface
is claimed to be very durable and monsoon rain resistant. The plastic is sorted
by hand, which is economical in India. The test road used 60 kg of plastic
for an approx. 500m long, 8m wide, two-lane road.
[edit] Financial justification
In 2008, the price of PETE dropped
from $370/ton in the US to $20 in November.[clarification needed][24].
PET prices had returned to their long term averages by May 2009.[25]
[edit] Consumer education
[edit] United States
Plastic recycling rates lag far
behind those of other items, such as newspaper (about 80%) and corrugated fiberboard (about 70%).[26]
Low national plastic recycling rates have been due to the complexity of sorting
and processing, unfavorable economics, and consumer confusion about which
plastics can actually be recycled.[27]
Part of the confusion has been due to the recycling
symbol that is usually on all plastic items[citation needed]. This symbol
is called a resin identification code. It is stamped
or printed on the bottom of containers and surrounded by a triangle of arrows.
(See the table in Plastic.)
The intent of these arrows was to make it easier to identify plastics for
recycling. The recycling symbol doesn’t necessarily mean that the item will be
accepted by residential recycling programs.[28]
They just indicate the plastic resin content.[29]
[edit] United Kingdom
In the UK, the amount of
post-consumer plastic being recycled is relatively low[30],
due in part to a lack of recycling facilities.
[edit] Plastic
Identification Code
Main article: Resin identification code
Seven groups of plastic polymers,[31]
each with specific properties, are used worldwide for packaging applications
(see table below). Each group of plastic polymer can be identified by its
Plastic Identification code (PIC) - usually a number or a letter abbreviation.
For instance, Low-Density Polyethylene can be identified by the number 4 and/or
the letters "LDPE". The PIC appears inside a three-chasing arrow
recycling symbol. The symbol is used to indicate whether the plastic can be
recycled into new products.
The PIC was introduced by the
Society of the Plastics Industry, Inc. which provides a uniform system for the
identification of different polymer types and helps recycling companies to
separate different plastics for reprocessing. Manufacturers of plastic products
are required to use PIC labels in some countries/regions [32]
and can voluntarily mark their products with the PIC where there are no
requirements. Consumers can identify the plastic types based on the codes
usually found at the base or at the side of the plastic products, including
food/chemical packaging and containers. The PIC is usually not present on
packaging films, as it is not practical to collect and recycle most of this type
of waste.
|
Plastic
Identification Code |
Type
of plastic polymer |
Properties |
Common
Packaging Applications |
|
|
Polyethylene Terephthalate (PET, PETE) |
Clarity, strength, toughness,
barrier to gas and moisture. |
Soft drink, water and salad
dressing bottles; peanut butter and jam jars |
|
|
High Density Polyethylene (HDPE) |
Stiffness, strength, toughness,
resistance to moisture, permeability to gas. |
Water pipes, Hula-Hoop (children's
game) rings, Milk, juice and water bottles; the occasional shampoo / toiletry
bottle |
|
|
Polyvinyl Chloride (PVC) |
Versatility, clarity, ease of
blending, strength, toughness. |
Juice bottles; cling films; PVC
piping |
|
|
Low Density Polyethylene (LDPE) |
Ease of processing, strength,
toughness, flexibility, ease of sealing, barrier to moisture. |
Frozen food bags; squeezable
bottles, e.g. honey, mustard; cling films; flexible container lids. |
|
|
Polypropylene
(PP) |
Strength, toughness, resistance to
heat, chemicals, grease and oil, versatile, barrier to moisture. |
Reusable microwaveable ware;
kitchenware; yogurt containers; margarine tubs; microwaveable disposable
take-away containers; disposable cups and plates. |
|
|
Polystyrene
(PS) |
Versatility, clarity, easily
formed |
Egg cartons; packing peanuts;
disposable cups, plates, trays and cutlery; disposable take-away containers; |
|
|
Other (often polycarbonate
or ABS) |
Dependent on polymers or
combination of polymers |
Beverage bottles; baby milk
bottles; electronic casing. |
|
|
This section does not cite any references or sources. |
The quantity of post-consumer
plastics recycled has increased every year since at least 1990. In 2006 the
amount of plastic bottles recycled reached a record high of 2.2 trillion
pounds.
The amount of PET bottles recycled
in 2006 increased more than 102 million pounds compared to 2005.
HDPE bottle recycling increased in
2005 to 928 million pounds.
All plastic bottles were recycled at
a rate of 24 percent in 2005.
[edit] See also
[edit] References
- ^ http://cygnus-group.com/use-less-stuff/Paper-and-Plastic-Grocery-Bag-LCA-Summary-3-21-08.pdf
- ^ http://www.allbusiness.com/chemicals/chemicals-overview/9060603-1.html
- ^ Steel
CNN, Accessed 9.11.06
- ^ http://www.rewarestore.com/tech_recycled_pet.html
- ^ http://www.eartheasy.com/wear_ecospun.htm
- ^ http://www.innovations-report.com/html/reports/environment_sciences/report-7183.html
- ^ http://www.thisisbrandx.com/2009/11/trashy-chic-recycled-clothing-from-playback.html
- ^ http://www.innovations-report.com/html/reports/environment_sciences/report-7183.html
- ^ http://www.rewarestore.com/tech_recycled_pet.html
- ^ http://www.sustainableisgood.com/products/2008/04/billabong.html
- ^ http://www.innovations-report.com/html/reports/environment_sciences/report-7183.html
- ^ http://www.billabongbiz.com/bethechange/environment.php?page=sustainable
- ^ http://www.billabongbiz.com/bethechange/environment.php?page=sustainable
- ^ http://www.treehugger.com/files/2008/03/rip-tide-livity.php
- ^ http://www.eartheasy.com/wear_ecospun.htm
- ^ http://www.rewarestore.com/tech_recycled_pet.html
- ^ http://www.gogreenstreet.com/eco-friendly-recycled-plastic-bottle-board-shorts/
- ^ http://www.thisisbrandx.com/2009/11/trashy-chic-recycled-clothing-from-playback.html
- ^ http://www.allbusiness.com/consumer-products/office-supplies-equipment/6916130-1.html
- ^ Plastic
trial procedure Oaktech Environmental website, accessed 9.11.06
- ^ Agricultural
plastics recycling process Agricultural plastics recycling website,
accessed 07.11.08
- ^ Plastic
Composite Railroad Tie Facts Plastic Composite Railroad Ties website,
accessed 01.21.08
- ^ Recycling
Used Agricultural Plastics James W. Garthe, Paula D. Kowal, PennState
University, Agricultural and Biological Engineering
- ^ Page, Candace, Waste district raises recycling fees, Burlington
Free Press, November 12, 2008
- ^ Financial Times, May 15, 2009 (article by Max Hogg)
- ^ The Self-Sufficiency Handbook: A Complete Guide to
Greener Living by Alan Bridgewater pg. 62--Skyhorse Publishing Inc., 2007 ISBN
1602391637, 9781602391635
- ^ "Where
can we put all those plastics?". Seattle Times. http://seattletimes.nwsource.com/html/homegarden/2003730398_ecoconsumer02.html.
Retrieved 2007-06-02.
- ^ Where can we put all those plastics? By Tom Watson
June 2, 2007 Seattle Times http://seattletimes.nwsource.com/html/homegarden/2003730398_ecoconsumer02.html
- ^ Recycling FAQ by Ginny Figlar http://life.gaiam.com/gaiam/p/Recycling-FAQ.html
- ^ Plastics
wasteonline.org.uk, Accessed 10.18.07
- ^ "Safe
Use Of Plastic Food Packaging And Containers". http://www.ava.gov.sg/FoodSector/FoodSafetyEducation/Food+Facts/SafeUsePlasticContainers/index.htm.
- ^ "19". Holt Chemistry (Florida
edition). Holt, Rinehart, and Winston. 2006.
p. 702. ISBN 0-03-039114-8. "More
than hlf the states in the United States have enacted laws that require
plastic products to be labeled with numerical codes that identify the type
of plastic used in them."
[edit] External links
- West, Larry. "Recyclable
Plastic: Why are So Few Food Containers Made of Recyclable Plastic?".
About.com. http://environment.about.com/od/reducingwaste/a/corn_plastic.htm.
Retrieved 2009-05-04.
- Plastic
Packaging Resin Codes data from the American Chemistry Council
- ISF's Plastics
Recovery Manual
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