Re: Polystyrene

[Elizabeth Nevers <enevers@facstaff.wisc.edu>]

At 09:36 AM 1/9/98 -0500, you wrote:
>
>Staff in our recycling division are doing some research regarding
>polystyrene.  Can anyone tell me the chemical makeup of polystyrene and the
>cost per pound to produce?
>
>Thanks for your help.
>
Annette

I did my grad school research on  the economics of post-consumer polystyrene
recycling but that 's five  years back.  I don't have my thesis in this
office but here's what I can dreg out of the  "remote storage" area  of my
brain.. 

Polystryrene is one of the primary "commodity" plastics.  It's cheap and can
be used for a lot of things.  Most people recognize it as 'styrofoam" which
is usually around 95% air.  But it's used in lots of other packaging where
it can be clear or opaque...from blister packs to plastic wine glasses to cd
jewel boxes and more. 

As I recall, the styrene monomer is carbon and hydrogen with benzene rings
attached to the carbon.  But a wide range of additives can be used to create
the particular qualities that are wanted.  So you probably want to know what
kinds of PS you plan to recycle.. Also are you looking at post-consumer or
post-industrial.  Most plastics facilities do practice a lot of in house
recycling.  Post-consumer is much harder (economically) to recycle because
of the collection and processing costs combined with the fact that it is a
very cheap virgin resin to begin with.  There have been various attempts by
the PS plastics industry to recycle post-consumer PS but it's pretty darned
expensive.  (Or at least it was five years ago.)Technically it's not more
difficult to reprocess than any other of the primary commodity plastics. 

AS I have been out of the plastics recycling field for five years, I suggest
so you  contact one of the  trade organizations like the Council for Solid
Waste Solution which should be able to answer  your questions and provide
more up to date info.

For virgin resin prices check out Modern Plastics magazine or contact a
primary PS resin producers like Amoco.

ANd for your Friday trivia:  The first large scale use of styrofoam was
during WWII in anti-submarine nets.  The metal floats  where filled with PS
foam and then would not sink even if riddle by enemy machine gun fire.  ANd
remember when McDonald's dropped their PS clamshell because of consumer
protest?  Well,McDonalds   developed the clamshell  in response to earlier
consumer concern about the trees being used in their original wrapper.
Environmental issues keep recycling too!



        ================================== 
         Liz Nevers
         Nat'l Farm*A*Syst / Home*A*Syst Programs			          
         B142 Steenbock Library		            	 
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         Email:  enevers@facstaff. wisc.edu			 
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