I remember back in the early 70s as plastics where really coming into common
usage for everything there was a panic about them lasting forever.

Then in the 80s everything plastic was basically considered to be very short
term life (in terms of the human lifespan). I had heard that most (all?)
plastics had been modified to make them break down.

Why can't we get those "good" plastics from the 70s anymore, and did they
ever really exist or was it all a big scare tactic?

On Feb 4, 10:24*am, "Bob La Londe" wrote:
I remember back in the early 70s as plastics where really coming into common
usage for everything there was a panic about them lasting forever.

Then in the 80s everything plastic was basically considered to be very short
term life (in terms of the human lifespan). *I had heard that most (all?)
plastics had been modified to make them break down.

Why can't we get those "good" plastics from the 70s anymore, and did they
ever really exist or was it all a big scare tactic?

Apparently they never existed. Science News had a good article in
November about this very subject, and discusses the measures that some
museums are taking to try to preserve the plastics in their
collections.

http://www.sciencenews.org/view/feat..._Live_Plastics

On Feb 4, 1:24*pm, "Bob La Londe" wrote:
I remember back in the early 70s as plastics where really coming into common
usage for everything there was a panic about them lasting forever.

Sunlight breaks most of them down, unless they are buried in a
landfill.

jw

On Wed, 4 Feb 2009 11:24:18 -0700, "Bob La Londe"
wrote:

I remember back in the early 70s as plastics where really coming into common
usage for everything there was a panic about them lasting forever.

Then in the 80s everything plastic was basically considered to be very short
term life (in terms of the human lifespan). I had heard that most (all?)
plastics had been modified to make them break down.

Why can't we get those "good" plastics from the 70s anymore, and did they
ever really exist or was it all a big scare tactic?


There's a big difference between the point where a plastic part is
degraded to the point where it no longer functions as was intended,
and the time when it can be indiscriminately discarded.

A sun-damaged plastic bag isn't much use for carrying stuff, but you
wouldn't flush it down the toilet.

--
Ned Simmons

On Wed, 4 Feb 2009 11:24:18 -0700, "Bob La Londe"
wrote:

I remember back in the early 70s as plastics where really coming into common
usage for everything there was a panic about them lasting forever.

Then in the 80s everything plastic was basically considered to be very short
term life (in terms of the human lifespan). I had heard that most (all?)
plastics had been modified to make them break down.

Why can't we get those "good" plastics from the 70s anymore, and did they
ever really exist or was it all a big scare tactic?


Current leanings are that it is a huge problem (plastics not
really degrading). A couple of articles I found:

http://www.bestsyndication.com/?q=20...fic_oceans.htm

http://www.wired.com/science/discove.../2004/06/63699

I've heard/read several similar reports in the past year
(shrug).

--
Leon Fisk
Grand Rapids MI/Zone 5b
Remove no.spam for email

Bob La Londe wrote:
I remember back in the early 70s as plastics where really coming into
common usage for everything there was a panic about them lasting
forever.

Then in the 80s everything plastic was basically considered to be
very short term life (in terms of the human lifespan). I had heard
that most (all?) plastics had been modified to make them break down.

Why can't we get those "good" plastics from the 70s anymore, and did
they ever really exist or was it all a big scare tactic?

The "good" plastics are still around. They are
properly called engineering resins. Delrin aka
acetal, polycarbonates, teflon, nylon and acrylics
like plexiglass are still widely used in quality
products.

"Bob La Londe" wrote in message
...
I remember back in the early 70s as plastics where really coming into
common usage for everything there was a panic about them lasting forever.

Then in the 80s everything plastic was basically considered to be very
short term life (in terms of the human lifespan). I had heard that most
(all?) plastics had been modified to make them break down.

Why can't we get those "good" plastics from the 70s anymore, and did they
ever really exist or was it all a big scare tactic?

The plastics from the 70's and 80's is a big part of why it is tougher to
restore a car from that era. The parts are there but the sun has taken it's
toll.
Steve

In article , Jim Stewart
writes
Bob La Londe wrote:
I remember back in the early 70s as plastics where really coming into
common usage for everything there was a panic about them lasting
forever.

Then in the 80s everything plastic was basically considered to be
very short term life (in terms of the human lifespan). I had heard
that most (all?) plastics had been modified to make them break down.

Why can't we get those "good" plastics from the 70s anymore, and did
they ever really exist or was it all a big scare tactic?

The "good" plastics are still around. They are
properly called engineering resins. Delrin aka
acetal, polycarbonates, teflon, nylon and acrylics
like plexiglass are still widely used in quality
products.
Dunno about nylon; back in the late 60s I worked in a test house. We had
some nylon brake hoses for examination ( the curly airline between the
tractor and the body of a truck). UV exposure had made them as brittle
as a chocolate bar. So much for the good old stuff!
--
Chris Holford

Up North wrote:
"Bob La Londe" wrote in message
...
I remember back in the early 70s as plastics where really coming into
common usage for everything there was a panic about them lasting forever.

Then in the 80s everything plastic was basically considered to be very
short term life (in terms of the human lifespan). I had heard that most
(all?) plastics had been modified to make them break down.

Why can't we get those "good" plastics from the 70s anymore, and did they
ever really exist or was it all a big scare tactic?

The plastics from the 70's and 80's is a big part of why it is tougher to
restore a car from that era. The parts are there but the sun has taken it's
toll.
Steve


Plenty of Tufnol parts on my boats and friends boats that are still
going strong and 40 years young :-) Many of them are good for another
40 years too. You can still get phenolic composites that are just as
durable. OTOH there is a lot of plasticiser loaded cr@p out there in
consumer products which wont last a year of normal use. Rigidity seems
to go with durability. UV resistance is a whole other ball game.

--
Ian Malcolm. London, ENGLAND. (NEWSGROUP REPLY PREFERRED)
ianm[at]the[dash]malcolms[dot]freeserve[dot]co[dot]uk
[at]=@, [dash]=- & [dot]=. *Warning* HTML & 32K emails -- NUL:

Chris Holford wrote:
In article , Jim Stewart
writes
Bob La Londe wrote:
I remember back in the early 70s as plastics where really coming into
common usage for everything there was a panic about them lasting
forever.

Then in the 80s everything plastic was basically considered to be
very short term life (in terms of the human lifespan). I had heard
that most (all?) plastics had been modified to make them break down.

Why can't we get those "good" plastics from the 70s anymore, and did
they ever really exist or was it all a big scare tactic?
The "good" plastics are still around. They are
properly called engineering resins. Delrin aka
acetal, polycarbonates, teflon, nylon and acrylics
like plexiglass are still widely used in quality
products.
Dunno about nylon; back in the late 60s I worked in a test house. We had
some nylon brake hoses for examination ( the curly airline between the
tractor and the body of a truck). UV exposure had made them as brittle
as a chocolate bar. So much for the good old stuff!

I believe it. Nylon still works well for
internal parts though.

On Wed, 04 Feb 2009 11:24:18 -0700, Bob La Londe wrote:

I remember back in the early 70s as plastics where really coming into
common usage for everything there was a panic about them lasting
forever.

Then in the 80s everything plastic was basically considered to be very
short term life (in terms of the human lifespan). I had heard that most
(all?) plastics had been modified to make them break down.

Why can't we get those "good" plastics from the 70s anymore, and did
they ever really exist or was it all a big scare tactic?

I believe the basic principal is that if you want them to last forever
you keep them out in the oxygen and sun and changing temperature, which
makes them break down.

OTOH, if you want them to go away you bury them deep in a pile of
garbage, where there's no oxygen, no sun, and the temperature is
constant. There, with only some discoloration, they last forever.

--
http://www.wescottdesign.com

On Wed, 04 Feb 2009 20:34:12 -0600, Tim Wescott
wrote:

On Wed, 04 Feb 2009 11:24:18 -0700, Bob La Londe wrote:

I remember back in the early 70s as plastics where really coming into
common usage for everything there was a panic about them lasting
forever.

Then in the 80s everything plastic was basically considered to be very
short term life (in terms of the human lifespan). I had heard that most
(all?) plastics had been modified to make them break down.

Why can't we get those "good" plastics from the 70s anymore, and did
they ever really exist or was it all a big scare tactic?

I believe the basic principal is that if you want them to last forever
you keep them out in the oxygen and sun and changing temperature, which
makes them break down.

OTOH, if you want them to go away you bury them deep in a pile of
garbage, where there's no oxygen, no sun, and the temperature is
constant. There, with only some discoloration, they last forever.
My recycled washer fluid jug bins for good stuff are getting brittle
and cracking even without exposure to sunlight.
Gerry :-)}
London, Canada

Nylon, can be revived by boiling in water. The old nylon model airplane
propellers would regain flexibility after 20 minutes in boiling water.



Steve R.

On Wed, 04 Feb 2009 13:03:23 -0800, Jim Stewart
wrote:

Bob La Londe wrote:
I remember back in the early 70s as plastics where really coming into
common usage for everything there was a panic about them lasting
forever.

Then in the 80s everything plastic was basically considered to be
very short term life (in terms of the human lifespan). I had heard
that most (all?) plastics had been modified to make them break down.

Why can't we get those "good" plastics from the 70s anymore, and did
they ever really exist or was it all a big scare tactic?

The "good" plastics are still around. They are
properly called engineering resins. Delrin aka
acetal, polycarbonates, teflon, nylon and acrylics
like plexiglass are still widely used in quality
products.

They're better than ever. We now have things like LCP (liquid crystal
polymers) and other high performance plastics that will keep decent
mechanical properties at high temperatures. We have stuff like HIPS
that is incredible good compared to your Dad's polystyrene--
comparable to ABS or PC.

I don't think planned self-destruction is used anywhere but in
packaging materials (though packaging does consume a substantial
fraction of all plastics manufactured). IIRC, automotive is behind
both packaging and construction applications as a consumer of
plastics.

The plastics from the 70's and 80's is a big part of why it is tougher to
restore a car from that era. The parts are there but the sun has taken
it's toll.
Steve

About ten years ago I was working in a restoration shop on a 1904 Panhard,
and we were discussing which contemporary cars might be extremely valuable
in 80-90 years. We all agreed that plastics would be the killer, as you
would have to make molds and cast it from polymers or something. Now I can
see that "rapid prototyping" machines hold promise. Find the blueprint and
you solve the hardest problem.
My "valuable" car? The Yugo. There may be only one.
--
Stupendous Man,
Defender of Freedom, Advocate of Liberty