On Thu, 13 Mar 2008 21:56:41 -0700 (PDT), wrote:

On Mar 13, 11:27*am, Randy wrote:
Any plastic guru's here?

Looking to replace a peice of 3/4" plywood with some type of plastic.
Application is in a heated press used to join rubber sheets. *Problem
with the plywood is it compresses in use, and as it gets thinner the
bolts used to hold the whole thing together start to stick out and the
unit requires frequent retorquing.

Need some type of plastic that does not compress like wood, can
withstand 350 deg F for 1 hour, and idealy would have a coeffient of
expansion close to aluminum.

Gargolite G7 looked nice until I saw the price of a 2 x 3 foot peice
at $1140.00. I would need 2 x 4 or 5 foot peices.

Any suggestions.

Thank You,
Randy

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Was the plywood you were using just regular fir or hardwood stuff?
They do make a phenolic-clad Baltic birch plyboard for steel-rule
press work. This stuff is about as stout a stuff as you can get in a
wood product, it's used in a hydraulic press with a urethane die
blanket opposing it for sheetmetal forming. Not sure how it would
stand up to heat, though. Expensive stuff, too, last chunk I bought
was 2x3 and ran about $40. You aren't going to get it from the local
Lowe's or Home Despot, either. Strictly an industrial material, may
take a little searching in your area to find it, called die-board
around here. Cheaper than your Gargolite, though.

Stan

Stan,
That might be something, This is for a customer and I'm sure they
were using Home Depot plywood.

The material has to be a thermal insulator as this sheet goes between
the heater plate and another sheet of alum., and somewhere in there
is an airbag to provide the force and some alum I-beams and tie bolts
to clamp the whole thing together. The airbags need the wood sheet
to limit the amount of heat they see.

I'll need to research the thermal conductivity of wood VS particle
board VS Al honeycomb.

Wafer wood or particle board are pre compressed in their manufacture
so that might be better, or the die-board or some other premium
plywood might be better.

Where would one look to buy die-board?

Thank You,
Randy

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