|Originally posted by KFung:
Anyways Kydex would seem like the best option of the plastics they offer on that page, mostly because of its excellent formability when heated. Acrylic and PVC are both thermoplasts so you should be able to heat them and form them. With proper support you could have a Torus CCS-type screen with no elaborate vacuum system! WOW! The hard part would be heating and custom forming such a large surface...
This is where my original comments on 'vacuum based' - plastic bag molding systems comes back into play, for the manufacture of the FORMING MOLDS, for the heat curing of the shape, into the plactic. You should be able to use the inflated bag, on a square box, that has a shaping of theouter four pieces, that will automaticlly infer the proper shape to an inflated bag..
Using the proper high grade materials for the inflated bag, and usig HOT AIR, in an agitated way, will cause the 'inner plastic screen, to form to the desired shape, due to the fact that it will press hardest upon the parts of the bag that are not conforming to the desired shape. The heat transfer will be the greatest at this point, thus the plastic will heat up most there,and become pliable, and then bend to th underlyng hard mold shape.
parhaps, all that is needed is the blown up, shaped bag, with agitated heated air flow, and the screen plastic dropped straight on it, above it. Pressure works against gravity, and btween the two, the desired shape is created,and the bag is then filled with cooler air, thus solidifying the screen into the impressed shape.
There is no reason, why this should not work PERFECTLY, ater a few trial runs have been made.
The biggest problem, is the mathematical transfer of the curvature desired WITHIN THE SCREEN, to the CURVED, FLAT sides of the 'pressurized-air-bag-mold'. THe desired pressure is reached to describe the flatness of the inner part for the problems associated thru the use of CRT's, and the multiple seating positions.
The math is straightforward, and it only has to be done once. The mold can be experimentally manufactured on a small scale in a few hours, using some cardboard, some tape, a garbage bage, and a vaccuum's reverse flow (air exit) to prove the validity of the 'hot-air-bag' molding approach.
For those with a sense of humor, it can be noted that all that is needed, is a blow-hard, a garbage bag and some duct tape... and a box to put the mess in.
For those of you who are having a hard time visualizing exactly what I am getting at, recall the appearance of a pressurized, inflated dome tent building, like a indoor tennis court, or a indoor soccer field. You drop the pre-perfoated flat, rectangular screen material on top, and let the heated air in the 'tent' do it's job, along with gravity, then substitute with cold air in the tent for hardening.
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[This message has been edited by KBK (edited 10-04-2000).]