[Nickk6]

Hi there, I am not sure on where to post my question, I've searched the forum but was not able to find anything on how to Vacuum Form Polycarbonate. I have some .060 polycarb and wanted to know the following information:

How hot does the mold need to stay and what is the recommended temperature to heat the plastic?

Thanks in Advance

[Geof]

This is a thread discussing bending polycarbonate.

http://www.cnczone.com/forums/showthread.php?t=17444

And it has this link to information about other ways of working with polycarbonate.

http://bildz.altronix.se/mekpro/9030.pdf

The most important things with heat forming polycarbonate are the preheat, or prebake to dry away the adsorbed water on the surface and careful temperature control.

[Nickk6]

Thank you for the quick reply. Do you know an easy way to dry the polycarbonate? Is there a heat lamp that will work or do I need to oven bake it.

The polycarbonate is on a roll.

[One of Many]

Thank you for the quick reply. Do you know an easy way to dry the polycarbonate? Is there a heat lamp that will work or do I need to oven bake it.

The polycarbonate is on a roll.

We had a heated locker that kept it at 150def F for up to a week. .06 shouldn't take that long, but if you see bubble appear when forming, it still has moisture in it. Cut it into blanks for drying, otherwise it may take a set if dried as a roll.

The tool should be hot. Maybe up to 280. Onced PC is formed, don't let it cool too long if there is little draft in your tool. That makes it harder to get off, since PC seems to shrink pretty fast. Air eject helps too. We just used fans for the cooling cycle. Never did have water cooling. Do not let the fan run and cool the tool between parts. Once the tool is up to temp, keep it there, even if you must use a heat gun. For the most part, the next forming blank should keep the tool hot, but delays between parts don't help that.

DC

[Geof]

Heat lamp is very unlikely to work. The important thing is holding it at the temperature for quite a while; maybe not a week but certainly a few hours.

[One of Many]

Heat lamp is very unlikely to work. The important thing is holding it at the temperature for quite a while; maybe not a week but certainly a few hours.

Our minimum was 3-4 days on any hygroscopic incoming stock prior to forming unless it was dated within a week of extrusion. The locker was 12' x12' x 8' tall. Some of it just took a lot longer to dry out. Don't know if it was old stock, made on a humid day or stored outside. We formed roughly 15 tons of PC per year. Anywhere from .03-.375. I'd guestimate over 120 tons in other materials between ABS, POLY, STYRENE, PETG, PVC and a few others that slip my memory.

The only real way to tell is go ahead and form it and check if bubbles develop from boiling moisture. Any evidence pulled the job and went back to the locker for another 24hrs or when the filler run was finished.

Seems to me there was some 1/8 or 3/16 that was in the dryer for several weeks and never would dry out totally. We finally started using it for preheating the dies up to temp each morning.

DC

[bpmufx]

Question: What is your Buck made of? If it's any kind of gypsum material, it also needs to be baked dry. If not the steam produced when pulling will affect the surface quality.