Acrylic Sheets forming

[Tandigon]

Does anyone of you in this forum have experience in forming Acrylic sheet. I need to form sheets that would be from a quarter inch thick to half an inch thick. Is there some kind of heating arrangement I can improvise to do this. The sheets could measure four by four feet. Is there some way I can protect the surface until I'm done. Any ideas are welcome and appreciated.

[Merlion]

My direct experience is limited.

Knowing the softening temperature is important. As you are forming plastic plates of such large size and thickness, perhaps a large enough oven is necessary, giving sufficiently uniforming temperature. (If you are just bending along a line, this is much easier, perhaps just two lines of heating elements.)

I think this softening temp will not char paper. So protecting the surfaces with thick paper may be good enough, unless the streching due to your forming pressing is not small as paper do not stretch. In the latter case, perhaps thin rubber sheets may offer surface protection. In both case, check it out first of course before your full-scale forming.

[obseq]

When you say 'forming' sheets, do you mean to say that you intend to permanently alter their shape?

I only ask because I, too, am trying to figure out a way to permanently form/mold/shape large, thin screens of resin or similar material.

[Arrow]

Just a wild idea. I wonder if a steam pressure washer would deliver enough heat....



"Adjustable temperature up to 250°F steam."

Quarter inch sheets may soften... but half a inch?? I have my doubts. Too much mass.

However without knowing the shapes your after, I don't know if it would be feasible.

[Merlion]

This involves heating the sheet from one side, and at a suitable temperature, sucking it with a vacuum from the other side over a mold.

The process is called vacuum forming, or thermoforming.

I think from a Google search, you can find information on it.

[toyholic]

vaccum-forming is a great process and pretty cheap to do for the most part. Here is the site I have created my table from . I haven't formed anything yet because I am still sculpting a few things.
The tables vary greatly but this one works and is a great budget table. they sculpt and build there own stormtrooper costumes and other things from Star Wars.
I'm working on a Legion of Doom headquarters from the superfriends to either vacuum form or silicone mold.

http://www.studiocreations.com/howto...ble/index.html

[WeiMingKai]

I am loving these boards! So many great things to discover.

That homemade vaccuforming table looks awesome! I haven't even considered vaccuforming as a possibility before - mentally relegating it to the realm of 'too industrial hence too expensive' where I keep all of my fever dreams of having access to massive machionery to aid me in noodling around in search of an interesting technique (instead of cranking out saleable practical products/components - which big machines usually do in order to justify having spent big money on them in the first place).

As I read the 'heating the plastic' instructions I am thinking that you don't want to do this with an oven you plan to use for anything other than plastic heating, one 'accident' and that oven will forever after exude a scorchy-burning plastic stink (unless you like the smell and taste of burnt plastic in your Tuna Casserole, or Turkey Dinner).

[toyholic]

yeah but if you where going to do it that way , you could hit a local thrift store and get an oven for hardley anything and set it up in your studio. I wouldn't use my home stove , but it's much cheaper and easier than building in a heating element into the table. I have seen plans for one ,but the cost was too much for my ideas.

[Daniel]

What kind of shape do you want to make the acrylic? There are other methods besides vacuum-forming. Vacuum-forming will pick up any imperfections on the surface of your mold and deteriorate the clarity.
There is also drape-forming in which a heated sheet of plastic is draped over a felt-covered wooden form. I made a couple of acrylic domes by cutting a circular opening out of a piece of plywood, installing an air nozzle setup under another board, clamping a heated sheet of acrylic between the two, and blowing in compressed air. The acrylic puffed up into a dome before it cooled.

You will have to remove the protective coating first, of course. There are spray-on masking liquids available to re-mask it afterwards.

[obseq]

Since some of you are mentioning materials such as acrylic/fiberglass/resin,
are there any suppliers available online that are recommended?

I've been scouring the net for such materials in sheet form, but can't seem to find a thing!

[Merlion]

Acrylic, and other thermoplastics like PVC, polythene and nylon soften whenever they are heated when being processed, and harden (stiffen) again on cooling. Building material suppliers (at least my local ones) stock and sell many of these in sheet form in standard 4 ft x 8 ft size.

I understand the common term 'fiberglass' means plastic resin embedded with glass fibers. Fiberglass sheets may not deform easily when heated (but others correct me if I am wrong).

In this Forum we have also mentioned polyester, epoxy, PU (polyurethane) and silicone. They are thermosetting plastics, which undego chemical change when being heated during processing, and cannot be reprocessed on being reheated.

But I think the softening temperature of acrylic is high and may not be a good material for vacuum forming. Polyethylene (PE, or polythene), polystylene (PS) and ABS may be better as they soften at lower temperatures, some types of these plastics even below water boiling temperature.

[Daniel]

Another thing, if you want to vacuum-form acrylic you might want to use clear PETG instead. It softens at a lower temperature than acrylic. I used it to vacuum-form some fairy wings and some other stuff. Worked great. Just remember that it will pick up all textures of the mold. I sucked the sheets down over carved urethane foam negatives of the wing shapes to get a kind of frosted glass look with the foam texture. The veins of the wings (dragonfly-like) I carved in deep so that the plastic never touched the mold there. That left transparent veins that looked great.

You probably can find suppliers online.

Styrene is great for vacuum-forming, but is opaque.

[obseq]

Tandigon,

Any progress in your pursuit?

I'd be really interested to read about anything you've discovered with acrylic or similar materials.

I've found a handful of plastics suppliers but noticed that they rarely post prices or images of their products.

[obseq]

I've been digging online around every day, and fell upon what seems to be a pretty comprehensive list of plastics brands and suppliers.

http://www.ides.com/generics/TPE/TPE_products.htm

[chatterx]

Originally Posted by obseq

I've been digging online around every day, and fell upon what seems to be a pretty comprehensive list of plastics brands and suppliers.

http://www.ides.com/generics/TPE/TPE_products.htm

Thats a hell of a find, I have added that to my favorites. Thanx a million... now I need about 12 hours to go throught that list LOL