www.TK560.com

[vacman]

Hi, I'm new to vacuum forming as I am sure many here are. I am in the process of finishing up my first machine. The machine I made has a 20x20 inch forming surface.

Here is what I'm trying to do:

My mold that I want to form is roughly 10x12x4 inches. It is basically the shape of a book. I will use it to make 2 final 'shapes'. The first having the mold laying down flat, horizontally. The second having the mold laying down on its side where it is 10 inches tall, 12 inches wide, and 4 inches thick.

My question is about Styrene thickness. I want to achieve an end product thickness that is about equal to a remote control car body. Nothing thick and heavy, just something that holds its shape and is somewhat durable. I will be using clear Styrene (if that makes any difference).

For the first shape, the flat horizontal one, what thickness Styrene should I use to achieve my desired end thickness?

For the second vertical shape, what thickness should I attempt it with? I'm sure it will have to be considerably thicker because it will need to stretch more correct?

Any input anyone can give me is greatly appreciated, even if you can just offer advice or tips.

Thank you for your time.

[jegner]

Good questions. When I'm doing my deeper pulls, like the RFT helmet dome, I use .093 HIPS. 90% of the rest of my stuff, I use .080 thick. That seems to be the best general purpose for my needs. My suggestion is to get some .080 and do a pull. It's cheaper that the thicker materials and will tell you all you need to know.

As for clear styrene, I've not see or use it, but have used PETG in .093 with good results.


Jim

[vacman]

Thank you for the reply.

I guess I will order a few different thicknesses and see which ones will work best for what I need, but at least now I know a thickness range to play with.

I found a few places that cell clear Styrene here up in Canada, prices are reasonable, but there are quantity discounts. I'm going to have to phone around to see if there is a minimum order size.

When you ordered your sheets, did they have order limits? Were you able to purchase just a few sheets? Also, how did they ship it to you, 48x96 sheets seem damn big to ship.

Thanks.

[jegner]

You can order the full sheets 48x96 inches, but you are correct, big and hard to work with. Most places will trim to your holding frame sizes, if your frames can be cut evenly down into standard sheet sizes. Example, 48x96 can be cut down to eight 24x24 panels. Economy of scale.

Most places will trim for free. But have a minum dollar amount. $30 is the norm. That equals to 1 sheet.

Jim

[vacman]

PETG is what I was thinking off not Styrene, sorry.

For some reason I thought they were the same, until my last google search 2 minutes ago.

How does PETG compare to Styrene cost wise? and durability wise? I need a cost effective clear plastic, are there better choices?

All the websites selling plastic sheets online require you to phone and ask for a quote, something I will have to do tomorrow since it's Sunday.

Thanks.

[jegner]

Look at www.professionalplastics.com

You can order online, if in the US, other countries, I'm not sure.

PETG is one of the hardest clear vac-forming plastics around. Much stronger than Acrylic or lexan. Not as brittle and more impact resistant. About as easy to form as ABS. Cost, about twice that of HIPS.

Jim

[drcrash]

Clear styrene is very brittle.

(The stuff they put in styrene to make it high-impact styrene is not clear, unless there's something new I don't know about.)

PETG is much tougher and easy to form. It's a bit on the soft side, but very fracture-resistant.

Acrylic (like Plexiglas or Perspex) is stronger than PETG, but because of its rigidity it's more brittle. It's also a bit harder to form.

Polycarbonate (like Lexan) is very strong and difficult to break, but still harder to form.

Acrylic and polycarbonate are likely to need predrying if they're not fresh and with moisture-retarding film on both sides, and/or if you live in a humid environment.
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Paul (a.k.a. Dr. Crash)

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[vacman]

I was looking at Vivak branded PETG, supposedly it is made ideally for vacuum forming. Do you guys have experience with Vivak? Is there a noticeable difference between it and regular PETG?

Thanks.

[cod]

I would think that Vivak is just a brand name. I haven't thought about brands so much and just went with whatever pet-g I could find .
The only thing you migh t look for is thickness and whether it's UV stabilized, if it's going to get a lot of sun. I believe some brands add an UV stabilizing layer.
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[cod]