Hi there, does anyone know what’s the name of any transparent plastic sheets (1mm) that can be used for vacuum forming? I dont think Polypropylene comes in clear does it?Thanks…
butyrate
best transparent sheet for vacuum forming - Vivak (tradename for PETG formulation) can be obtained from Ain Plastics
Another product that is used in radio control car bodies is Lexan. Do a Google search using that name.
Otis52
pcg motorsports
Polycarbonates, (like Lexan) are a little more viscous when Vac-formed, and must be formed at higher temperatures (longer in the heater), but have the advantage of being pretty much indestructable once formed. It can be tacked together with solvent, but you really need some kind of mechanical connection for it. Butyrate (like Vivak) forms complex shapes really well and can solvent weld, but it’s not that strong once formed. McMaster has some film that matches your specs:
we used acrylic at school.
we use Vivak at work (Sign for stores)
Polypropylene doesn’t come in clear, but comes in VERY close to clear. Not sire of the grade # but that’s what i’ve heard.
Check out www.azom.com
Poly carb is a great material once it’s formed. It’s more expensive because of the higer heat needed like dmuren said. But also because it needs to be dried and this is a pain. Acrylic works very well. It’s kind of brittle though.
Mark
I believe you can use clear styrene as well. But just plain old acrylic works well too.
I’m pretty sure styrene and acrylic are the same thing. Just like acetal and delrine. Confusing business plastics.
Wrong. They are very different materials.
Styrene is short for polystyrene (PS), acrylic is polymethylmethacrylate (PMMA). Yes, both can be thermoformed, but please don’t confuse one with the other.
Both are amorphous commodity resins, but you see acrylic used in low-cost optical applications like clear containers, POP dispalys, or windows. But it doesn’t do well with UV and has poor chemical resistance.
Styrene, or the family of syrenics are used all over the place. But be careful of their poor impact strength and poor performance in UV and higher temps.
Do a quick search for acrylic and styrene and you’ll find all sorts of accurate information.
Please be careful what you post on this board.
Thanks,
Warren
I thought I heard it from my molder. I clarified it with him and it is indeed at the time the music must have been too loud. I was wrong. One thing I think is interesting is they both have similar properties: transparent and brittle, but I only hear about acrylic in sheet form and styrene as an injection molded plastic.
It would be nice to have a little further clarification on this fact.
One of the most common, everyday applications of thermoformed styrene sheet is coffee cup lids. You can find styrene sheet all over the place. I like it for model building because you can get it at a hobby store in all sorts of thicknesses and build things using CA (super glue) or methylene chloride (to solvent bond).
Most like using acrylic for its clarity - when it’s clear it’s glass-clear. It’s hard, and rigid, glossy and has good weather resistance. You see it used for signs, inspection windows, tail light lenses, lighting diffusers, leaflet dispensers and dust covers. It’s great for thermoforming. It’s also a little denser than styrene, so it’s a bit heavier. Also, while stiffer than styrene, it’s also more brittle. By the way, you can get cast acrylic sheet and extruded acrylic sheet - they have different properties.
Styrene is a real commodity resin. At most thermoformers, you’re more likely to see high impact styrene, an alloy of styrene and butadiene. As for clarity, you can get optically clear grades, by you’re mostly talking about translucent. One bonus for styrene is its recyclability.
You really should talk to a molder regarding your application to help you decide which is more appropriate.
Cheers,
Warren
Acrylic, ABS, Perspex
I think Warren’s got you covered for the most part. But, I’ll just put in a last little two cents:
Acrylic is popular for thermoformed sign fronts and lots of other applications, mostly because of it’s low cost, and transparency. But, if you are trying to get it to conform really well to a mold, its elasticity will probably make you crazy. Acrylic doesn’t drape nearly as well as styrene until you heat it up really hot, and then you run the risk of forming bubbles in the sheet, which can really crap up your final piece.
Also, Acrylic is pretty susceptible to being weakened by certain solvents. For instance, if you use isopropyl alchohol to de-bond hot glue for jig setups and things, don’t use it on acrylic. It can increase the brittleness of the plastic to the point where stress cracks form, and your part just breaks. It’s definitely not a fun time.
Vivak is much better at draping, so you can get much finer details out of it.
Polycarbonate drapes even worse than acrylic, but it’s super strong when it’s done. Unfortuntely, it’s pretty expensive.
Your best bet is to look at the specific application that you’re using the plastic for. Most times, for school or presentation models, acrylic or vivak will be fine. You’ll only have to go to the more expensive, more crazy stuff when you need specific strength or chemical resistance.
Acrylic can very well be used for short term/ornamental purpose. Advantages are easy availability, workability and optical properties. Good for mock-ups/exhitibions.
PS is good but in clear form it is difficult to work, should be injection molded.
If even little functional properties are required, its better to use PC, but theres lot of hard work!!