How to Make Your Own Prototypes : How to make your own Plastic Vacuum Former

Step 12 Closing Thoughts

Large plastic sheets are available online from many suppliers. Check out the United States Plastic Corp. for material, or be creative and use things around the house. If you find anything good to use that's freely available, please add a comment for others to use in their projects.

When you are finished with the plastic mold, you can fill it with either fiberglass resin or Alumilite to get an exact copy of your original object.

Comments

[Valpara]

I'm not sure if this is the correct plastic, but what about the thin cutting sheets used for chopping veggies and such? It seems like the perfect size. Obviously, you can buy the clear/opaque ones, but there's also different colors, which might be beneficial to some prototypes.

I don't what they use to add the coloring... not sure if it would cause any problems. Anyways, just a suggestion because they're cheap and easy to find. The attached image shows what I'm referring too. They're 0.2" thick: 1. Flexible Cutting Board 2 Pack (12" x 18") - $3.99 on webstaurantstore.
2. MIU Flexible Cutting Board, Set of 5 (11"x15") - $9.99 on Amazon.

I was also thinking of laminating sheets, but I think they'd be too thin and stretch to the point of tearing. I'll let you know the results I get if I try either of them. Great Instructions though, thanks!

[mechcem]

Type 6 plastic is the most effective and stable medium for this. Others probably could work, you should just be careful and look up there melting points and toxin release rate for them

[InventiDan]

Go to Lowes, Home Depot or any Hardware and get Acrylic sheets. They are sold anywhere PlexiGlass is sold. IE: Storm doors and windows. There is acrylic and poly.... something sheets. sorry I forget the exact name of the poly sheets, But I have used the Acrylic sheets and they work great and are sold in many different thickness. So if you have something tall to do, you wont strech it too thin. And as for heating it, Use your oven set for 350 to 400 for 3 to 4 minutes. Hope this helps.

[IcedZ]

Polycarbonate

[thalden]

The lining on the boxes that cooking grease comes in are HDPE. Ask your local restaurant if they can save you one. You get about a foot and a half square of flat plastic off each side, if not more.

[katita]

thank you very much for your free site...i really hope this helps me creat a prototype for my invention...my question is i am looking for a soft non degradable plastic for medical ..use... or where i can go or see plastic samples..use. thanks again

[sheekgeek]

I'm really not sure where you can find medical grade plastic. The best idea I can think of is to make some prototypes yourself to get the shapes the way you want, then go to a company that will help you with manufacturing such as Enventys. http://www.enventys.com/ or IDEO http://www.ideo.com/ They have the experience required to help design, fabricate, and manufacture medical devices that can be implantable.

[katita]

thank you sheekgreek..i will note these ideas and follow up...i must get this product on the market asap...

[bobtannica]

Milk (and water) jugs in the USA are made of HDPE. My first question is how hot should the oven be preheated to? Question number the next is how does one "plastic weld" HDPE? Thanks. Great Instructable!

[snowpenguin]

There is no oven involved. A heat gun is used.

[jensenks]

A thought on the larger model - a common picnic cooler is already airtight and comes with it's vacuum hookup already in place (the water drain). All that would be left is to secure that perforated top. Thanks so much for taking the time to post this! I really enjoyed it!

[michaelb1]

I wonder if this would work with PET plastic water or soda bottles. Has anyone tried to melt those in an over and use it for the plastic sheet?

[Goedjn]

PET is pretty much unworkable in a home shop environment. I suspect it's because it sucks up water from the atmosphere, and you have to drive all that excess water out of the plastic before you try forming it. Bottle-caps seem to polypropelene, (I mean, they feel right, and melt at the right temp.) which works pretty well for injection/compression molding, but since the gasketts are something else (ldpe?) it's hard to get a clean enough sample to to blow or vacuum form. --Goedjn

[Macyoshary]

I've found that HDPE which is the milk plastic works best. I cut up the bottles and plastic weld them together to form larger sheets.

[Scurge]

isn't that the same kinda plastic used to make the opaque gallon milk jugs? can you use those or are they too thin?

[roosta]

yeah, im fairly sure it is the same stuff. in the uk (dunno if you are) we get all our milk in white plastic milk bottles. unless your posh, in which case you get it in glass...

[Alan the Great]

I'm assuming you're talking about these? BTW, this is from Canada, but I think the rest of the world gets it this way too.

[wirah]

Yes but much, much smaller. The biggest we have is six pints. It is absolutely impossible to get milk in a container that large in the uk!

[Prop]

I get all my milk in bags (Canada)

[sysadmn]

I think those are called "udders". :-)

[redrobin]

I usally heat the plastic in a an old toaster oven, I found at a garage sale a few years ago, most of my projects are small and fit without any problem. Also sysadmn in Canada you can buy milk in plastic bags,there is also a plactic pitcher to put the bag into."Only in Canada you say!"

[FranceLab]

You could cut a milk jug along the side and straighten/flatten it out to get the whole surface area, then you could warm it up and press it so it will turn into a flat, usable, large piece.