what's the best way to mould 2Ltr plastic milk bottles into any shape??

I'm trying to mould plastic milk bottles (pieces of) into a shape onto a mannequin..... for a comp...... i'm making an outfit.... and to mould to a body shape (curves)

Gorfram7 years ago
Milk bottles are usually the kind of plastic with a "2" in the little recycling triangle, also known as High Density Polyethylene or HDPE. HDPE gets much easier to work with above about 170 F (75 C), and melts over a range from 250 to 265 F (120 to 130 C). Unless you want to actually melt and re-cast it, you'll want to try to work with it in between those two temperatures. If you can immerse it in boiling water, that will take it to and keep it at 212 F (100 C). If course, then you'll have boiling hot water to deal with along with the very hot plastic. Otherwise, you could use a heat gun (which is basically a hair dryer hopped up to reach way-above-hair-heat temperatures) or some other heating device. You may run into some shrinkage problems - many plastics shrink when heated to near their melt temp, and often curve or curl up as they do. I've been "shrinky-dinking" various plastics in the oven for a project I'm doing. With HDPE, I seem to be getting nothing at all at lower temps, and then 20-30% shinkage and mild curving at right around 210-220 F (my oven turns out not to be a precise scientific instrument, I'm afraid :). But different manufacuters use slightly different plastic "recipes", so YPMV (Your Plastic May Vary). Godd luck - I'd love to hear how it turns out! :)
antheajane (author)  Gorfram7 years ago
Thanks for getting back to me with some solutions. Much appreciated I tried the boiling water idea and it worked. I boiled a large pot of water and put each piece of plastic in as I required it, then I moulded it onto my mannequin in the position required and held it into place with weights then let it cool naturally by itself. Thanks again for your help. Great help.....
Whoo-hoo! I'm glad it worked, and glad my answer helped. Thanks for letting me know. :)