PIG SIG Plastic recycling?

[mrcity]

I’ve seen some videos on taking HDPE plastic (♴), melting them down, and turning them into things like cutting boards etc. I’m thinking of taking used bottle caps, milk cartons, etc. and turn it into sheets to be used in the vacuum form.

Is it feasible to vacuum form HDPE with the one we’ve got?

Would it make for decent quality parts that are fairly durable?

Would we want to set up some sort of “community HDPE free shelf”?

My waste stream seems to have a lot more PET/PETE (♳) but from what I’ve seen, you have to shred it into small pieces in order to reform it, right?

[nicksilva]

hello. I suppose the answer lies in how thin you can make the sheet.
For the vacuum former most of the sheets used are in the 0.050" and less. The former heats to about 300 degrees or less which is enough to soften the plastic for stretching. HDPE has a working temp of about 220 and Polypropylene has a melting temp of 330 degrees so there is definately enough temp to make it soft and stretchy. The magic is the amount of stretch you can get out of it which lessens inversely to the thickness.