Plastic (not so) fantastic

Disclaimer: This is a bad idea, don't do this (and if you do, don't blame me for your subsequent respiratory issues)

Still mourning the 'loss' of epoxy, I've been looking around for alternatives. Somewhere along the line, I got the idea of seeing if I could recycle plastic into some form of fairly clear, hard, epoxy alternative. I did some research, and the general consensus was that this is a bad idea as many plastics don't melt, they degrade, giving off toxic fumes in the process...

However, never one to be deterred by common sense, I pushed on... It seems that Polyethylene terephthalate (PET) and Polypropylene (PP) are two of the safer plastics to melt. PET is by far the most common, so I settled on that. After collecting food containers marked with the PET recycling symbol, I discovered that there are further nuances to this - namely 'A-PET' and 'R-PET'. These are sub-types of PET, and while most things are just marked 'PET', they are useful because 'A-PET' is probably better than average, and 'R-PET' is probably worse... 'A-PET' is amorphous PET, which means it's less likely to crystallise and go white (see below). 'R-PET' is recycled PET, which means it's been through the ordeal once already and is less likely to go through it well a second time.

I found an old saucepan (Carolyn used to cook amazingly, I barely manage to cook at all, so there are lots of saucepans looking for a new career), and 'shredded' the PET containers into it as best I could. I started heating over a vigorous heat (I'm a vigorous kinda guy), with the window open and my daughter at school as vague nods to safety.

The PET began to turn white, without even starting to melt. I think this is because the PET is crystallising - the disorganised polymer chains are unionising and that turns the solid white. I decided to add a saucepan lid, and lower the heat. The good news was that the PET did start to melt and even turned clear, the bad news was:

• It turned white again when it cooled
• A lot of containers yielded a very small amount of liquid
• The molten PET is really viscous, making it very hard to work with (think cold honey)
• The molten PET solidifies almost as soon as the heat is removed, making it basically impossible to pour
• The solidified PET was very very sticky and almost impossible to remove from surfaces

The good news was that it was really hard once set, but also brittle, further suggesting it had crystallised.

I had a second attempt using even lower heat and the saucepan lid from the start, but with the same outcome:

The resulting 'vomit' of plastic is kinda cool, and so I did some experiments with it in GIMP and Blender:

However, overall, this hasn't been a huge success! I think I will try one more time using only PET bottles (which I'm hoping are better quality PET than the vegetable cartons) and if that doesn't work, I'll go back to putting my PET in the recycling like a good citizen.