Shred Recycled Plastic Bottles

The goal is to shred recycled plastic from cups, bottles, and milk cartons in order to convert them into small pellets (or shreds or powder) that can then be melted into filament suitable for printing.

So far, I have not succeeded. If you try this though, you might learn from my failures.

First, I tried to cut a disposable plastic cup into several pieces. I used scissors to do it. So far, so good.

Next, I tried to shred the plastic strips in a paper shredder that supports shredding credit cards. That worked a little bit, but some of the pieces didn't come cleanly apart and the shredder jammed after just one cup. Shredding in a home shredder is probably harder than cutting the cup up by hand. Between the shredder and some hand trimming I got the size down to about 1/8“ by 1/2”. It was more work than I'd like though.

I tossed the smallish pieces into a coffee grinder hoping that it would grind them down even smaller. The coffee grinder, however, just tosses the pieces about. I ran it until the motor over heated and it refused to turn anymore. The pieces remained unchanged.