I recently picked up a garden shredder on ebay for 15€ in the hopes I can misuse it for shredding plastics. This should then be fed to my Filament Factory to create 3D printer filament.
The Einhell EGC 2400 has a 2400 Watt motor. Plenty of power to shred branches and plastics. I went with Polypropylen flower pots. At my local florist I asked for those old pots and got a whole load of the precious resource.
I made some pictures and a video of the outcome. The shredder had no problems processing the pots but the pieces are still too big even after shredding them twice. See for yourself.
Won’t the blades get damaged if you shred plastic with it?
The plastic is rather thin. You can easily rip it with bare hands. Generally cutting plastic will make the blades dull but they can easily be dismounted and sharpened again.