Dave Hakkens of the Netherlands has designed a mini recycling ... how to build each machine. Blueprints and videos are free to the public. The project is called Precious Plastic.
As a proof of concept, it seems as though this machine was made from repurposed plastic, but it could also be made using whatever filament you happen to have on hand. As far as recycling goes ...
and their open-source plans for small-scale plastic recycling machines have come a long way since then. They currently include a shredder, a compression molder, an injection molder, and a filament ...