(worth noting that these pullstruders are all separate from the methods of shredding or grinding plastics into granules/pellets and using an extruder, i.e. https://www.youtube.com/watch?v=nQ0UyWKafAw, whose videos on the subject are good overviews of the process but tend to annoy me because they use pretty hobby-accessible tools for everything but the critical grinding part, for which he wheels out a sponsor's $10,000 commercial plastic grinder)