Polyformer: An open-source machine, recycling bottles into 3D printing filament
dezeen.comat the intersection of "sounds like a good idea" and "reality has entered the chat" since I'm guessing the input bottles have to be scrubbed completely clean of glue and any foodstuffs therein before being fed into the heating element
and since the article's hyperlink to "open source" is blatantly misleading in that context, here's the goods: https://github.com/Reiten966/Polyformer