Filament Pultrusion Machine
I’d been working with 3D printing for almost 3 years – building, custom modifying, and printing – when I decided to build a filament recycling machine. While filament isn’t prohibitively expensive, I was spending a fair amount of money on it and thought it might be more environmentally responsible and cost effective to create filament, myself, through recycling.
I learned about two main methods: (1) melting and extruding virgin plastic pellets; and, (2) pulling plastic strips through a heated nozzle. I chose to focus on the latter as I could recycle empty bottles, making it both cost-effective and environmentally friendly. One drawback of this method is that the recycled plastic may not have the same consistency and properties as virgin plastic and so it could affect the performance of the filament. Even if of lower quality, the filament could prove useful for a variety of purposes.
The device I designed and built uses soda, water, or other bottles of similar quality plastic and recycles them into usable 3D filament. It comprises a cutter mechanism to slice the plastic bottle into long, contiguous strips of plastic ribbon which is then fed through a heated nozzle. The nozzle softens and reshapes the plastic into 1.75mm cylindrical strings of filament which are then rolled onto a spool. This spool can then be placed onto and fed into a 3D printer to print new objects.
It is assembled from a mixture of recycled/repurposed components, salvaged scrap, and several custom parts I designed and printed using my 3D printer.