It’s no secret that waste is a serious problem in our modern world. Plastics are mostly made from non-renewable petroleum, and don’t break down well naturally. That means we’re consuming resources that are limited, and leaving behind permanent waste at the same time. Recycling is the best way to overcome that problem, but isn’t something most people can do themselves. Instead, we rely on recycling services. But this 3D printer design created by Sam Smith can print directly with trash plastic.
Smith has a lofty — yet achievable — goal of building a complete “Metabolizer” machine for recycling just about anything at home. But, on a smaller scale, he has developed a 3D printer than can use plastic waste as a building material. It works with both polypropylene (recycling #5) and HDPE (High-Density Polyethylene, recycling #2). Together, those two types of plastic account for more than 50% of plastic waste by volume. In order to make use of them, plastic trash is first shredded into chips using an open-source device called Precious Plastic that Smith designed back in 2016.
After shredding the plastic, the chips are loaded into a hopper on the 3D printer. They’re then forced down into an extruder, melted by a hot end, and deposited on a build plate just like how any other 3D printer would work. The design is completely open-source, so you can build your own. However, the extruder is quite heavy, which means you’ll want to use it with a gantry intended for CNC routing. It also prints at very low resolutions, and the quality isn’t exactly something to write home about. But it’s still an incredibly impressive first step, and refinement by the 3D printing community should be able to improve the quality dramatically.