Stefan took on the challenge of recycling compostable plastic utensils, made from polylactic acid (PLA), into 3D printing filament. He noted the significant waste generated daily from disposable plastic spoons, knives, and forks and sought to repurpose them into a more sustainable material.
His initial attempts to process the utensils involved a blender, but this proved ineffective. Stefan then turned to an industrial plastic shredder, which successfully reduced the utensils to coarse dust. After drying the material, he used an extruder to create filament. However, the resulting filament was thin and brittle, likely due to the utensils being optimized for injection molding.
In a second attempt, Stefan mixed the ground-up utensils with fresh PLA in equal proportions. This 50% recycled mix produced more usable filament. Experimenting with a different brand of compostable plasticware also yielded better results.
For a more challenging test, Stefan intentionally soiled the plastic utensils with tomato sauce, then cleaned, dried, and shredded them. Mixing this recycled material with 20% new PLA and pigment resulted in a usable filament. While the economic feasibility of this process may be debatable, the project demonstrates a commitment to recycling and explores the potential of repurposing compostable plastics for 3D printing applications.
Read more: 3D Printing with Plastic Cutlery