PLA Recycling
I've been working on this project since Sept. 2020 through the NYU MakerSpace. My coworkers and I built a plastic shredder from scratch to deal with the plastic problem at MakerSpace. The goal of the project was to integrate a circular economy into NYU through the shredder which would assist in recycling PLA waste.
PLA Collection Bins
The Plastic Problem
The MakerSpace is an amazing space where ideas thrive and prototyping is welcomed. One way they accomplish this is by providing over 10 Ultimaker+ 3D printers for the NYU students to use, all for free.
With these free for all printers, comes lack of regard for the PLA usage as students can reprint as much as they like without paying for anything. And by no means am I saying it's bad to provide free 3D printing, in fact it has led to some amazing projects (you can find some at the bottom of this page link). My spiel is that students do not put much effort to ensure their print has the right measurements, infill, and so on; which then leaves them printing the same file multiple times only to want one of the many prints. The result is the picture of bins filled with PLA, a whopping 10kg collected from just one semester (3 months).
The question remains, where do the rest of those unwanted prints go? In the trash they went until... we made a plastic shredder to recycle all this waste!
The Shredder
Taking heavy inspiration from Precious Plastic by following their guide to making a plastic shredder, we were able to make one in house using mostly scrap materials. Parts were waterjet cut, 3D printed, and welded together all to create this one shredder. Using the shredder, we were able to create a cycle of sustainability: PLA is used for 3D printers -> 3D print is discarded -> Discarded print is shredded -> PLA bits are reused. The original plan was to reuse the PLA bits for PLA spools but the machine that creates spools needs a bit more tinkering. In the meantime we were able to reuse the bits to create PLA sheets by melting the bits onto a baking sheet. These PLA sheets can be laser cut using the MakerSpace's universal cutter machine. An example cut is shown below of a dragon using the PLA sheets.
Plastic Shredder
GG 2021 Final Report Circular Design at NYU MakerSpace.docx.pdf