UC Berkeley Students Develop Campus-Wide 3D Printing Filament Recycling Program

At the University of California Berkeley, nearly 600 pounds of plastic trash is generated every year – and while there are many contributing factors like plastic bottles, the school’s more than 100 3D printers have definitely raised the amount. While the university has done some wonderful things with its printers, the unfortunate flip side is that the garbage bins quickly fill up with failed prints and scraps of unused filament.

Efforts have been made to recycle 3D printer filament on campus, and some of UC Berkeley’s labs try to buy recycled filament, but three students are now leading an effort to create an organized, campus-wide recycling system for 3D printer waste. Undergraduates Nicole Panditi, a mechanical engineering student, and Scott Silva, an environmental sciences student, along with PhD student Mickey Clemon, are leading the 3D Printer Filament Reclamation Project with help from the Cal Zero Waste facility.

“It’s my personal goal to reduce inefficiencies in 3D printing so that the tech industry can reach its full beneficial potential without being haunted by mountains of ugly waste,” said Panditi.

The filament reclamation process is surprisingly low-tech; after the plastic waste has been collected from bins stationed in 3D printing labs, the scraps are placed in an ordinary kitchen blender for 20 minutes to grind them up. The ground-up plastic is then melted, along with new PLA pellets for quality, and extruded through a filament extruder onto new spools. According to Lin King, manager of Cal Zero Waste and adviser to the Filament Reclamation Project, the goal is to create a “closed loop” of 3D printer plastic, so that not only are they keeping plastic out of the landfill, they’re saving money and lowering their carbon footprint by making their own filament.

“The idea is that the plastics would never have to leave campus,” King said. “We would provide Berkeley-produced recycled filament and any discarded items would be sent right back to us.”

3D printers are being used by students all across the Berkeley campus – which is great, but also a double-edged sword, especially when it comes to people who are inexperienced with 3D printing. According to Panditi, about half of the prints created by novice 3D printer users fail.

“That’s what is great about 3D printing, and that’s also why there is so much trash generated,” she said. “In rapid prototyping, you’re making iteration after iteration until you get it perfect. What happens with all those iterations is you throw them away. And that’s where all the plastic trash comes in.”

Plastic waste generated by 3D printing is an ongoing issue that many people have stepped forward to mitigate, coming up with a wide variety of recycling options for environmentally-conscious 3D printing enthusiasts. PLA, which is the most popular filament at Berkeley, is more problematic than many people realize. It’s touted as biodegradable, which it is – but only under very specific conditions that typically aren’t met in a backyard compost pile.

Even some industrial composting facilities don’t handle PLA well – the plastic can take up to two months to biodegrade even in specialized industrial conditions, and many facilities, including Republic Services West Contra Costa Landfill, which Berkeley uses, will sift through their compost after a typical 45-day cycle and throw out any remaining plastic. That particular facility says that it’s in the process of extending how long they allow plastics to remain in the compost pile, but in the meantime, recycling is the safer bet.

Panditi and Silva gather plastic from one of the Berkeley 3D printing labs.

Unfortunately, PLA is also difficult to recycle by conventional means. Some facilities won’t take it at all, as it’s tough to distinguish from other types of plastic, and even a small amount can contaminate a load of conventional, non bio-based plastic, which is where the money is for recycling facilities. The most eco-friendly solution, it seems, is to reuse and recycle it yourself, as Berkeley is doing.

As the Filament Reclamation Project team works towards officially introducing the system campuswide, they’re trying to raise money through a crowdfunding campaign that has a little less than 11 days left. Grinding up plastic in blenders isn’t exactly the most efficient way to process the heaps of waste that will be coming in as the project grows, so they’re hoping to raise $5,000 by the end of February so they can buy an industrial grinder and other equipment. Go check the campaign out; if you donate, you can get some cool rewards such as 3D printed items of your choice. Discuss in the UC Berkeley forum at 3DPB.com.