3D Printer Filament Recycling is Super Green

A new analysis of 3D printing highlights many of the concerns about plastic 3D print stock.

3d printing, plastic, recycle, In a study recently released by the Michigan Technological University (MTU), Joshua Pierce and his group have found that recycling commonplace plastics into 3D printing filament consumes less energy than traditional recycling.

As part of his study Pierce conducted a lifecycle analysis of HDPE milk jugs commonly found in American households. After cleaning, shredding and converting the shredded material into filament Pierce’s team did an analysis of the amount of energy used in the entire process. After crunching the numbers the MTU team found that even compared to a municipal recycling program home recycling used about 3 percent less energy than the civic alternative.

While a 3 percent energy savings doesn’t seem like a lot, when compounded from household to household over time that unused energy could be sold or used in more profitable ways, which could have a major impact on cities. But beyond the savings that could be realized when compared to city and state sponsored recycling programs, people in areas without access to local recycling could see a major increase in energy savings if they chose to recycle their own plastic into print stock. 

“Where it really shows substantial savings is in smaller towns like Houghton, where you have to transport the plastic to be collected, then again to be recycled, and a third time to be made into products,” said Pearce, an associate professor of Materials Science and Engineering/Electrical and Computer Engineering. “Then the energy savings skyrocket to 70-80 percent. And, recycling your own milk jugs uses 90 percent less energy than making virgin plastic from petroleum.”

What’s more, recycling readily available plastics can significantly reduce the cost of a 3D print. With filament going for anywhere between $35 and $50 a kilo, there’s plenty of reason to reprocess your plastics into print material.

While it’s unlikely that many home 3D printer users will begin to make their own print stock, Pierce’s analysis does point to one obvious flaw in the current 3D printing paradigm. Current plastic filament is just too expensive to make the consumer AM market sustainable, and the novelty items that people produce are too toxic to our environment to see just one use.

Images Courtesy of Michigan Technology University