“It was super cool to use the material for the first time,” Truong said. “We made it ourselves and we’re turning what would just be thrown away into another useful project for a student.”

The filament extruder system — dubbed “Bob Ross” because “it takes our filament mistakes and makes them into happy little 3D-printed trees,” Garciaacosta said — helps students involved in the lab develop sustainable habits and consider the environment in their work.

Closing the loop

When Martinez and McWhorter first proposed the idea of an extruder system in their lab, ASU’s Zero Waste Associate Director Alana Levine was immediately on board.

The system plays into the bigger trends of recycling, sustainability and circularity at ASU and beyond.

People and businesses are becoming more aware of the need to reduce their use of single-use plastics. Starbucks, American Airlines and other major companies, for instance, recently stopped using plastic straws.

Global economic policies have also made local recycling solutions more important.

“China, for example, has really cracked down and created a lot of policy to not take a lot of waste material,” Levine said. “It’s paramount to find downstream solutions for these types of materials we’re generating as waste.”

Items on a tray printed with recycled 3D printer plastic filament.

A USB drive holder made out of recycled PLA plastic created in the 3D Print and Laser Cutting Lab. Photo by Erika Gronek/ASU

Levine emphasizes the importance of circularity, or putting these waste materials back into the marketplace as another useful material or item.

In practice, this circularity loop can be at the global scale, but the smaller the loop, the less impact there is on using additional resources to ship materials and recycled products.

“Ideally it would be great if we can have local reprocessing for our waste materials,” Levine said.

The extruding tool at the 3D Print and Laser Cutting Lab is an example of local reprocessing.

“I love that there was an opportunity to demonstrate a fairly complex process of waste material production, collection, reprocessing and getting that product back into a stage where it can then be useful again, where we’re directly recycling and not downcycling the plastic or making it less valuable,” Levine said.

Future steps

PLA can’t be recycled infinitely. Martinez notes other labs that use similar recycling systems recommend only recycling the same material a couple of times. So she and the students find other ways to reduce waste.

However, not everything that’s printed will be thrown away and it isn’t an immediate concern for the team.

Garciaacosta says the students who help manage the lab also try to find optimal ways to design each print to minimize material usage and other factors. The goal is to design smarter, not harder.

“I sometimes suggest people use a combination of 3D printing and laser cutting wood, for example making their base out of wood and 3D printing the joints for a job that uses much less plastic and is faster to produce,” Garciaacosta said. “It makes people think how they can optimize designs and make them more environmentally friendly because they’re using less material.”

Martinez is also working with other campus labs with 3D printers to collect their waste PLA material. She’s also contacting labs that produce plastic waste compatible with recycling into 3D printer filament. For example, syringe caps from biomedical engineering labs can be recycled using the extruder tool.

Levine is also helping to reach out to corporations and companies outside of ASU to provide their waste materials to ASU recycling programs like this one.

“The ultimate goal is to collect so much recycled material that it would be too much for us to handle to reuse here as finished spools,” Martinez said. “We talked about donating recycled PLA to K–12 STEM programs that have 3D printers at their schools to reduce their expenses.”

Martinez believes this is a good practice for her students to take with them to industry.

“The idea is to incorporate recycled plastic and other materials into their existing engineering builds,” she said. “It helps them create good habits and consider the environment.”

Monique Clement

Lead communications specialist, Ira A. Fulton Schools of Engineering