October 8, 2019 – WSU research shows that coffee grounds, usually viewed as a waste product, can be used to form a new, stronger type of plastic.
Poly‑lactic acid (PLA), derived from corn starch, is used in medical supplies and for 3D printing, said Yu-Chung Chang, research lead and Ph.D. candidate in material engineering. On its own, PLA is brittle but when combined with oil coming from used coffee grounds, it’s more sustainable and cleaner, he said. “What we use is actually the waste part of the waste, where it has almost no monetary value,” Chang said. “But once we add it into our 3D printing subject, and it becomes something better.”
“The coffee mixes very well with the PLA for this use,” said Cheng Hao, Ph.D. candidate in material science. Adding a waste product to the plastic keeps the cost down and makes it almost completely biodegradable, Chang said.