Picking up a biodegradable fork may seem like an environmentally friendly choice, but these utensils still require new materials for their production and oftentimes won’t actually degrade naturally. Fortunately, researchers at the University of Canterbury in New Zealand have come up with a way to turn biodegradable plastics into the foam for insulation.
To conduct this circular process, knives, spoons, and forks made of corn are put into a chamber where carbon dioxide is dissolved into the plastic at high pressure. When the chamber is depressurized, the carbon dioxide expands, creating a “foaming” effect.
Biodegradable materials are difficult to recycle because of their flimsy structure, by using them for foam insulation means they don’t have to be strong to be useful.
“Our views regarding biodegradable plastics can be broadened,” said Heon Park, a chemical engineer working on the concept. “Eventually, it will help reduce plastic pollution and maximize usage of materials.”
Source study: Physics of Fluids – Recycling and rheology of poly(lactic acid) (PLA) to make foams using supercritical fluid