Compostable Plastic Cutlery Can be Recycled Into Home-Insulating Foam

SEATTLE (Waste Advantage): Compostable plastic can be turned into a foam that functions as building insulation, creating a potential solution to difficulties in recycling the material. Polylactic acid (PLA) is a plastic made of fermented starch from corn or sugar cane. It is designed to break down into harmless material once used and disposed of, but doing so requires industrial composting, which isn’t available in all locations.

If PLA makes its way into the environment, it often won’t break down. Because of this, it is classed as compostable rather than biodegradable by the European Union. Now, Heon Park at the University of Canterbury in New Zealand and his colleagues have developed a method to convert plastic knives, spoons and forks made from PLA into a foam that can be turned into insulation for walls or flotation devices.

The researchers placed the PLA cutlery into a chamber filled with carbon dioxide. As they increased the pressure inside the chamber, the gas dissolved into the plastic. When they released the pressure, the gas expanded rapidly and turned the plastic into a foam. The process is entirely mechanical and involves no chemical reaction.

Courtesy: www.wasteadvantagemag.com