by Green Plastics
Why is this cool?
“Although acetate is commonly used for the plastic parts of eyeglasses, contact with cosmetics or hair-styling products can result in bleaching. Acetate also tends to warp under high heat and can cause skin rashes. The bioplastic polylactide has been used for eyeglass nose pads because its antibacterial properties help to avoid rashes, but conventional polylactide has not been used for other parts such as frames and temples because of insufficient heat resistance.”
The material produced by Teijin LTD, Biofront , isn’t just any PLA. It is a stereocomplex PLA, meaning that it mixes the standard Poly-L-lacticacid polymer with their enantiomer poly-D-lacticacid polymer. This combination gives the resulting “stereocomplex” material different properties; specifically, and importantly, it has a melting point of 210 degrees, some 40 degrees higher than that of conventional PLA and putting it on par with PBT, a leading engineering plastic. BIOFRONT also is highly resistant to bleaching and bacteria, making it ideal for the plastic parts of eyeglasses.