Eyeglass frames have been developed from plant-based, heat-resistant bioplastic BIOFRONT, by Teijin Limited and Teijin Chemicals Ltd. collaboration with Tanaka Foresight Inc. BIOFRONT is the world's first bioplastic to be used for all plastic parts of eyeglass frames, including the temples. Tanaka Foresight manufactures and sells approximately 60% of all plastic eyeglass parts in Japan.
BIOFRONT is an advanced polylactide that offers heat resistance comparable to that of oil-based plastics. Its melting point of 210 degrees, some 40 degrees higher than that of conventional polylactides, puts it on par with PBT, a leading engineering plastic. It is also highly resistant to bleaching and bacteria, making it ideal for the plastic parts of eyeglasses. 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. Teijin continues to enhance BIOFRONT's performance. Technologies for polymers and molecular-level control mechanisms have been used to minimize hydrolysis in BIOFRONT without affecting its inherent heat-resistant properties, which will enable automotive and electronics applications that require high resistance to heat and humidity. Teijin also is exploring possibilities for the chemical recycling of used BIOFRONT products, aiming to further enhance the environmental friendliness of the plant-based bioplastic.