Development of Eco-friendly Polyester Staple Nanofiber that Reinforces Rubber

Teijin Frontier Co., Ltd., has developed an eco-friendly staple polyester nanofiber that offers excellent performance to reinforce rubber uses in products including automotive tires, hoses and belts. Teijin Frontier will start production in 2023 and expects sales to reach JPY one billion (nearly USD 8.2 million) by the fiscal year ending in March 2028.

The new staple nanofiber incorporates both polyester nanofiber and polyethylene polymers, which are combined in Teijin Frontier’s proprietary sea-island composite cross section. Different polymers are used for the “sea” and “island” parts to improve rubber reinforcement. A polyester nanofiber with a diameter of either 400nm or 700nm is used as the island as reinforcing material and the surrounding sea part is made with polyethylene, which mixes easily with rubber. Compared to conventional products, mixing takes place at the molecular level, which enables thousands of times more nanofibers to be evenly dispersed in the rubber for equal or better reinforcing but requiring a relatively small amount.