Nanofiber Reinforces Rubber Tires, Hoses, Belts


Teijin Frontier 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 US$ 8.2 million by fiscal 2028.

The new staple nanofiber incorporates both polyester nanofiber and polyethylene, 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 400 nm or 700 nm 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.

The length of the new staple nanofiber is just 1mm or less, but the aspect (length-to-diameter) ratio is high thanks to the small diameter, which contributes to reinforcing. Further, the fiber’s short length prevents entanglement and twisting, and additionally helps to disperse the fibers and rubber evenly. The fiber forms continuous lines or surfaces, rather than dispersed clumps. In actual use, the fibers rather than the rubber absorb deformation stress, resulting in more durable rubber products.