High-Temperature Nylon Is Automotive Contender

Automotive gears, bearings, valves, and sliding parts, as well as structural components and fuel tubing are the new thrust in applications for a high-heat nylon from Kuraray America, Inc., N.Y.C., sub. of Kuraray Co. in Japan.

Automotive gears, bearings, valves, and sliding parts, as well as structural components and fuel tubing are the new thrust in applications for a high-heat nylon from Kuraray America, Inc., N.Y.C., sub. of Kuraray Co. in Japan. Genestar PA9T is a unique semi-aromatic nylon sold in Japan since 1999 and in the U.S. for three years. Kuraray recently tripled capacity in Japan for PA9T neat resin to 6.6 million lb. Plans are being drawn up for a plant to make 22 million lb/yr.


Genestar’s uses so far have been mainly in electrical/electronic parts such as connectors and LED reflectors for printers, cell phones, and digital cameras. With its expan-ded capacity, Kuraray is now focusing on automotive parts. Genestar’s competition is mainly other high-heat nylons such as PA46 and PA6T. Genestar reportedly has much lower moisture absorption than those resins. It also boasts a higher Tg (125 C) and better toughness at elevated temperature than PA46, plus higher resistance to chemicals, fuels, and hydrolysis than PA6T. Genestar reportedly also beats other nylons as well as acetal and LCP in lubricity and wear resistance. With expanded production, Genestar’s price has dropped to a range between that of PA46 and PA6T and LCP.


In the past year, Kuraray has been developing extrusion grades to take advantage of Genestar’s fuel barrier properties, which are not shared by competing materials. Kuraray has cooperated with other resin producers to develop two types of fuel tubing. One is a two-layer structure of nylon 12 with a PA9T inner layer. The other has three layers: nylon 12 outer, PA9T middle, and ETFE inner.