Aramid fibers are a class of heat-resistant and strong synthetic fibers. They are used in aerospace and military applications, for ballistic-rated body armor fabric and ballistic composites, in bicycle tires, marine cordage, marine hull reinforcement, and as an asbestos substitute. The name is a portmanteau of “aromatic polyamide”. The chain molecules in the fibers are highly oriented along the fiber axis. As a result, a higher proportion of the chemical bond contributes more to fiber strength than in many other synthetic fibers aramides have a very high melting point (>500).
Aromatic polyamides were first introduced in commercial applications in the early 1960s, with a meta-aramid fiber produced by DuPont as HT-1 and then under the trade name Nomex. This fiber, which handles similarly to normal textile apparel fibers, is characterized by its excellent resistance to heat, as it neither melts nor ignites in normal levels of oxygen. It is used extensively in the production of protective apparel, air filtration, thermal and electrical insulation as well as a substitute for asbestos. Meta-aramid is also produced in the Netherlands and Japan by Teijin Aramid under the trade name Teijinconex, in Korea by Toray under the trade name Arawin, in China by Yantai Tayho under the trade name New Star, by SRO Group (China) under the trade name X-Fiper, and a variant of meta-aramid in France by Kermel under the trade name Kermel.
Based on earlier research by Monsanto Company and Bayer, para-aramid fiber with much higher tenacity and elastic modulus was also developed in the 1960s–1970s by DuPont and Akzo Nobel, both profiting from their knowledge of rayon, polyester and nylon processing. In 1973 DuPont was the first company to introduce a para-aramid fiber called Kevlar to the market. A similar fiber called Twaron with roughly the same chemical structure was introduced by Akzo in 1978. Due to earlier patents on the production process, Akzo and DuPont engaged in a patent dispute in the 1980s. Twaron is currently owned by the Teijin company.