High Perfomance Fiber- Kevlar the Super Tough Fiber

In today’s fast growing market, apart from general apparel clothing, some special applications are expected from textile fibers. Such fibers are used specifically for protective clothing and thus require certain high performance properties. This generation of fibers has been recently developed in the 20th century and are called high performance fibers. A class of these fibers have very high tenacity and high modulus which are used in applications such as bullet proof jackets, whereas another class of fibers would have high thermal or chemical resistance which can be used as flame resistant fabrics etc. High performance fibers include polymeric fibers such as aramids, aromatic copolyesters, extended chain flexible polyolefin etc.; carbon fiber; glass fibers; ceramic fibers and metallic fibers. High performance polymeric fibers being used for high mechanical properties should be highly oriented, linear aliphatic or aromatic molecules since flexible chains would give low melting polymers and thus low thermal resistance. On the other hand, carbon fibers are planar graphite structures with outstanding mechanical properties. Inorganic fibers have a three dimensional structure compared to a one dimensional and two dimensional structure of polymeric materials and carbon fibers respectively. They have very good mechanical properties but are brittle and have the highest thermal resistance. However, carbon fibers as well as inorganic fibers (except glass fibers) are very expensive. In the following sections, particularly, polymeric fibers would be discussed in detail. Although in the past there were some research works had done and papers also been published, but this paper just simplifies the things as well as highlight some superb features of the Kevlar fiber. However this is not a research article rather than a review article.