Synthetic Fibers

Synthetic fibers

In addition to polyamide 6 (perlon) and 6.6 (nylon), highly crimped and antistatic polyamide fiber types and aramids are also used in technical textiles. The latter are aromatic polyamides in whose molecular chains aromatics are linked by amide groups to form chain molecules. This fiber structure with largely elongated molecular chains and many crystalline regions results in higher strength and temperature resistance.

Polyamide and polyester have a low moisture absorption of 3.5% to 4.5%. Texturing creates cavities (capillaries) in the yarn through which moisture can be easily transported. Furthermore, polyamide and polyester have a very high tear and abrasion resistance. The wet strength is 80 to 90% of the dry strength. With aramids, the strength is about 5 times as high. The maximum tensile elongation is very high in the dry and wet state and, depending on the fiber type and degree of stretching, is 20 to 80% for polyamide and 15 to 50% for polyester. Electrostatic charging is strong but can be reduced by incorporating antistatic metallic filaments. The fiber fineness ranges from microfiber to coarse fibers. Depending on fiber fineness, surface construction and finishing, the fabrics are also fine and soft to stiff. Since both polyamide and polyester are thermoplastic, they can be permanently deformed when exposed to heat. Chemical resistance to alkalis and solvents is very good, but they are not resistant to strongly concentrated acids and alkalis. When exposed to intense light, polyamide fibers age, lose their strength and turn yellow. However, they can be made more resistant by melting in additives. The light resistance of polyester, on the other hand, is generally very good. Both polyamide and polyester are resistant to fungi and putrefactive bacteria; they do not rot. Polyamide is sensitive to the effects of dry heat, while polyester has the highest temperature resistance.

In addition to normal polyester fiber types, there are special types, e.g. high-temperature resistant, antistatic, deep melting binder fibers or profile fibers, as well as high-strength / high-tenacity types, which are used in our technical textiles.

Polytetrafluoroethylene is mainly processed into membrane films with microporous openings, but also into filament yarns and staple fibers. Fluoro fibers are chemical resistant, water repellent, do not absorb moisture and slide on other fabrics.

Polyethylene and polypropylene belong to the group of polyolefins. Polyethylene has low density and low softening range. It does not absorb water and, like polypropylene, is resistant to many chemicals.

Textile fiber materials can be divided into groups according to their fineness: Coarse, fine, ultra-fine and microfibers. The latter are generally man-made fibers of polyester and polyamide with a titer finer than 1dtex.

Blending of fibrous materials is intended to eliminate disadvantageous properties of a particular fibrous material to improve quality. In addition, blends affect processing properties, yarn count, and economy.