Aramid fiber (1961) is a synthetic fiber, a fire-resistant polyamide, is a favorite for aerospace and military; bullet-proof protective "armor" fabric, as well as an asbestos substitute.
A well-known type of aramid fiber (a para-aramid) is commonly known by its Dupont trade name, Kevlar.
Aramid fiber characteristics
- sensitive to degradation from ultraviolet radiation
- good resistance to abrasion, chemical degradation, and thermal degradation
- nonconductive
- no melting point
- low flammability
- good fabric integrity at elevated temperatures
- para-aramid fibers such as Kevlar and Twaron, which have a slightly different molecular structure, also provide outstanding strength-to-weight properties, high tenacity and high modulus.
Major Industrial Aramid Fiber Uses
- flame-resistant clothing
- protective vests and helmets
- composites
- asbestos replacement
- hot air filtration fabrics
- tire and mechanical rubber goods reinforcement
- ropes and cables
- sail cloth (not necessarily racing boat sails)
- sporting goods
- drumheads
Production
The Federal Trade Commission definition for Aramid fiber is "A manufactured fiber in which the fiber-forming substance is a long-chain synthetic polyamide in which at least 85 percent of the amide linkages are attached directly to two aromatic rings."
Aramid fiber is produced by spinning a solid fiber from a liquid chemical blend. This relies on a co-solvent with an ionic component (calcium chloride) to occupy the hydrogen bonds of the amide groups, and an organic solvent (N-methyl pyrrolinidone) to dissolve the aromatic polymer; prior to DuPont's invention of this process, no practical means of dissolving the polymer was known.
First U.S. Commercial Aramid Fiber Production: 1961, DuPont Company.
Current U.S. Aramid Fiber Producers: INVISTA
See also