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Aramid

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.

Contents

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

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