Aramid fibre is an innovation and modified form of polyamide Nylon. Further innovations were carried out to develop a fibre which can have enormous advantages over nylon fibres and possess unique properties such as ultra-high strength, rigid & highly oriented molecular structure, lightweight, low flammability, resistance to abrasion & organic solvents, etc. The Aramid fibres were developed which means Ar—-Aromatic, and amid—Amides.
Two aromatic rings are attached to Amide linkages and are called aromatic polyamides. These are classified in two forms with their trade names Nomex (meta-aramid) and Kevlar (para-aramid). These two are most common. The other names are Twaron, technora, Heracron, etc. They are modified forms of polyamides (Nylon, Polyester)
ARAMID is a synthetic fibre that is produced by spinning a solid fibre from solution. The initial preparation of the polymer is generally achieved by a chemical reaction between the amine group and a carboxylic acid halide group. Once the polymer has been produced, the aramid fibre is then created by spinning. This was developed by DuPont with their trade name Kevlar fibre and Teijin developed Twaron fibre. There are many grades available in the market with properties to suit their applications, especially in aerospace and military industries. The inherent bond strength is due to the orientation of molecules along the fibre axis. Aramid is a synthetic fibre that is produced by spinning a solid fibre from solution. The initial preparation of the polymer is generally achieved by a chemical reaction between the amine group and a carboxylic acid halide group. Once the polymer has been produced, the aramid fibre is then created by spinning.
Kevlar is manufactured from a polymer which is highly insoluble in the solution and needs to add concentrated sulfuric acid. This is necessary to keep the highly insoluble polymer in solution form during synthesis and spinning.
The manufacturing process of Kevlar is expensive and dangerous partly because it is dissolved in concentrated sulfuric acid. Unlike HDPE high molecular weight polyethylene, the kevlar® molecule is polar. This property allows other substances including water to attach themselves to the Aramid. This allows it to be more active chemically than UHMWPE (Dyneema®, Spectra®) It also means it can be bonded for example to epoxy, and it is wettable.
DuPont™ Kevlar® is an organic fibre in the aromatic polyamide family. The unique properties and distinct chemical composition of wholly aromatic polyamides (aramids) distinguish them – and especially Kevlar® – from other commercials, man-made fibres.
Kevlar® has a unique combination of high strength, high modulus, toughness and thermal stability. It was developed for demanding industrial and advanced-technology applications. Currently, many types of Kevlar® are produced to meet a broad range of end uses.
Aramid definition—This product has been defined in different ways as per their inherent properties by different researchers.
- any of a class of synthetic polyamides that are formed from aromatic monomers, and yield fibres of exceptional strength and thermal stability.
- any of a class of synthetic aromatic long-chain polyamides capable of extrusion into fibres having resistance to high temperatures and great strength.
- any of a group of synthetic fire-resistant and strong polyamides used to make textiles or plastics
- any of a group of lightweight but very strong heat-resistant synthetic aromatic polyamide materials that are fashioned into fibres, filaments, or sheets and used especially in textiles and plastics.
- any of various flame-resistant and strong synthetic fibres used in.
- Keany of a class of synthetic aromatic long-chain polyamides capable of extrusion into very strong heat-resistant fibres.
- English dictionary definition of aramid fibre. n. A strong, heat-resistant fibre formed of polymers with repeating aromatic groups branching from a carbon backbone, having flame retardant properties
- The word aramid comes from a blend of the words “aromatic” and “polyamide” and is a general term for a manufactured fiber in which the fiber-forming substance is a long chain synthetic polyamide, in which at least 85% is of amide linkages (-CO-NH-) attached directly to two aromatic rings, (as defined by the U.S Federal)