Polyphthalamide is a thermoplastic

Thermoplastic

Thermoplastic, also known as a thermosoftening plastic, is a polymer that turns to a liquid when heated and freezes to a very glassy state when cooled sufficiently...

 synthetic resin

Synthetic resin

Synthetic resins are materials with a property of interest that is similar to natural plant resins: they are viscous liquids that are capable of hardening permanently. Otherwise, chemically they are very different from the various resinous compounds secreted by plants .The synthetics are of several...

 of the polyamide

Polyamide

A polyamide is a polymer containing monomers of amides joined by peptide bonds. They can occur both naturally and artificially, examples being proteins, such as wool and silk, and can be made artificially through step-growth polymerization or solid-phase synthesis, examples being nylons, aramids,...

 (nylon

Nylon

Nylon is a generic designation for a family of synthetic polymers known generically as polyamides, first produced on February 28, 1935, by Wallace Carothers at DuPont's research facility at the DuPont Experimental Station...

) family that is used to replace metals in high temperature automotive applications, as the housing for high temperature electrical connectors and multiple other uses. It has found a degree of favor for use in cutlery. Cold Steel

Cold Steel

Cold Steel is a Ventura, California-based maker of knives, swords and other edged weapons and tools. Cold Steel was founded in 1980 by company president, Lynn C. Thompson...

 has advertised the glass fibre reinforced series as being stealthy (due to them not being detected by metal detectors and having no metallic reflections) and, being made of "Grivory" (a trade name), stronger than previous models made of "Zytel".

As a member of the nylon family, it is a semi-crystalline material composed from a diacid

Carboxylic acid

Carboxylic acids are organic acids characterized by the presence of at least one carboxyl group. The general formula of a carboxylic acid is R-COOH, where R is some monovalent functional group...

 and a diamine

Amine

Amines are organic compounds and functional groups that contain a basic nitrogen atom with a lone pair. Amines are derivatives of ammonia, wherein one or more hydrogen atoms have been replaced by a substituent such as an alkyl or aryl group. Important amines include amino acids, biogenic amines,...

. However, the diacid portion contains at least 55% terephthalic acid

Terephthalic acid

Terephthalic acid is the organic compound with formula C6H42. This colourless solid is a commodity chemical, used principally as a precursor to the polyester PET, used to make clothing and plastic bottles. Several billion kilograms are produced annually...

 (TPA) or isophthalic acid

Isophthalic acid

Isophthalic acid is an organic compound with the formula C6H42. This colourless solid is an isomer of phthalic acid and terephthalic acid. These aromatic dicarboxylic acids are used as precursors to commercially important polymers, e.g. the fire-resistant material Nomex...

 (IPA). TPA or IPA are aromatic components which serve to raise the melting point, glass transition

Glass transition

The liquid-glass transition is the reversible transition in amorphous materials from a hard and relatively brittle state into a molten or rubber-like state. An amorphous solid that exhibits a glass transition is called a glass...

 temperature and generally improve chemical resistance vs. standard aliphatic nylon polymers.

PPA is manufactured under trade names Amodel, Grivory, VESTAMID HTplus and Zytel

Zytel

Zytel is a trademark owned by DuPont and used for a number of different high strength, abrasion and impact resistant thermoplastic polyamide formulations of the family more commonly known as nylon, often with varying degrees of fiberglass, from 13% to 60%, added in for additional stiffness.Some of...

(r) HTN.