PET (also named PETE) is a kind of polyester material for fiber, injection molded parts, as well as blow-molded bottles and jars. Special grades are offered with the required properties for the different applications. PET is linear thermoplastic (long-chain molecule consists of repeating units shown as figure right), white but bluish resin made from terephthalic acid and ethylene glycol through poly-condensation.
PET is supplied by the resin manufacturers in the form of small pellets, each about 0.05 gram. PET came into prominence in the 1950s as a textile material. Its strength, temperature tolerance and wear-resistance made it an ideal replacement for, or addition to natural fibers such as silk, cotton and wool.