Acetal (Polyoxymethylene) (POM)

Commonly known as Acetal, polyoxymethylene (POM) is a thermoplastic produced by the addition polymerization of aldehydes through the carbonyl function, yielding unbranched polyoxymethylene chains of great length. It is commonly produced as both a homopolymer and a copolymer. The material is characterized by good fatigue endurance, resilience, low moisture sensitivity, high solvent and chemical resistance, and good electrical properties.
Acetal is often used for precision automobile and consumer electronic parts that require high stiffness, low friction and excellent dimensional stability. POM is commonly extruded as continuous lengths of round or rectangular section which can be cut and sold as bar or sheet stock for machining. POM is also processed through injection molded and blow-molding techniques.

In 1959, DuPont became the first company to market acetal under the trade name Delrin. The Celanese Corporation quickly followed suit, producing an acetal copolymer known commercially as Celcon in 1962. The Celanese Corporation partnered with other ventures to produce similar products in other countries.  For example, they partnered with Farbwerke Hoechst in Germany to manufacture Hostaform.
See also POM Copolymer and POM Homopolymer
J. A. Brydson, Plastics Materials, 4th ed., 476, 487.
Whittington’s Dictionary of Plastics, 2nd ed., 3.