POM (polyformaldehyde resin) Definition: Polyformaldehyde is a linear polymer with no side chain, high density and high crystallinity. According to the chemical structure of its molecular chain, it can be divided into homopolyformaldehyde and copolyformaldehyde two kinds. The important differences between the two are: homopolyformaldehyde density, crystallinity, melting point are high, but the thermal stability is poor, the processing temperature range is narrow (about 10℃), and the stability of acid and base is slightly low; The density, crystallinity, melting point and strength of copolyformaldehyde are low, but the thermal stability is good, it is not easy to decompose, and the processing temperature range is wide (about 50℃), and the stability of acid and base is good. It is an engineering plastic with excellent comprehensive properties. It has good physical, mechanical and chemical properties, especially excellent friction resistance. Commonly known as steel or steel, it is the third largest general engineering plastic.