This part of EN ISO 9988 establishes a system of designation for polyoxymethylene (POM) thermoplastic materials, which may be used as the basis for specifications.
Polyoxymethylene materials are thermoplastic materials composed principally of long-chain synthetic
homopolymers and copolymers of formaldehyde. The repeating unit in the molecular chain is - CH2O - as an integral part of the main polymer chain resulting from polymerization of formaldehyde.
The types of polyoxymethylene plastic are differentiated from each other by a classification system based on appropriate levels of the following designatory properties:
a) melt mass-flow rate or melt volume-flow rate,
b) tensile modulus,
and on information about basic polymer parameters, intended application, method of processing, important properties, additives, colorants, fillers and reinforcing materials.