ISO 20558-1:2018 establishes a system of designation for poly(phenylene sulfide) (PPS) thermoplastic materials, which can be used as the basis for specifications.

The types of poly(phenylene sulfide) (PPS) materials are differentiated from each other by a classification system based on appropriate levels of the designatory properties

a) melt mass-flow rate or melt viscosity;

b) density;

c) tensile modulus;

and on information about the intended application and/or method of processing, important properties, additives, colorants, fillers and reinforcing materials.

This document is applicable to all PPS materials. It applies to materials ready for normal use in the form of powder, granules or pellets and to materials unmodified or modified by colorants, additives, fillers, etc.

It is not intended to imply that materials having the same designation give necessarily the same performance. This document does not provide engineering data, performance data or data on processing conditions which can be required to specify a material for a particular application and/or method of processing. If such additional properties are required, they are intended to be determined in accordance with the test methods specified in ISO 20558-2, if suitable.

In order to specify a thermoplastic material for a particular application or to ensure reproducible processing, the requirements are given in data block 5 (see 4.1).