ISO 24025-1:2020

Overview

ISO 24025-1:2020 - Plastics - Sulfone polymer moulding and extrusion materials - Part 1: Designation system and basis for specifications establishes a standardized designation system for sulfone thermoplastics (polysulfone PSU, polyethersulfone PESU, and polyphenylsulfone PPSU). It defines how to describe composition, fillers/reinforcements, intended application/processing, and key designatory properties so the material can be unambiguously identified and used as the basis for specifications.

This standard applies to sulfone polymers that include ether oxygen in their repeat unit and to materials supplied as powder, granules or pellets - unmodified or modified with colorants, additives, fillers or reinforcements.

Key topics and requirements

• Designation system: A five-part individual-item block (data blocks 1–5) appended to the International Standard number. Each data block conveys:
  • Data block 1: Polymer identification (PSU, PESU, PPSU) and major component.
  • Data block 2: Fillers/reinforcements and their form/content (code letters and content codes).
  • Data block 3: Intended application or processing method and supplementary properties/additives.
  • Data block 4: Designatory properties (annealing code, temperature of deflection under load, melt mass-flow rate, Charpy notched impact strength, tensile modulus, yield stress) encoded in standardized ranges.
  • Data block 5: Optional additional specification details for reproducible processing or application-specific requirements.
• Designatory properties: Includes temperature of deflection under load, melt mass‑flow rate (MFR), Charpy notched impact strength, tensile modulus, and yield stress. Test methods and specimen preparation references point to ISO 24025-2.
• Test conditions & coding: The standard gives coded ranges and annealing/test condition codes rather than raw engineering or processing parameters. It does not provide detailed performance or processing instructions; additional property testing follows ISO 24025-2 when needed.
• Limitations: Identical designations do not necessarily guarantee identical performance - manufacturing tolerances and formulation differences can affect results.

Practical applications

• Creating supplier and material data sheets for PSU/PESU/PPSU compounds
• Defining material selections for injection moulding, extrusion, thin-walled parts, or high-temperature components
• Standardizing procurement/specification language in OEM contracts and quality documents
• Guiding labs and QA teams on which designatory properties to test and report

Who uses this standard

• Material manufacturers and compounders
• OEMs and design engineers specifying thermoplastic components
• Procurement and quality assurance teams
• Testing laboratories and certification bodies
• Standards and compliance specialists

Related standards

• ISO 24025-2 - Preparation of test specimens and determination of properties (referenced for test methods)
• ISO 1043-1 - Symbols and abbreviated terms for plastics (polymer codes)

Keywords: ISO 24025-1:2020, sulfone polymer, PSU, PESU, PPSU, designation system, melt mass-flow rate, temperature of deflection under load, Charpy notched impact strength, tensile modulus, thermoplastic specification.