Overview
ISO 21970-2:2019 specifies how to prepare test specimens and determine properties of thermoplastic polyketone (PK) moulding and extrusion materials. It defines handling and conditioning requirements, prescribes injection‑moulding preparation, and lists standard test methods (selected from ISO 10350‑1 and other widely used standards) to obtain reproducible and comparable property data for PK materials.
Key topics and requirements
- Specimen preparation: Specimens shall be produced consistently by injection moulding (refer to ISO 294‑1). The document emphasizes that specimens must always be prepared by the same procedure and processing conditions to ensure comparability.
- Pre‑processing moisture control: Moisture content of material before moulding shall not exceed 0.2% by mass. If higher, dry per the manufacturer's instructions.
- Injection‑moulding conditions: Specimens are moulded according to ISO 294‑1 and the temperature/pressure parameters provided in the standard’s Table 1 for PK materials.
- Conditioning before testing: Condition specimens in the standard atmosphere for 48 h at (23 ± 2) °C and (50 ± 10) % relative humidity (ISO 291) unless stated otherwise.
- Test atmosphere: All tests are carried out in the standard atmosphere unless specific tests state different conditions.
- Selected properties and methods: The standard maps PK‑relevant properties and test methods (from ISO 10350‑1 and other standards), including:
- Rheological: Melt mass/volume flow rate (ISO 1133‑1)
- Mechanical: Tensile (ISO 527‑1/2), flexural (ISO 178), Charpy impact (ISO 179)
- Thermal: DSC glass transition and melting (ISO 11357‑2/3), heat‑deflection (ISO 75)
- Physical: Density (ISO 1183 series), water absorption (ISO 62), ash content
- Electrical and flammability: Permittivity, resistivity (IEC/ISO electrical standards), oxygen index, burning/flame tests
- Special tests: Puncture impact (ISO 6603‑2), coefficient of linear thermal expansion (ISO 11359‑2), UV exposure (ISO 4892 series)
- Reproducibility note: Results are intended to be reproducible and comparable, but may differ if specimens or procedures vary.
Applications and users
ISO 21970‑2 is intended for:
- Material suppliers and compounders preparing specification data sheets for PK grades
- Testing laboratories performing certification, R&D or quality control
- Product designers, OEMs and engineers who require comparable material property data for component selection and simulation
- Regulatory and procurement teams needing standardized test methods for material comparison
Practical uses include material selection, supplier comparison, product development, failure analysis, and establishing quality acceptance criteria.
Related standards
- ISO 21970‑1 (designation system and basis for specifications)
- ISO 10350‑1 (acquisition/presentation of comparable single‑point data)
- ISO 294‑1 (injection moulding of test specimens), ISO 291 (conditioning), plus numerous ISO/IEC standards cited for specific tests (see normative references in ISO 21970‑2).
Keywords: ISO 21970‑2, polyketone, PK moulding materials, test specimens, injection moulding, conditioning, mechanical properties, thermal properties, electrical properties, ISO 10350‑1.