ISO 24022-2:2020

Overview

ISO 24022-2:2020 - Plastics - Polystyrene (PS) moulding and extrusion materials - Part 2: Preparation of test specimens and determination of properties - defines standardized procedures for preparing test specimens and measuring the physical, mechanical, thermal, electrical and other properties of polystyrene (PS) moulding and extrusion materials. The standard ensures reproducible, comparable data for quality control, material specification, and product design.

Key topics and technical requirements

• Specimen preparation: Injection-moulded specimens shall be produced in accordance with ISO 294-1 / ISO 294-3. The standard emphasizes consistent processing conditions and notes that bar test specimens (ISO 20753) often give better precision than directly moulded final-dimension parts.
• Injection moulding conditions (typical): Melt temperature 220 °C, mould temperature 45 °C, average injection velocity 200 ± 20 mm/s (see Table 1). An appropriate hold pressure must be used to obtain blemish-free mouldings.
• Uniformity requirement: Moulding masses shall not differ by more than 1% between specimens.
• Conditioning: After moulding, specimens must be conditioned per ISO 291 for at least 16 hours at 23 °C ± 2 °C and (50 ± 10) % relative humidity before testing.
• Property selection and test methods: Properties are selected primarily from ISO 10350-1 and supplemented by widely used or PS‑specific tests. Key properties include:
  • Rheological: Melt mass-flow rate (MFR), MVR, moulding shrinkage
  • Mechanical: Tensile modulus, stress/strain at break, creep, flexural modulus/strength, Charpy impact, tensile-impact
  • Thermal: Glass transition (DSC), heat deflection temperature (HDT), Vicat softening, coefficient of linear thermal expansion
  • Flammability and ignition: IEC/IEC test flames, oxygen index
  • Electrical: Relative permittivity, dissipation factor, volume/surface resistivity, electric strength, comparative tracking index (CTI)
  • Other: Water absorption, density, residual styrene monomer, refractive index, puncture energy/force

Applications and users

ISO 24022-2:2020 is used by:

• Polymer producers and compounders for routine quality control and material certification
• Independent testing laboratories to produce comparable, defensible test data
• OEMs and designers to select appropriate PS grades for moulding and extrusion applications
• Standards writers and specifiers for inclusion in technical datasheets and contractual specifications
• Regulatory and safety teams when assessing flammability, electrical properties or residual monomer limits

Practical benefits include consistent material comparisons, reliable datasheets, better process control, and clearer communication between suppliers and customers.

Related standards

• ISO 24022-1 (designation system and basis for specifications)
• ISO 10350-1 (data acquisition and presentation)
• ISO 294-1 / ISO 294-3 (injection moulding of test specimens)
• ISO 291 (conditioning), ISO 1133-1 (MFR), ISO 527, ISO 178, ISO 306, ISO 2561, ISO 20753, and relevant IEC electrical/flame test standards.