Overview
ISO 23231:2025 - Textiles - Determination of dimensional change of fabrics - Accelerated machine method - specifies an accelerated test method and apparatus for measuring dimensional change (shrinkage or growth) of fabric specimens that will be used to make garments or other laundered end‑use articles. The method uses a programmable, perforated drum apparatus that simulates multiple domestic or industrial laundering and wet‑processing actions. It is intended for production and internal quality‑control decisions, not for developing care labels.
Key topics and technical requirements
- Test principle: Assess relaxation/shrinkage by subjecting specimens to a short hot wash cycle followed by several short rinse/extract/dry cycles while yarns move and flex; dimensional change is determined by comparing benchmark distances before and after the programme.
- Apparatus: Vertical perforated drum with radial partitions, reversible motion, air heater and water heater; programmable wash/rinse/spin/dry cycles; specified air pressure and water level settings.
- Specimens and benchmarks:
- Standard specimens: 190 × 190 mm aligned with length/width directions, marked with (125 ± 1) mm benchmark distances.
- Alternative: 255 × 255 mm specimens marked diagonally for (255 ± 1) mm benchmarks.
- Minimum of four specimens per sample; additional specimens recommended to improve precision.
- Sampling and preparation: Cut specimens parallel (or diagonal) to fabric directions; mark benchmarks with indelible pen; record original distances (nearest mm) or measure percent change directly.
- Measurement & calculation: Measure benchmark distances after testing and calculate percent dimensional change (average to 0.1 %). Negative values indicate shrinkage; positive values indicate growth.
- Limits and exclusions:
- Less suitable for heavy, tightly woven fabrics (e.g., denim) and fabrics with water‑repellent finishes.
- The method does not use detergents (and is not intended for care label development).
- Precision evidence: An interlaboratory study across five labs and five fabrics showed standard deviations no greater than 1.0 %.
Applications and practical value
- Production quality control: Rapid, repeatable assessment of dimensional stability to support process control and fabric acceptance decisions.
- Process simulation: Useful for correlating accelerated laundering behaviour with specific domestic or industrial laundering options and wet‑processing operations.
- Material evaluation: Screening fabrics (knits and wovens) for relaxation and shrinkage tendencies before garment construction.
Who should use this standard
- Textile manufacturers and mills performing in‑line quality checks
- Garment and technical textile producers assessing fabric behavior after laundering
- Test laboratories correlating production tests with standard laundering procedures
Related standards
- ISO 6330 - Domestic washing and drying procedures for textile testing
- ISO 5077 - Determination of dimensional change of textiles (reference method)
- ISO 3759 - Marking and specimen preparation (referenced for correlated workflows)
Keywords: ISO 23231:2025, dimensional change, textile testing, accelerated machine method, fabric shrinkage, laundering simulation, production quality control, benchmark distances.