EN ISO 1833-24:2011 (identical to ISO 1833-24:2010) is a standardized chemical test method for quantitative fibre analysis of textiles. It specifies a solvent extraction procedure using a phenol and tetrachloroethane reagent to determine the percentage of polyester in binary mixtures of polyester with acrylic, polypropylene or aramid fibres, after removal of non‑fibrous matter. The method is published by CEN/ISO and is intended for laboratory determination of fibre composition (not applicable to coated fabrics).
Key topics and technical requirements
- Scope: Binary mixtures of certain polyester fibres with acrylic, polypropylene or aramid fibres. Not applicable to coated fabrics.
- Reagent: Phenol/tetrachloroethane mixture, mass ratio 6:4. Ethanol used for washing.
- Safety: Reagents are hazardous - work must be carried out in a fume hood with appropriate PPE.
- Sample preparation: Start from dry mass with non‑fibrous matter removed (refer to ISO 1833‑1 general principles).
- Procedure highlights:
- Use a glass conical flask (min. 250 ml, stoppered) and heating apparatus (e.g., thermostatic water bath).
- Add 100 ml of phenol/tetrachloroethane per gram of specimen, shake 10 minutes at (50 ± 2) °C, decant through a weighed filter crucible.
- Repeat with a further 100 ml warmed reagent; transfer residue to crucible and wash twice with 100 ml ethanol.
- Final wash with water, dry, cool and weigh residue.
- Calculation: Determine polyester percentage by difference using the calculation rules in ISO 1833‑1. The density correction factor d = 1.00 for this part.
- Apparatus: Conical flask, heating bath, weighed filter crucible and suction/filtering equipment.
Applications and practical value
- Quality control of textiles and blends to verify label claims (polyester content).
- Incoming inspection for manufacturers and converters to confirm raw material composition.
- Laboratory testing in fibre analysis, textile certification and compliance testing.
- Research and product development when formulating blends or assessing separation methods.
- Forensic and failure analysis where accurate fibre composition is required.
Who should use this standard
- Textile testing laboratories and accredited testing bodies
- Textile manufacturers, converters and brand quality teams
- Material scientists and R&D departments in fibres and textiles
- Certification bodies and regulatory compliance units
Related standards
- ISO 1833-1 - General principles of quantitative chemical analysis of textiles (normative for procedure and calculations).
- Other parts of ISO 1833 cover different solvent methods for other fibre mixtures (see ISO 1833 series for methods specific to polyamide, cellulose, acetate, etc.).
Keywords: EN ISO 1833-24:2011, ISO 1833-24:2010, textiles quantitative chemical analysis, polyester mixtures, phenol tetrachloroethane method, fibre composition analysis, CEN.
