ISO 1833-27:2018

Overview

ISO 1833-27:2018 specifies a quantitative chemical analysis method for determining the mass percentage of cellulose fibres (natural or regenerated) in textile mixtures containing cellulose combined with polyester, polyamide, acrylic, wool or elastane. The method uses an aluminium sulfate (sulfate d’aluminium) carbonization treatment to degrade cellulose, leaving the non‑cellulosic residue to be recovered, dried and weighed. The cellulose content is calculated by difference after removal of non‑fibrous matter.

Keywords: ISO 1833-27:2018, textile analysis, quantitative chemical analysis, aluminium sulfate, cellulose fibre content, carbonization method.

Key topics and requirements

• Scope: Applicable to textiles made of mixtures of cellulose fibres with polyester, polyamide, acrylic, wool and elastane.
• Principle: Cellulose is degraded by an aluminium sulfate/glycerol solution plus thermal treatment; the remaining residue is washed, dried and weighed to determine non‑cellulose fraction.
• Reagents: Aluminium sulfate octadecahydrate (51.0–57.5% mass fraction), glycerol (>99%), guar gum (>99%).
• Solution composition: 200 g aluminium sulfate, 300 g glycerol, 1 g guar gum, made up to 1 L with water.
• Apparatus & conditions:
  • Heated press plates at (160 ± 2) °C applying (40 ± 10) g/cm² for 5 minutes.
  • Mechanical horizontal agitator (≈250–300 min⁻¹) with ~25 mm amplitude for removing carbonized fibres.
  • Square plastic bottle, ~150 stainless steel balls (≈6 mm), and a standard sieve (mesh 120–150 µm).
  • Ensure wet specimen mass >1.7 × anhydrous mass before carbonization.
• Procedure highlights: soak specimen in carbonization solution, centrifuge or wring to specified wet mass, heat-press carbonize, mechanically agitate with water and steel balls, filter through sieve, dry and weigh residue, microscopically verify cellulose removal.
• Accuracy: For homogeneous mixtures, the method’s 95% confidence limits are within ±1 percentage point.

Applications and users

• Quality control laboratories in textile manufacturing for composition verification.
• Third‑party testing and certification bodies assessing fibre content claims.
• Material R&D and forensic textile analysis where reliable cellulose quantification is needed.
• Useful where a safer, less hazardous alternative to strong acid dissolution is preferred; the carbonization method can improve lab safety and environmental conditions compared with concentrated-acid methods.

Related standards

• ISO 1833-1:2006 - general principles for quantitative chemical analysis of textiles.
• ISO 1833 series - other parts cover different fibre combinations and analytical techniques.

Note: Follow all applicable health, safety and environmental regulations when handling reagents and performing thermal treatments.