ISO 17751-1:2023

Overview

ISO 17751-1:2023 - Textiles: Quantitative analysis of cashmere, wool, other speciality animal fibres and their blends - Part 1: Light microscopy method specifies a standardized light microscopy (LM) procedure for identification, qualitative and quantitative analysis of cashmere, sheep wool and other speciality animal fibres (e.g., alpaca, camel, yak, mohair, angora, rabbit) and their blends. Applicable to loose fibres, intermediate products and finished textile products, this second edition updates specimen preparation, sampling, conditioning and calculation methods to improve reproducibility in fibre-content testing.

Key topics and technical requirements

• Scope and applicability: LM method for loose fibres, slivers, yarns, woven and knitted fabrics.
• Principle: Longitudinal optical images of fibre snippets are used to identify fibre types by surface morphology; counts and diameter measurements are used to calculate mass fractions using measured diameters and known fibre densities.
• Apparatus & reagents:
  • Projection microscope or visual microscopic image analyser (examples listed), with calibration using a stage micrometer; objective/ocular system capable of high magnification (document cites at least 500× on screen).
  • Liquid paraffin (refractive index 1.43–1.53) and cutting tools (scalpels/double blades) for specimen prep.
• Sampling & conditioning: Lot sample → laboratory sample → multiple test specimens; conditioning per ISO standard atmospheres (ISO 139 referenced).
• Specimen preparation: Procedures for loose fibres, sliver, yarn, woven and knitted fabrics, including pre-treatment (decolouration/Soxhlet extraction when required) and requirements for replicate specimens and re-testing if discrepancies occur.
• Measurement & calculation: Measurement of fibre diameters and counts, use of true density values (Annex D) and formulae for mass-fraction calculation; reporting requirements and test report content.
• Annexes: Normative drawing of sampling (Annex A), decolouration guidance (Annex B), micrographs/surface morphology for fibre identification (Annex C) and fibre densities (Annex D).

Practical applications and users

ISO 17751-1:2023 is intended for:

• Textile testing laboratories and quality-control teams verifying fibre content claims (cashmere/wool blends).
• Manufacturers and brands seeking standardized, defensible fibre-content analysis for product specification and labeling.
• Certification bodies, import/customs laboratories and forensic analysts investigating fibre authenticity or mislabeling.
• Research and development groups comparing LM with complementary methods (e.g., SEM) for difficult-to-identify samples.

Using this standard improves consistency in fibre identification, supports traceability and helps detect adulteration or mislabeling in high-value animal-fibre products.

Related Standards (if applicable)

• ISO 139 (conditioning and standard atmospheres) - normative reference used by this method.
• Other parts of the ISO 17751 series (see ISO website for a complete listing) and complementary microscopy methods (SEM) referenced in the standard’s introduction.