ISO 1833-16:2019

Overview

ISO 1833-16:2019 - Textiles - Quantitative chemical analysis - Part 16 defines a laboratory method for determining the mass percentage of polypropylene in textile blends using xylene as the solvent. The method measures polypropylene content after the removal of non‑fibrous matter in mixtures of polypropylene with a wide range of natural and synthetic fibres (wool, silk, cotton, viscose, cupro, modal, lyocell, acetate, triacetate, polyamide, polyester, acrylic, glass, elastomultiester, melamine and polyacrylate).

Key topics and requirements

• Principle: Dissolve polypropylene from a known dry mass of the specimen in boiling xylene; collect, wash, dry and weigh the insoluble residue; calculate polypropylene content by difference.
• Scope: Applicable only to mixtures of polypropylene with the specified fibres after removal of non‑fibrous matter.
• Reagents: Xylene (boiling range 136–145 °C) and light petroleum as described in ISO 1833-1. Safety precautions for xylene use are required.
• Apparatus: Round‑bottom flask (≥200 ml), reflux condenser suitable for high‑boiling liquids, heating mantle for xylene boiling point, and hot‑weighed filter crucible.
• Test procedure: Follow ISO 1833-1 general procedure; use specified volumes of xylene and light petroleum with repeated boiling, decanting and washing steps; alternatively, equivalent hot‑extraction apparatus (e.g., as in ISO 1833-21) may be used.
• Calculation: Use ISO 1833-1 general calculation rules. Density correction factor d = 1.00 (d = 1.01 for melamine and polyacrylate).
• Precision: For homogeneous textile mixtures, results have 95% confidence limits within ±1 percentage point.

Applications and users

• Quality control and textile testing laboratories performing quantitative fibre composition analysis.
• Textile and yarn manufacturers verifying blend content for product specifications and labeling.
• Regulatory bodies and conformity assessment organizations checking compliance with labelling and trade standards.
• Research institutions and forensic fibre analysts needing a standardized chemical method for polypropylene quantification.

Benefits include a reproducible, internationally recognized procedure for accurate polypropylene quantification in blended textiles, enabling consistent product classification, compliance, and quality assurance.

Related standards

• ISO 1833-1 - General principles and calculation procedures for quantitative chemical analysis of textiles.
• ISO 1833-21 - Alternative hot‑extraction methods for similar fibre mixtures (referenced for equivalent apparatus and procedures).
• Other parts of the ISO 1833 series cover different fibre combinations and solvent methods.

Keywords: ISO 1833-16, polypropylene, xylene, textile analysis, quantitative chemical analysis, fibre composition, fiber blend testing, textile laboratory methods.