ISO 1139:2025 Textiles - Designation of yarns

Full title: Textiles – Designation of yarns

Published by: International Organization for Standardization (ISO)

ICS Classification: 59.080.20 – Yarns

Purpose

Provide a standardized and unambiguous system for designating yarn construction using the Tex linear density system, enabling consistent technical communication, testing, and trade across the textile industry.

Scope

Applicable yarn types:

Single yarns

Folded (plied) yarns

Cabled yarns

Multiple wound yarns

Covers:

Linear density (tex)

Number of filaments (for filament yarns)

Twist direction and twist amount

Number of folds or cables

Exclusions:

Fancy and novelty yarns

Textured or bulked yarns

Wrapped or core-spun yarns

Fibre composition, after-treatments, and package type

Designation Principle

Yarn construction is expressed through concise symbolic notation

All linear densities are stated in the Tex system

Notation reflects structural configuration, not material composition

Linear Density System

Linear density expressed in tex or its submultiples

Values may be:

Nominal (commercial specification, subject to tolerance)

Actual (measured by standardized test methods)

Resultant linear density may differ from theoretical values due to:

Twist insertion

Folding or cabling

Processing tension and moisture

Notation Methods

Single-to-Fold Notation

Starts from single yarn linear density

Uses the multiplication sign (×) to indicate folding or plying

Commonly used in yarn manufacturing and specification

Fold-to-Single Notation

Starts from resultant linear density of the final yarn

Uses the solidus (/) to describe yarn composition

Useful for testing, reporting, and finished yarn description

Yarn Construction Elements

Linear density (tex)

Number of filaments (filament yarns only)

Twist direction: S or Z

Twist amount: turns per metre (t/m) or equivalent unit

Number of folds or cables

Applications

Standardized yarn specification for procurement and trade

Technical communication between spinners, mills, and laboratories

Input for machine setting calculations and material planning

Reference framework for quality control and testing reports

Documentation for woven, knitted, rope, fishing net, and technical textile products

Testing Instruments Supporting ISO 1139:2025

Instrument	Function
Yarn Linear Density Tester (Tex/Denier Tester)	Determine actual linear density for compliance with nominal Tex values
Wrap Reel	Prepare skeins of defined length for mass-based Tex calculation
Analytical Balance	Measure yarn mass with high precision
Twist Tester	Measure twist direction and twist level (turns per metre)
Yarn Length Counter	Accurately measure yarn length for density calculations
Conditioning Chamber	Control temperature and humidity prior to measurement
Yarn Inspection Microscope	Verify filament count and yarn structure (supportive use)

Note:

Actual values used in ISO 1139 designation must be obtained using authorized test methods (e.g. ISO 2060, ISO 2061), making accurate and stable instrumentation essential.

Users

Yarn and textile manufacturers

Quality assurance and testing laboratories

Textile engineers and product designers

Procurement and specification teams

Standards committees and textile educators

Related Standards

ISO 1144 – Tex system and linear density nomenclature

ISO 2061 – Twist measurement

ISO 858 – Yarns for fishing nets

ISO 2947 – Nominal linear density series

ISO 1139:1973 – Previous edition

Professional Instrument Manufacturer

Qinsun Instruments is a Professional Instrument Manufacturer, supplying yarn linear density testers, twist testers, wrap reels, analytical balances, and conditioning systems to support ISO 1139:2025 yarn designation and verification. Our solutions help manufacturers and laboratories achieve accurate, repeatable yarn characterization for specification, quality control, and international trade.

Contact us for professional testing solutions and technical support.

2026-01-04 17:13