ISO 21587-1-2007 PDF

Full title and description

St ISO 21587-1-2007 — Test methods for circular knitted fabrics — Part 1: Determination of mass per unit length and mass per unit area (2007). This document specifies procedures for measuring the mass of yarn per unit length and fabric mass per unit area for circular knitted fabrics, providing guidance to ensure consistent evaluation for quality control, comparison and specification.

Abstract

This standard defines laboratory test methods to determine two related properties of circular knitted fabrics: the mass of yarn per unit length (typically for yarns used in knitted construction) and the mass per unit area of the knitted fabric (commonly expressed in g/m²). The procedures cover specimen preparation, conditioning, measurement equipment, calculation methods and reporting. The aim is to provide reproducible, comparable results used in production control, specification and research.

General information

• Status: Published standard (2007)
• Publication date: 2007
• Publisher: International Organization for Standardization (ISO) — adopted national editions may be published by national standards bodies
• ICS / categories: 59.080.01 (Textiles — Knit fabrics)
• Edition / version: Edition 1 (2007)
• Number of pages: Typically 8–12 pages (varies by publisher layout)

Scope

This part of ISO 21587 specifies methods for determining the mass per unit length of yarns and the mass per unit area of circular knitted fabrics. It applies to circular knitted fabrics made from one or more yarn types regardless of fibre composition, stitch construction or finishing, where these measurements are required for quality control, specification or laboratory testing. The standard does not cover woven fabrics, non-knit textile structures, or methods for thickness, density or dimensional stability unless specified by referenced test conditions.

Key topics and requirements

• Preparation and selection of test specimens from circular knitted fabric, including cutting and orientation.
• Conditioning of specimens at specified temperature and humidity prior to weighing.
• Measurement of yarn mass per unit length: techniques for extracting yarn samples or calculating from known yarn counts and fabric geometry.
• Measurement of fabric mass per unit area: precise cutting of specimen area and accurate mass determination on calibrated balances.
• Calculation methods to derive g/m and g/m² values, including formulae and unit conversions.
• Rounding rules, number of test replicates and statistical reporting of results (mean, range, repeatability).
• Reporting requirements: specimen description, test conditions, apparatus used, results and any deviations from the method.

Typical use and users

Manufacturers of knitted textiles, textile laboratories, quality control technicians, product developers and specification writers commonly use this standard. It is used to verify that production meets specified fabric weight and yarn consumption targets, to compare materials, to support product labelling (e.g., fabric weight classifications), and in research and development for material selection and process optimization.

Related standards

Related standards include other ISO and national standards on knitted fabric testing such as methods for dimensional stability, thickness, tensile properties, stitch density, and loop length. It is often used alongside standards that specify conditioning atmospheres, balance calibration and general textile test methods for consistent laboratory practice. ISO standards for textile vocabulary and sampling may also be referenced.

Keywords

circular knitted fabric; mass per unit area; areal density; g/m²; yarn mass per unit length; fabric weight; textile testing; specimen conditioning; ISO 21587-1; textile laboratory methods

FAQ

Q: What is this standard?

A: ISO 21587-1-2007 is a test-method standard that specifies how to determine the mass per unit length of yarn and the mass per unit area of circular knitted fabrics.

Q: What does it cover?

A: It covers specimen selection and preparation, conditioning, measurement procedures, calculations and reporting conventions to obtain reproducible measurements of yarn and fabric mass for circular knitted fabrics.

Q: Who typically uses it?

A: Textile manufacturers, independent testing laboratories, quality assurance personnel, product developers and standards committees use it for production control, specification and material comparison.

Q: Is it current or superseded?

A: The document referenced is the 2007 first edition. Users should verify with their national standards body or ISO catalog for any amendments, confirmations, or later revisions that may supersede or update the 2007 edition.

Q: Is it part of a series?

A: Yes — it is Part 1 of ISO 21587, which addresses test methods for circular knitted fabrics. Other parts in the ISO 21587 series (if published) cover additional test methods or specific properties; confirm the series contents with the ISO catalog.

Q: What are the key keywords?

A: Circular knitted fabric, mass per unit area, yarn mass per unit length, g/m², textile testing, specimen conditioning.