ISO 20932-3:2018

Overview

ISO 20932-3:2018 - Textiles - Determination of the elasticity of fabrics - Part 3: Narrow fabrics - specifies standardized test methods to measure the elasticity and related properties of narrow fabrics (e.g., trims, bindings, webbings, straps). The document defines two complementary test methods: Method A for product quality assurance (repeated cycling) and Method B to assess product performance in use (single-cycle sequence). The standard supports consistent, repeatable measurement of force, elongation, recovery and permanent deformation for narrow textile constructions.

Key topics and requirements

• Scope and definitions: clear terms for narrow fabric, elasticity, elongation, permanent deformation, force decay, cycle, etc.
• Test principles:
  • Method A - cyclic extension to a specified force for a number of cycles to evaluate force decay, recovered elongation and permanent deformation.
  • Method B - single-cycle extension to specified force and elongation to mimic in-use performance.
• Apparatus:
  • Constant-rate-of-extension (CRE) tensile testing machine with force and elongation recording (accuracy at least class 1 per ISO 7500-1).
  • Line clamps (convex 3 mm radius) sized to specimen width (recommended (70 ± 6) mm) and pneumatic grip recommended to prevent slippage.
  • Data acquisition at a minimum frequency of eight samples per second when using electronic recording.
• Machine performance:
  • Capable of extension rates from 20 mm/min to 500 mm/min (±10%).
  • Gauge length adjustable typically between 100 mm and 250 mm (±1 mm).
  • Metrological confirmation in accordance with ISO 10012.
• Sampling & specimen prep:
  • Minimum of five specimens per set, cut in the length direction; conditioning in a tension-free state for at least 20 hours per ISO 139.
  • Guidance on removing leading material (e.g., discard first 500 mm, reject 300 mm between specimens).
• Measured outputs: force at specified elongation, maximum force, maximum extension, force decay (time and exercising), elastic recovery and permanent deformation. Annexes provide example cycling graphs and clamping details.

Applications and users

ISO 20932-3 is used by:

• Textile manufacturers and converters producing narrow fabrics, webbings and trims.
• Quality control and testing laboratories validating elastic performance and batch acceptance.
• Product designers and R&D teams selecting materials for elastic behavior in garments, safety harnesses, medical straps, sportswear and technical textiles.
• Procurement and compliance teams who require standardized test evidence of in-use performance.

Practical uses include routine quality assurance, end-of-line testing, material comparison, and performance verification under cyclic loading or specified service conditions.

Related standards

• ISO 20932 series (other parts)
• ISO 139 (conditioning atmospheres)
• ISO 10012 (measurement management)
• ISO 7500-1 (verification of tensile machines)
• ISO 22198 (fabric width/length determination)
• (Based on EN 14704-3)