Standardized Protocol
Standardized testing procedures published by the International Organization for Standardization dictate methods for determining the elasticity of narrow and wide woven or knitted fabrics under cyclic loading. ISO 20932 1 governs the determination of elastic stretch, unrecovered elongation, and residual deformation using constant rate of extension testing apparatus. The standard applies to all narrow and wide elastic fabrics containing elastomeric fibers or textured yarns, stopping when rigid unstretchable fabrics or nonwoven webs are evaluated.
Test protocols specify precise jaw distances, extension rates, and cycling parameters to simulate wear conditions.
Test Procedure
Specimen strips undergo repeated elongation to defined force limits or extension percentages within a tensile testing machine. Force-displacement curves record immediate elastic recovery, delayed recovery, and permanent set. Pre-conditioning under standard testing atmospheres ensures reproducible test results.
Parameter Control
Testing speed and clamping pressure must remain uniform to prevent specimen slippage or jaw breaks. Lowering extension speeds alters stress relaxation rates in elastomeric yarns. Test reports detail peak force, stretch percentage, and residual strain after specified recovery periods.
Commercial Compliance
Apparel brands mandate compliance with ISO 20932 1 to benchmark stretch performance across global supply chains. Test metrics establish clear criteria for fabric qualification in compression garments and activewear. Laboratory accreditation requires strict adherence to standardized specimen preparation and calibration protocols.
