Thermodynamic Analysis of Hydrolyzed Polyurethane Filament Failure during Dyeing
Hydrolytic polyurethane breakdown during high-temperature dyeing occurs via acid-catalyzed ester cleavage, requiring polyether backbones and strict pH control.
ISO 13934 Tensile Loss
Standardized Assessment
Strength degradation of woven fabrics measured after chemical or mechanical processing is quantified using standardized strip or grab testing protocols. Specifically, ISO 13934 tensile loss measures the decrease in maximum breaking force when a fabric specimen is pulled to rupture. This value is used by quality assurance laboratories to evaluate the damage caused by bleaching, resin finishing, or industrial washing.
Fibre Degradation
Chemical treatments often weaken the cellulose or synthetic polymer chains and lead to a drop in fabric strength. Resin finishing of cotton for wrinkle resistance creates crosslinks that restrict chain movement, causing a loss in elasticity. Acidic conditions in the dye bath can also hydrolyze the polymer chains.
When these processed fabrics undergo standard tensile tests, they fail at lower forces than the untreated grey goods.
Testing Procedure
Execution of this measurement involves mounting a fabric specimen of specific dimensions between the clamps of a universal testing machine. The machine applies a constant rate of extension until the specimen breaks. Load and elongation are recorded continuously by the testing software.
Comparative analysis of the pre-treatment and post-treatment results yields the percentage of strength reduction. Accurate alignment of the specimen is necessary to avoid premature tearing at the clamp jaws.
Performance Benchmark
A strength reduction exceeding twenty percent indicates unacceptable degradation during the industrial finishing stage. Manufacturers set strict limit thresholds for this tensile metric to ensure the product meets durability standards for workwear.