Determining Polymeric Fibre Moisture Regain Using Gravimetric Oven Drying Methods
Gravimetric oven drying determines accurate polymeric fibre regain by measuring dry mass after removing volatile moisture at specified temperatures.
Polyurethane Elastane
Fibre Composition
High molecular weight synthetic block copolymer chains form this synthetic elastomer. Manufacturers produce polyurethane elastane through the reaction of diisocyanates with long chain polyols to create segmented structures consisting of rigid hard segments and flexible soft segments. These segments align during the extrusion process into monofilaments or multifilament yarns.
The material demonstrates high extension capability coupled with rapid recovery to original dimensions.
Elongation Behaviour
This material property permits fabrics to stretch significantly under low tensile loads. Quality control laboratories assess the force required to reach specified elongation percentages compared to the force recorded during retraction. Deviations in these values indicate inconsistent polymerization or improper heat setting during the finishing stage.
Thermal Stability
Heat sensitivity dictates the processing window for synthetic stretch blends. Fabrics containing these filaments lose elastic properties when exposed to temperatures exceeding the threshold established for specific grades. Industrial dryers and commercial steam presses require temperature controls to prevent permanent damage to the structural integrity of the polymer.
Solvent Resistance
Chemical exposure affects the longevity of the filament in finished apparel. Exposure to chlorine compounds in pool water or bleach causes degradation of the polymer chains, resulting in yellowing and premature breakage. Manufacturers utilize protective finishes or additives to mitigate these environmental impacts within the constraints of intended end use.