Degradation Mechanism
Chemical bond cleavage along polymer backbones reduces the average molecular weight and mechanical strength of synthetic textile fibres during thermal processing. Polymer chain scission occurs when heat or ultraviolet light severs covalent carbon-carbon or ester bonds in synthetic yarns. The reaction alters physical fibre properties without changing macro fabric geometry.
Chemical chain scission operates within synthetic polymers like polyester and polyamide, while leaving inorganic mineral fibres unaffected.
Molecular Truncation
Molecular fragmentation cleaves primary polymer chains into shorter segments. As chain scission progresses during wet processing or yarn drying, shorter polymer segments lose inter-chain entanglements necessary for structural strength. Solution viscosity drops proportionally with decreasing molecular weight.
High-temperature Exposure
Drying polyester fabrics at elevated temperatures accelerates thermo-oxidative breakdown inside raw yarn structures. During high-temperature dyeing and stenter heat-setting operations, uncontrolled chain scission decreases fibre elongation before weaving or garment construction occurs. Over-bleaching cotton-polyester blends with active peroxide agents creates free radicals that target polymer backbones.
Finishing plants measure intrinsic viscosity changes before and after bleaching to monitor molecular degradation.
Truncated Network
Truncated polymer networks fail under low mechanical loads, causing sudden fabric tearing in finished garments. When chain scission reduces average molecular mass below critical spinning thresholds, yarn tensile strength drops sharply during normal wear cycles. Inspection teams identify severe molecular cleavage through bursting strength testing on finished fabric rolls.
