Heat Setting Effectiveness in Synthetics
topic
Heat setting effectiveness is measured by subjecting heat-set polyester or nylon fabrics to boiling water or steam relaxation after marking, comparing post-relaxation dimensional change against that of un-heat-set controls; differential scanning calorimetry can quantify crystallinity changes induced by heat setting as a complement to dimensional testing.
Role
Confirms that heat setting temperatures and dwell times have permanently stabilised the thermoplastic polymer network in synthetic fabrics, validating that subsequent dyeing, finishing, and garment use will not introduce additional thermal shrinkage or distortion.