Deformation Analysis
Mechanical measurement in textile testing determines the permanent deformation that remains in a garment after repeated or prolonged stretching. Garments that suffer from excessive fabric growth quickly lose their shape, showing bagging at the knees, elbows, or waist. Testing protocols involve stretching a fabric sample to a fixed extension for several hours and then measuring the change in length after a recovery period.
This value is critical for stretch denim and knitwear where dimensional stability is essential for consumer satisfaction.
Fiber Contribution
Elastic yarns with high recovery reduce the level of fabric growth in finished garments. If the sheath or core fibers lack elasticity, the fabric remains partially extended after the load is removed. This issue is particularly severe in blended fabrics that contain heavy cellulosic fibers.
Finishing Treatment
Heat-setting on a stenter frame helps lock the polymer structure in place and minimizes subsequent growth. Processing temperatures must be controlled to avoid degrading the elastane core. This step ensures that the elastic recovery remains active during laundering.
Quality Standard
Retailers enforce strict limits on growth to ensure their garments do not deform after a few hours of wear. Typical specifications require fabric growth to stay below five percent after multiple stretch cycles. This control is monitored through random sampling of production lots before garment cutting.
