Structural Distortion
An invisible, internal torque in a fabric’s yarn structure remains dormant until the material is laundered. This condition, known as latent dimensional skew, is caused by high tension during knitting or yarn spinning, which twists the loop structure out of its natural, relaxed state. When the fabric is wet out, the yarns relax, causing the garment seams to twist and distort.
This defect is a major quality issue in single jersey knitwear, often causing garments to become asymmetrical and unwearable after a single domestic wash cycle, resulting in high returns.
Tension Release
Water and heat act as catalysts that allow the locked-in stresses to escape. During wash cycles, the continuous agitation releases the energy stored in the twisted yarns, and the fabric structure twists to resolve the internal forces. This movement manifests as latent dimensional skew, twisting side seams to the front or back of the garment.
The effect cannot be ironed out because the yarn geometry itself has shifted.
Testing Routine
Standardized laboratory washing tests measure this potential twisting before garments are cut and sewn. Technicians wash fabric panels three times and measure the angle of distortion against the original grain line to calculate the latent dimensional skew percentage. If the twist exceeds the maximum five percent limit, the batch is rejected.
This proactive step prevents the processing of unstable fabrics.
Mitigation Strategy
Finishing mills use stenters and fabric compactors to relax the fabric before cutting. Adjusting the twist-liveliness of the yarn during spinning also reduces the torque that leads to latent dimensional skew. Combining s-twist and z-twist yarns in the knit structure is another way to balance the forces.
These methods ensure the finished garment retains its correct shape after use.
