Cotton Ply Twist Multipliers in Continuous Reactive Dyeing
Yarn ply twist multiplier controls intra-bundle pore radius; multipliers above 4.0 cause surface ring-dyeing frosting while values under 3.2 provoke migration.
Fabric Spirality Skewness
Angular Distortion
Geometric misalignment in knitted or woven textiles causes the vertical and horizontal yarns to sit at an angle other than ninety degrees. In fabric spirality skewness, the internal stresses of highly twisted yarns force the material to twist out of plane. The distortion often becomes apparent only after the first laundering cycle when the tension releases.
Calculation Metric
Inspectors calculate the deviation of a side seam or a printed line from a true vertical axis over a fixed distance. Accurate fabric spirality skewness values are expressed as a percentage of the total width. A skew exceeding five percent typically causes visible twisting in finished shirts or leggings.
Assessment occurs on a flat surface to prevent manual tension from masking the underlying defect.
Structural Cause
Use of single jersey knits with unbalanced yarn torque frequently produces this effect. While finishing processes like heat setting can temporarily mask fabric spirality skewness, the distortion often returns during home wash. Selection of plied yarns or alternating yarn directions provides a more permanent solution.
Production speed during knitting also influences the severity of the bias.
Processing Outcome
Cutting patterns from distorted material results in garments that hang unevenly on the body. The instability forces factories to increase waste or accept lower quality ratings.