Study on the Skewness of Single Jersey Circular Knit Fabrics. I. Effects of Twist Multiplier and Twist Direction of Knitting Yarn

Circular knitting machines are most commonly used to manufacture single jer- sey fabrics because of their high productivity and low costs. However, the knitted fabric exhibits skewness due to factors such as the large number of feeders, properties of twisted spun yarn, and cylinder rotating speed. The course skewness, which is especially promi- nent in the wale direction of plain stitch, causes fabric distortion and as a result, the dis- torted fabrics are unacceptable in appearance and for sewing purposes. In this work, the reasons for the skewness and their effects on the knitted fabric have been experimentally studied. The results show that course skewness is prominent and primarily caused by yarn twist. The effect of the twist direction of the knitting yarns was also studied. It was shown that the Z-twist yarns incline perpendicular to the horizontal direction of the fabric while the S-twist yarns incline in the opposite direction. This could reduce the course skewness as the feeder skewness is counterbalanced.