Effect of yarn, machine and knitting process parameters on the dynamics of the circular knitting needle

Stitch formation during the knitting process is dependent on the dynamic movements of needles. The movement of the needle is subjected to many different factors during loop formation, such as machine, yarn and knitting process parameters. In particular, machine speed, yarn tension and fiber type are the vital parameters of needle movement. This study was conducted in order to investigate the effect of these parameters on needle dynamics during one knitting cycle. High-speed camera technology was used for the first time to collect data regarding needle movement on a circular knitting machine of E 24 and 30” in diameter. The results showed that the needle displacement in both x and y coordination did tend to increase as the yarn tension increased. For all situations, the elastane yarn was an influential parameter on the needle displacement, although the change in its input tension was not a significant parameter. It was also found that during the production with 100% ring cotton, there was a tendency for the needle to follow the cam path when the machine speed was increased from 15 to 20 rpm. Finally, the data obtained for knitting with the textured polyester yarn showed that the needle movement was highly dependent on yarn input tension.