Optimising knitting process conditions on the basis of controlled robbing-back of yarn

We carried out identification of knitting process conditions during the controlled robbing-back of yarn in the knitting zone of weft-circular knitting machines on the basis of a computer model of the knitting process. The investigations were carried out for needle-raising cams with limited raising height, by negative feeding in the knitting zone, for the classical and Relanit-type knitting techniques. We verified the experimental research results concerned with yarn tensions in the knitting zone and with the sensitivity of the knitted-in yarn's length on the input tension changes with the use of a computer weft-circular knitting machine which was specially designed and built for measuring (a measuring weft-circular knitting machine). The research results indicate that the knitting process could be realised under conditions of controlled robbing-back of yarns in the knitting zone. Controlled robbing-back enabled the knitting process to be optimised, considering the minimum yarn tension in the knitting zone and the minimum sensitivity of the length of the knitting-in yarn on the changes in the knitting process' technological parameters. The constructional parameters of the optimum cam contours for the classical knitting zone and the Relanit-type knitting zone were defined. These parameters are especially important when manufacturing full fashion products, considering the dimension stability which they require.