A Study of the Mechanism of Loop Formation on Weft-Knitting Machinery

The effect of input tension and cam setting on fabric quality and plain-knitted loop formation is investigated in detail, using a lubricated viscose staple yarn. It is indicated that the K 1-4 values are not strictly constants, but are variable when a wide range of knitting stiffnesses are studied. An investigation of the mechanism of loop formation shows that the phenomenon of "robbing-back" is the fundamental factor influencing the size of the knitted loop, and that the percentage "robbed-back" (% R.B.) values are predictable under known knitting conditions. This work suggests that % R.B. is dependent solely on the actual tensions that occur within the knitting zone, and that this robbing action is a function of the machine characteristics and is independent of the yarn, assuming identical yarn frictional properties.