Twist and linear density coefficient of variation-length curves of polyester/cotton yarns spun by different processes

The coefficients of variation-length curves for yarn twist and linear density have been determined for polyester/cotton yarns spun by ring, rotor, and friction processes as a function of blend proportion, yarn twist, and yarn linear density. The influence of each of these parameters on twist and linear density irregularity is described according to the spinning process. The coefficients of variation length curves can be mathematically represented with sufficient accuracy by a polynomial expression including first-and second-order terms.