Study of Self-twist Distribution Functions in Different Convergence Modes

Twist distribution functions of self-twist yarn are examined by calculating the twist distribution functions of two strands from the nip of self-twist rollers to the convergence point in three different convergence modes. Twist distribution curves of three different convergence modes on the half cycle length are presented by the twist distribution functions. The images show that the self-twist yarn with a phase difference has a lower self-twist peak than inphase self-twist yarn. Thus the existence of a phase difference not only causes a decrease in the self-twist but also a decrease in the length of the weak-twist zone. Furthermore, the value of the phase difference is calculated according to the twist functions of two strands. Compared with the conventional result, that by the method in this paper is closer to the actual length of the zero twist zone.