Determination of slub length of slub yarns based on transformation of ring bobbin

High-precision slub yarns were produced by EJM128K type ring spinning frame which had been equipped with PLC controlled servomotor.By analyzing the transfer function of the control system of slub yarn production,it was asserted that this close loop control system possess the characteristics of stability,precision and rapidity in controlling the parameters of slub length.USTER TESTER5 was used to test the slub yarns produced on the system and the distribution curve of slub length and slub space was attained.The influence of the preset slub length,twist factor,and material types on the deflection of slub length was investigated.These findings offer reference for effective control of slub length and production of high quality slub yarns.