Influence of Controlled Weft Yarn Tension of a Single Nozzle Air-Jet Loom on the Physical Properties of the Fabric

Control technology is being applied in different industries including textiles. The use of open loop control in dying machines and closed loop control in the let-off motion mechanism of looms are conventional. In this study, a weft yarn tension controller was implemented in a single nozzle air-jet loom for controlling the weft yarn tension variations during weft insertion. The effective parameters on weft yarn tension were introduced by studying the weft yarn equation of motion. Experimental results show that the mechanical brake force has the major effect on weft yarn tension. Thus, the required actuator was designed on the basis of the mechanical brake being controlled by a stepper motor. The PID (proportional + integral + derivative) controller was used to control weft yarn tension. The fabric samples were woven with and without controlled weft yarn tension and their physical properties were measured. The results show that control of the weft yarn tension decreased the coefficient of variation (CV%) of the physical properties of the fabric considerably.