Research On Yarn Tension Control And Yarn Path Planning For Carpet Tufted Machine

The yarn tension is an important parameter involved in the weaving process. Tension is related not only with the fiber type, yarn structure, but also with the other parameters in the configuration of other production processes. The yarn tension significantly influences the quality of carpet, yarn breakage rate and the manufacture efficiency. Taking an example of the ’8+4’ tufted machine, this paper made emphasis studies on the modified Euler formula of the tension control equipments such as the yarn feed roller and the gear-like puller roller. With a lot of theoretical research and analysis with the tension control devices in the tufted machine, a control strategy of the tension control system has been proposed. Main contents are as following:(1) The main factors which influence the loop pile height are got through an analysis of the tufted process. By analyzing the tension control device commonly used design principle, the yarn tension problem of the tufted machine manifested mainly in the yarn surface on the mechanical problems.(2) By comparison loop pile and jacquard yarn systems, the roles of tension control devices are analyzed. Through the theoretical studies on the yarn mechanical problems of the feed roller, thread tube, guide board and gear-like puller roller, the modified Euler formulas have established for the tension devices.(3) The parameters which measure yarn tension’s uneven rate and fluctuations are proposed; analysis about how the feed roller, gear-like puller roller and the guide board impacts on the yarn tension’s uneven rate and fluctuations are done.(4) Through test analysis of the characteristics of the commonly used BCF polypropylene yarn, the mechanism of the yarn tension is got. Dynamic analysis of the variation of the yarn tension when the yarn passes through the feed roller, gear-like puller roller and guide board, the main factors of these tension devices which impact on the yarn tension are got.(5) The yarn path of ’8+4’ tufted machine has been researched and improved. The open loop control system is changed into a close loop one. Tension detection system that uses active feedback tension control has been introduced. The tension control system control strategy is advocated. The tension control plan of the tufted machine is designed based on the adaptive fuzzy PID theory.Through the theoretical research and dynamic analysis of tension control devices of the tufted machine, the modified Euler formulas had been proposed. It can provide the theory basis for the yarn path planning and have instruction functions for the engineer application in the carpet tufted machine.