Tension control system design for warping machines

Warp preparation process is an important preparation process both in weaving and in warp knitting as it directly affects the quality of the fabric to be produced. Control systems used in warping machines should be developed even further with increasing production speeds to protect fabric quality and even improve it. Yarn tension control presents a great importance in this context. Especially in sectional warping machine, all warp sections have to be wound side by side at the same length and tension. Tension changes with respect to bobbin diameter cause warp sections to be wound at different diameters and lengths and deteriorates warp preparation quality. In this thesis, yarn tension change with respect to bobbin diameter is investigated with different yarn types, numbers, bobbin shapes and unwinding speeds and yarn tension deviations are evaluated in terms of short, medium and long period tension changes. Based on this evaluation, performance of a feedback tension control system developed by using a single bobbin creel unit and a 2 units winding machine. It is shown that short, medium and long tension deviations are prevented and kept with in ±1 cN limits. In this way, it became possible to prevent even a long term tension variation of 20 cN with Ne10/1 yarn and at 880 m/min unwinding speed.