The Study On Relationship Between Tension In Each Process And Yarn Quality On Compact Spinning

The yarn quality was affected by uneven yarn tension which may caused uneven yarn winding density or the worse package appearance on compact spinning in each process. The yarn would break,and the package was too tight if the yarn tension was too high. On the contrary, unwinding process was prone to take off the ring. The piled yarn were delivered and used after twisting. Unstable yarn tension during the double twisting process would affect the yarn qualities. Winding processes were added after double twisting process so that improve yarn quality. It was necessary to study the tension wave range on the influence of the plied yarn quality. It was critical that studying the tension variation law and relationship between yarn tension change and yarn quality index in each process which could control the tension fluctuation and improve the yarn quality. The German Schmidt ZF2-30 and Tensometric tension meter were used to detect the yarn tension fluctuation on compact spinning, winding,folding and double twisting process, the tension variation curve were draw to study the relationship between tension fluctuation and yarn quality index in this paper. By the reason of the wide yarn tension wave range in spinning and winding process,USTER TENSORRAPID type 4 power meter and USTER TESTER testing type 4evenness were used to test the breaking force, breaking elongation, yarn evenness CV and hairiness of the yarns, it was analyzed and studied that spinning speed,winding speed and winding tension influenced on the yarn quality. The relationship between yarn tension and yarn quality were fit by polynomial fitting, the regression equation of spinning speed,spinning tension and yarn quality index were built, and the regression equation of winding speed, winding tension and yarn quality index were built.The results were as follows,Firstly, there were quadratic curve relationships between spinning speed, yarn evenness CV, hairiness and breaking elongation, the greater spinning, the greater yarn evenness CV and hairiness,the lower breaking elongation. There was quadratic curve relationship between spinning speed and spinning tension in spinning process, the greater spinning speed, the greater spinning tension. There was no relationship between spinning speed and yarn breaking force. That is that yarn breaking force were not changed when the spinning speed were improved.The secondly, there were quadratic curve relationships between winding speed,winding tension and yarn evenness CV,hairiness and breaking elongation in winding process. The greater spinning speed and the greater spinning tension,the greater yarn evenness CV, hairiness and elongation at break, the lower breaking elongation. There was no relationship between winding speed and yarn breaking force.The yarn breaking force were not changed when the winding speed was improved.The thirdly,the yarn tension were wave changed over doubling machine speed in merging process. The yarn change law presented the change trend of fast-stability-then quick increased, and the average tension was 5cN.The fourth, the yarn tension fluctuated from 45 cN to 55 cN in double twisting process. The process was added to deal with piled yarn after double twisting process,the tension was improved from 3cN to 83 cN, the yarn breaking force were not changed, but breaking elongation were decreased.For 45 days, breaking elongation of the yarn kept stable after increased rapidly.The Fifth, the tension variation of the single yarn were that spinning tension was highest, the winding tension was higher than the unwinding tension. The spinning speed had the greater affect on spinning tension than traveler number. The double twisting tension was highest for the piled yarn, the doubling tension was lowest, the spinning tension was higher than winding tension. At the same time, winding and doubling caused the worse yarn evenness CV and hairiness, and decreased the breaking force and breaking elongation. The breaking force and breaking elongation of the yarn were rapidly increased after the double twisting, and the yarn evenness were decreased, but the hairiness were increased.