Abstract:

In order to improve the physical properties of cotton yarn to adapt to the high speed warp knitting production, the preteratment technology of cotton yarn were studied. Taking three kinds of cotton yarn with different fineness and indigo dyed cotton yarn as the experimental objects, the low temperature starch, low temperature PVA, lipuid-wax and white oil as the pretreatment agent, the influence of 4 kinds of pretreatment agents on sizing ratio, breaking performance and hairiness properties of 4 kinsa of cotton yarn was studied, and the yarn surface was observed by scanning electron microscope. The results show that the low temperature PVA and liquid wax can decrease the hairiness and improve the stuength of cotton yarn. The low temperature starch can improve the hairiness and the sprength, but reduce the elongation of yarn. White oil can cause the decreases of yarn strength and elongation. The change of the surface properties of indigo yarns due to indigo dyeing make them different from the other three kinds of cotton yarns after the pretreatment.

Key words: warp knitting, cotton yarn, pretreatment agent, sizing ratio, hairiness index