The Alkali Desizing of Woven Cotton Fabrics

The alkali metal hydroxides LiOH, NaOH and KOH have been studied in the desizing of woven cotton fabrics under different treatment conditions. The % fabric weight loss, the TEGEVA rating on the desized fabric, the effect of desizing bath pH and the molarity of the alkalis to the desizing results, and the starch removal rate of the treatments was studied. It was found that the removal of starch size from the warp yams of the woven cotton fabric is not only bath pH dependent, but also depending on the nature of the alkali that used, in that NaOH has the best desizing ability among the others. In addition, the temperature of the desizing bath is the most important in order to obtain a good desizing result. Although alkali desizing can improve the water absorption and the whiteness of the grey cotton fabric, it is not good enough for use in subsequent coloration processes.