Effect of hot water processing on dyeing and mechanical properties of cottons treated with liquid ammonia and sodium hydroxide

NH3 and NaOH/NH3 treated cotton fabrics are processed with hot water at 100 and 130 degrees C, and excellent shrink resistance is obtained with the processing. The crystallite form is transformed from cellulose III to cellulose I. Crystallinity decreased by the NH, treatment increases a little after hot water processing and washing shrinkage is considerably controlled. Although the dyeing rate decreases with the NH, treatment, it increases a little with subsequent hot water processing. Tn contrast, equilibrium dye uptake decreases with the processing. The mechanical properties of the processed fabrics are evaluated by means of KES shear behavior (G, 2HG) and bending hysteresis (B, 2HB). G and 2HG decreased by NH3 and NaOH/NH3 show almost no change after hot water processing, while B and 2HB, especially the latter, decrease considerably with the hot water processing after treatment with NH3 and NaOH/NH3.