NH3 and NaOH/NH3 treated cotton fabrics are processed with hot water at 100 and 130°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 NH3 treatment increases a little after hot water processing and washing shrinkage is considerably controlled. Although the dyeing rate decreases with the NH 3 treatment, it increases a little with subsequent hot water processing. In contrast, equilibrium dye uptake decreases with the processing. The mechanical properties of the processed fabrics are evaluated by means of KES shear behavior ( G, 2 HG ) and bending hysteresis ( B, 2HB ). G and 2HG decreased by NH 3 and NaOH/NH 3 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 NH 3 and NaOH/NH 3 . Liquid ammonia has been used to improve the hand of the cotton fabric [1][2][3][4][5][6][8][9][10][11]. Previously, we reported that liquid ammonia treatment induces a change in the fine structure of cotton fibers and influences dyeing [12] and Ks mechanical properties [ 13,14]. Furthermore, we investigated the effect of two-step processes such as NaOH/NH3 and NH3/NaOH. NaOH/NH3 treatment was much more effective at improving the soft hand of the fabric compared with NH3 alone [13,14]. On the other hand, NH3/NaOH improved dyeing properties, though the hand was inferior to the NH3 and NaOH/NH3 treatments [14].In this study, NH3 and NaOH/NH3 treated cotton fabrics are subsequently processed with hot water at 100 and 130°C. We then measure dyeing and mechanical properties and evaluate the effect of hot water on functional properties by means of KES measurements.
ExperimentalDesized, scoured cotton fabric was mercerized under tension and subsequently treated for 2 seconds with NH3 at free dimensions using a practical range (Nisshinbo Co. Ltd.) [12][13][14]. The treated fabric was then processed with hot water at 100 and I30°C in a relaxed state using a Texam Minicolor laboratory-type high pressure dyeing machine (Texam Co., Ltd., Japan).The pretreated fabric was washed twenty times in a home electric washing machine according to the JIS L 1042 G method. Shrinkage was obtained by an average of five measurements. Dry crease angle was measured with a Monsanto crease angle tester in both warp and fill directions ten times each to get an average. Moisture regain and water absorption were measured according to the following procedure: The fabric was impregnated in distilled water for 24 hours and then centrifuged for 20 minutes at 3000 rpm ( W, ). Next, the