Research And Application Practice On Process Of Coloring Burn-Out Printing Of Stretch Denim Fabric

Coloring burn-out process made one of the fiber material in the fabric dissolved using burnt-out agent, while another fiber left was dyed to achieve an unique appearance. Stretch denim fabric coloring burn-out products enjoy bright color, rich concavity, translucent unique style, contributed to adding denim the extra value and to meeting consumer individual demand. In order to obtain the optimum coloring burn-out process conditions for denim,in this paper, the disperse dye and burn-out printing paste has been picked out firstly, then design experiments with the use of controlling variables and orthogonal experiment to study how burn-out mixed printing paste ingredients: burn-out original paste, sodium bisulfate concentration, the amount of agent and baking time, steaming time, washing conditions affect the final coloring burn-out appearance of stretch denim. Because of a an lack of objective assessment of coloring burn-out appearance, this paper finally choose weight difference before and after the final selection, burnt-out grade and K/S values as a coloring burnt-out effect evaluation based on lots of experiments. Through testing, identify the suitable disperse dyes and paste, and how burn-out mixed printing paste ingredients and coloring burn-out technique conditions affect the final coloring burn-out appearance of stretch denim, and the optimum coloring burn-out process conditions for two different fabrics : fabric a and fabric e. The studies have found:(1) Disperse dyes BL red, SF-6G yellow, SF-2G orange, SGF green, C-6B green, SGL blue, HGRL purple can be applied for coloring burn-out technique; T-8 can be used for burnt-out paste.(2) As for fabric a and fabric e, when the original paste concentration was 34%, the smallest irregularity of the color would be obtained and K/S value reached maximum in the coloring burn-out printing. With the increase of original paste concentration the weight loss before and after the burnt-out printing decreased slightly.(3) With the increase of sodium bisulfate concentration, K/S values decreased slowly at first and then decreased rapidly, and finally tends to be stable, which was "inverse S-shaped". With the increase of sodium bisulfate concentration, the weight loss changed slightly. When sodium bisulfate concentration is 20%, the cotton fiber in fabric a have already been broken up completely. When the sodium bisulfate concentration reached 22%, fabric e gets the same results.(4) Glycerol has a slight impact on K/S value, I get a minimum K/S value without glycerol. K/S value gradually increased with the increase of the glycerol concentration. Glycerol concentration had no much influence on degree of burn-out. Penetrant affected weight loss slightly, but could exert deeply effect on K/S value. The suitable Glycerol and penetrant concentration for coloring burn-out printing were about 1%.(5) Baking time has a relatively smaller effect on K/S value and weight loss.(6) Steaming time has a significant effect on K/S value, and a relatively smaller impact on weight loss. With the extension of steaming time, K/S value increases at first then tend to be stable. As for the fabric a, when the steaming time was set 20 minutes, K/S value reached maximum. As for the fabric e, when the steaming time was 30 minutes, K/S value reached maximum. If continue to increase steaming time, K/S value would change slightly.(7) The optimum washing process conditions of coloring burn-out technique for stretch denim contains 1g/L of anti-agent concentration, 50-60 ℃ in temperature, 15 minutes of washing process time.(8) The sodium bisulfate concentration and original paste concentration significantly affect weight loss and K/S value according to orthogonal experiment analysis. While baking time and the steaming time exert less significant effect on weight loss. The concentration of sodium bisulfate effects K/S value most remarkably, while other factors are not. Under both clean and complete as possible to ensure the burnt-out, but also to ensure that the coloring in good premise, for the fabric a, the optimum coloring burn-out process conditions for the original paste concentration is around 34%, while the concentration of sodium bisulfate 16%, baking time 3 minutes, steaming time 25 minutes; for the fabric e, the optimum technique conditions for the original paste concentration is 34%, while the concentration of sodium bisulfate 20%, baking time 5 minutes, steaming time 30 minutes.Finally, the design pattern is made up of the color area and lines, which is applied to practice coloring burn-out process for stretch denim fabric.