Application Of New Oxidation And Reduction System In Sulfur Dyes Dyeing

Nowadays, around the world, excessive amounts of sodium sulfide used for 90%sulfur dyes staining. The excess sodium sulfide will produce large numbers of sulfur-containing wastewater. The direct emissions of the sulfur-containing wastewater,not only pollute the water, has a harmful effect on the natural biological, and there are hydrogen sulfide released during the dyeing process, which destroy operators’ health.Therefore, the research of using a new type of environmental reduction system to replace sodium sulfide has become the major direction of sulfur dyes dyeing.For special sulfur dyes as sulphur red brown, the fabric dyed with sulphur red brown will occurring a phenomenon of discoloration since the oxidation, after placed in the air for a long time. It is means during the oxidation process, the dyed fabric has not been fully oxidized lead to a change of color and color shade of the fabric. This is the biggest problem faced by sulphur red brown staining which limited the development of the dyes,so we need to explore a new kind of oxidation system which make the fabric being oxidized full in one step, and reduce the additional oxidation in later storage process.The paper using sodium borohydride, thiourea dioxide, glucose and many others reducing agent as reduction system, compared with traditional sodium sulfide reduction system. Using center composite experiment to design experiment scheme, the optimal reduction system can be analysied by testing dyed fabric properties, fabric abrasion performance and strength performance. In order to verify the results, the fabric was being dyed with sulfur black using the optimal reduction system, the optimal, stable, feasible and efficient environmentally reduction system obtained.For oxidation system, the fabric being dyed with sulfur red brown using sodium sulfide as reducing agent, then the dyed fabric being oxidized with different oxidation system, the color and color shade of the dyed fabric are tested after placed in the air for different time. The influential factors in the sulphur red brow dyeing process are designed through the central composite experimental method, chose color shade and dyeing depth of the fabric which placed in the air for three weeks as mean evaluation indictor, the optimal oxidation system is obtained through the analysis of the data.As results, two environment-friendly reduction systems, sodium borohydride reduction system and thiourea dioxide reduction system are obtained, and a oxidation system, ammonium persulfate oxidation system which apply to sulphur red brown is obtained through the experiment.