Research On The Suppression Of Sulfur Reducing Cleaning Agents In Polyester Dyeing Process

After the dyeing procedure of the polyester fiber is completed,the floating color on the fiber surface needs to be removed by reduction and cleaning,so as to meet the color fastness requirements of the polyester product.However,traditional reduction cleaning powder or new reduction cleaning agent,are mostly sulfur-containing compounds.The large amount of sulfur-containing wastewater generated in the reduction and cleaning process has an adverse impact on the environment.Therefore,exploring a new process that can eliminate the use of sulfur-containing reducing cleaning agents is of great significance for cleaner production and environmental protection.Based on the in-situ mineralization dyeing technology,this paper explores the non-sulfur dyeing process of polyester that is free of sulfur-containing reducing cleaning agent.The basic idea is: under certain conditions,the mineralization series of additives will be used to mineralize the waste dyes and additives in the fiber surface and residual liquid into small molecules such as carbon dioxide and water,to achieve the goal of improving the quality of the product and reducing the pollution load of discharged wastewater.This process replaces the process of using sulfur-containing reducing cleaning agent to remove floating color on the fiber surface in the traditional process,so it reduces the sulfur content in the discharged wastewater and reduces the adverse impact on the environment.This paper explores the mineralization effect of three common structures of disperse dyes.Under the premise of consistent mineralization conditions,the anthraquinonoid structure dyes have good mineralization effects,and the mineralization efficiency was more than 85%;while the azo structure and the heterocyclic structure of the dye mineralization efficiency was inferior to dyes of anthraquinonoid structure,the mineralization efficiency was between 50%-80%.Through the UV / Visible spectrum test and the chemical oxygen demand test of various reducing cleaning residues,it is concluded that different reducing cleaning agents have different effects on the dyes and have a greater impact on the residual liquid chemical oxygen demand.In contrast,mineralization can destroy the conjugated structure and aromatic structure of the dye molecule,and the chemical oxygen demand of the residual liquid after mineralization is significantly reduced.Through the process optimization,the non-sulfur dyeing process of ordinary polyester knitted fabrics is determined: the amount of dye is X,after the dyeing procedure is completed,reducing the temperature to 90 ° C,and adding the mineralized coupling agent XBD(0.2X);after 5 minutes of circulation,the mineralized coupling agent XYD(2X)is added,keeping for 30 min,drain;adding sodium hydroxide(1g/L)and DL(1g/L)to the bath,keep for 10 min at 70 ?,drain;wash with water,and neutralize.Through process optimization,the non-sulfur dyeing process of suede-like suede is determined: the amount of dye is X,the starting temperature is 40?,increasing the temperature to 120? at 1? / min,and maintaining for 45 minutes,the dyeing is finished;Adding XAO(1g/L)and Na OH(1g/L)to the batn,keep for 20 min at the temperature of 80?,drain;wash for 10 min at 60?;drain;adjust the p H of the bath to 4,add mineralization coupling agent XBD(0.2X)and XYD(2X),keep for 30 min at 85?;wash with water.