Study On In-situ Mineralization Of Cotton Fabric By Pad Dying

In the continuous production of cotton fabric pad dyeing,the cotton fabric stays in the padding tank and subsequent water washing tank for a short time.In order to remove unfixed reactive dyes,inorganic salts and alkali fixation agents,it needs to be repeated washing,soaping,pickling,such as post-processing.The waste water produced in this process is high in color,complex in composition,and has a lengthy post-treatment process.The problems of drainage,water consumption,and energy cons umption of cotton fabric pad dyeing are very prominent.In order to solve the above problems,this topic applies the in-situ mineralized dyeing technology to the padding process according to the process and characteristics of padding of cotton fabrics.Dyeing auxiliary XY was added in the dyeing process in order to increase the utilization rate of reactive dyes and reduce the subsequent mineralization load and washing pressure.After the steam fixation is completed,in-situ mineralization technology is used to mineralize the waste reactive dyes and surfactants in the treatment bath to decompose carbon dioxide,water and small molecules,effectively reduce the content of pollutants in the discharged wastewater,and reduce the consumption of water for post-treatment washing,so as to achieve clean production.According to the research on the mechanism of dyeing assistant XY,the dyeing assistant XY has a strong affinity with reactive dye molecules and can combine with each other to form a stable micro-suspension.Furthermo re,the dosage of dyeing assistant was optimized,and finally the dyeing assistant XY was added to the fixing bath and the optimal amount was2.0g/L.Adding auxiliary XY to the fixing solution can inhibit the dye from analyzing on the fiber in the alkali stage,which weaken the contact between the reactive dye and the fixing base agent in the initial stage of evaporation,and reduce the hydrolysis of the reactive dye.As the steaming process continues,the degree of moisture absorption and swelling of cotto n fibers increases,and the association of dyes and auxiliary agent gradually"opens",releasing reactive dyes,effectively improving the reaction rate of dyes and fibers,and increasing the utilization rate of reactive dyes.By testing the effect of the d yeing assistant XY on the improvement of dye utilization under different color numbers,the addition of the dyeing assistant XY can save 10%-20%of the amount of dye.Determine the best process para meters for the dyeing process:the dosage of Na₂SO₄ is200-250g/L,the dosage of fixing agent Na₂CO₃ is 25g/L,and the dosage of fixing agent Na OH is 3.0g/L,the steaming temperature is 110°C,and the steaming time is 3min.The best process parameters for the mineralization process:the dosage of in-situ mineralization coupling agent XJS is 1.0g/L,the mineralization temperature is 70°C,and the mineralization time is 15s,during the mineralization,the p H of the mineralization bath is not adjusted and the mineralization is most suitable after a wash.According to the experimental investigation of the subject,the in-situ mineralization pad dyeing technology for dyeing cotton fabr ic can reduce the chromaticity value of the treatment bath by 20%-40%,reduce the COD_Cr value of the treatment bath by about 50%,and achieve the goal of improving the utilization rate of the dye,energy saving and emission reduction.In addition,the physical and chemical properties of in-situ mineralized dyed fabrics are the same as those of traditional process dyed fabrics,such as co lor depth,luster and color fastness.And in situ mineralization has no significant effect on the chemical structure and crystallinity of cotton fibers.This article contains 24 figures,42 tables,73 references.