Design And Development Of Efficient Eco-washing Processes For Knitted Cotton Fabric With Reactive Dyes

As a traditional pillar industry of the national economy,the textile printing and dyeing industry occupies an important proportion in the total national economy,and is also an important industry for people’s livelihood.It plays an important role in promoting employment,stimulating market vitality,accelerating the urbanization process and promoting economic development.Textile printing and dyeing industry is high energy consumption,high pollution industry,its wastewater discharge ranked fourth in the domestic industry,more than half of the industrial wastewater from textile printing and dyeing industry,under the increasingly severe environmental regulation,printing and dyeing enterprises only exploring sustainable green road,reduce the energy consumption and wastewater of printing and dyeing enterprises,to achieve new development.Therefore,the application and development of new soaping technology and soaping agent are very important.Firstly,four different ionic types of soaps,two biodegradable surfactants as detergent AIDS and four reactive dyes,C.I.were used in this study.Reactive red 239,C.I.reactive red 120,C.I.reactive blue 19 and C.I.Reactive black 5,which has different types and different amounts of reactive groups,the soaping process of these four dyes was optimized.The differences of molecular structure and active group of dyes were analyzed according to the dyeing rate and fixation rate.The soaping process of each dye under a single soaping agent was determined by orthogonal experiment,and the relationship between the temperature,time,p H,dosage of soaping agent and dye structure was explored.The composition of enzyme soap was verified under high temperature and strong alkali conditions,and the p H of four soap detergents and anti-adhesion were measured.The surfactant octyl glucoside and cardanol polyoxyethylene ether were selected as additives for the compound,in the optimized process of soap,analysis of the p H of soap solution,soap agent performance,dye structure characteristics on soap washing.According to the absorbance value of residual liquid,the color fastness of the fabric after soap washing,the stability,foaming ability,permeability of the soap washing agent,and the COD value of residual soap after soap washing,determine the best soap washing process for each dye and the amount of compound soap detergent.The experimental results show that :（1）the dye dye dye and fixed rate reflect the direct and reactive group reactivity.Active blue 19 has the strongest directness,and the rest are active black 5,active red 120,and active red 239 in order.（2）The soapping effect of enzyme soap under inactivation and strong alkali conditions is similar to that of tap water under the same p H,so the main component of enzyme is enzyme,without other additives.（3）Each single soap agent has certain anti-staining performance and can be used as the main component of soap agent.（4）The soaping process of the optimized single soap agent can reduce the soaping temperature,but the floating color removal rate is not as good as the current soap agent.（5）Compared with single soap,compound soap has improved the color fastness and floating color removal.Moreover,it has certain advantages in alkaline resistance and foaming soaps’ permeability,and the RESIDUAL LIQUID COD of soaps is significantly reduced.（6）The best compound soap and soap washing process of each dye was: C.I.black 5 dye,soap agent 7（soap agent DM-1543: octyl glucoside =5:4）soap washing process :0.9 g/L,80 ℃,15 min.Dry rubbing fastness 4,wet rubbing fastness 3;C.I.Active blue 19,soap agent 3（low temperature soap agent: cardanol polyoxyethylene ether =3:5）soap washing process :0.8 g/L,70 ℃,20 min.Dry rubbing fastness 4,wet rubbing fastness 3;C.I.Active red 239,soap 1（enzyme soap: cardanol polyoxyethylene ether =4:1）soap process :2.5 g/L,70 ℃,15 min.Dry rubbing fastness 4,wet rubbing fastness 3-4;For C.I.reactive red 120,the most suitable soap was soap detergent 1（enzyme soap: cardanol polyoxyethylene ether）=（6:1）.The soap process was 3.5 g/L,70 ℃,15 min.Dry rubbing fastness4,wet rubbing fastness 3-4.The soaping effect of the compound soap agent is similar to that of the current soap agent,but it can reduce the soaping temperature,effectively reduce the COD content in wastewater,achieve energy saving and emission reduction,reduce production costs for enterprises,and improve production efficiency.