Cationic Modifier B Modification And Salt Free Dyeing Of Cotton Fabric

In order to overcome the coulomb repulsion,the reactive dye needs to add a large amount of salt and alkali in the process of dyeing cotton fabric,but it will cause problems such as dye hydrolysis,difficult treatment of dyeing wastewater,and causing salinization of the land.Modification of cotton fabric is one of the effective methods to solve the above problems and improve dye dyeing rate.The impregnation method,the padding method,the cold-rolling reactor method,and the steaming method are currently used in the modification.The dipping method is often studied,while the cold-rolling reactor method saves energy.In this paper,the modification of cotton fabrics was mainly carried out by impregnation method and cold-rolling pile method,and the best method and process of modification were found out.Then,the dyeing method was studied by dipping method and cold-rolling pile method,and the reactive dyes of different structures were tested by the final optimum modification and dyeing process,and finally the pilot test was carried out.The contents of the study were as follows: firstly,the effectiveness of the two methods was determined based on the Zeta potential on the modified cotton fabric and the zeta potential on the unmodified cotton fabric.The dye concentration was 3% o.w.f and the dye concentration was 5% o.w.f.It was determined that the cold rolling reactor method had the best modification effect.The optimum modification process of dye concentration of 3% o.w.f was that the modifier concentration was 50g/L,the sodium hydroxide concentration was 20g/L,the modification time was 8h.When dye concentration was 5% o.w.f.the modifier had a mass concentration of 80 g/L,a sodium hydroxide mass concentration of 30 g/L,and a modification time of 8 h.The modified cotton fabric was dyed by two methods of dipping and cold rolling.Preferably,the impregnation method was carried out without salt and low alkali.The best dyeing process of 3% o.w.f.was sodium carbonate mass concentration 1g/L,dyeing temperature 60 °C,dyeing time 60min;dye concentration 5% o.w.f optimal dyeing process was sodium carbonate mass concentration 2g / L,dyeing temperature was 60 ° C and dyeing time was 60 min.Several dyes with different structures were tested by the best modified process and the best dyeing process.The results showed that the dyeing rate of the dyed cotton fabric was higher than the conventional cotton fabric when the dye concentration was 3% o.w.f..The dyeing rate has been greatly improved,and the dyeing rate of cotton fabric after modification was above 94%.For the dye concentration of 5% o.w.f,the dyeing rate of the dyed cotton fabric was improved compared with that of the conventional cotton fabric,and the dyeing rate of the cotton fabric after modification was above 89%.The color fastness to washing and the color fastness to rubbing of the modified dye were similar to those of the conventional dyeing process.The pilot test was carried out on the best experimental procedure obtained in the above experiment.The dyeing rate of the modified dyed cotton fabric was significantly improved,and the K/S value was greatly improved.Although the leveling property was slightly lower than the conventional dyeing process,it was still within the clothing requirements.The fastness of the modified dyed cotton fabric and the conventional dyed cotton fabric were at the same level.At the same time,the modified dyeing process was lower than the conventional process COD value,in line with environmental protection policies.