INVESTIGATION OF THE EFFECT OF CATIONIZATION PROCESS ON WASTEWATER CHARACTERIZATION, PHYSICAL AND FASTNESS VALUES OF COTTON FABRIC

Abstract

Reactive dyeing is the most widely used dyeing method for dyeing cellulosic fabrics in the textile industry. In this study, it was aimed to reduce the environmental impact caused by the use of high salt during the dyeing of cellulosic fabrics with reactive dyestuffs. In this context, a quaternary ammonium based chemical was used for the cationization of cotton fabrics. The usage amount of cationizing agent and flake caustic was determined with the experiments as 50 g/L and 17 g/L, respectively. Conventional and salt-free dyeing of standard fabric and salt-free dyeing of cationic fabric were carried out with 8 different 1% reactive dyestuffs in the laboratory. As a result of dyeing, it was observed that the color strength of cationic fabrics was at least as high as conventional dyeing. Pilot-scale trials were conducted with black color, the most commonly used dye in production. Two different dyeing processes, conventional dyeing of standard fabric and salt-free dyeing of cationic fabric, were carried out using 7% black reactive dyestuff. The findings revealed that cationic fabric has 8.6% darker color than standard fabric. Fastness and strength values were similar for both fabrics. the Total Dissolved Solids (TDS) value of the salt-free dyeing bath was 74.4 % lower than conventional dyeing. Similarly, the conductivity value of salt-free dyeing was 73% and the Chemical Oxygen Demand (COD) value was 27.8% lower when compared with conventional dyeing bath results. At the end of these studies, it has been seen that the same color strength can be obtained with less dyestuff by using the cationization process and the waste water load can be reduced.