A novel application involving printing anionic dyestuffs, namely reactive, direct and acid dyes on cotton as well as 70/30 cotton/wool substrates is fulfilled using a cationic reactant. This technique involves using two steps: the first step is printing with a recipe that includes only the thickening agent and the cationic reactant followed by steaming or thermofixation and eventually washing off. The second step is carried ou dyeing using the anionic dye at specific pH value and temperature. The mentioned sequence ensures the prevention of prints' bleeding on backgrounds and reduces energy consumption required for dye fixation on the bicomponent fabric as well as saving dye and electrolyte amounts that pollute the water effluent. In order to illustrate the union shade with sharp outlines achieved via using this technique, several design applications are carried out using different anionic dyes. All parameters and measurements that may affect the results of this work are discussed in detail, such as: cationic reactant concentration, fixation method of prints, nitrogen content percentage, tensile strength and fastness properties |
