Single-phase ink-jet printing onto cotton fabric

The current commercial application of ink-jet reactive inks to cotton fabrics requires pretreating with pad liquor containing a thickener, urea and alkali prior to printing. In this study, attempts have been made to develop a reactive ink-jet print in a single-phase process by adding an organic salt to the ink formulation and hence removing the need to pretreat fabrics. This approach utilises inks containing both a reactive dye, in this case Procion Red H-E3B, and an organic salt such as sodium formate, sodium acetate, sodium propionate or tri-sodium citrate. The behaviour of a novel reactive ink formulation for ink-jet printing on to cotton fabric was evaluated at different pH vlaues. The results at optimum pH indicated that printed non-pretreated fabrics with ink containing organic salts exhibited a higher level of reactive dye fixation than printed pretreated fabric containing no organic salt ink. The yielded prints demonstrate excellent colour fastness to washing and dry/wet crocking properties. The light fastness of the printed fabrics was improved by adding an organic salt to the ink formulation.