Greener printing of natural colour using microwave fixation

Abstract

Wool fabric has been printed with 2-hydroxy-1,4-naphthoqunione (the main colouring material of henna) using different modes of fixation such as microwave heating, steaming and thermofixation and the effect of printing conditions (dye concentration, pH of printing paste, glycerin concentration, mordant type and thickening agent type) on the colour strength and fastness properties of the printed samples studied. It is observed that the printing paste containing 0.3% dye and 3% glycerin, thickened with CMC, maintained at pH 3 and fixed by microwave heating for 4 min gives the highest K/S value without the need of drying step. The printed samples fixed by the conventional fixation method (steaming or thermofixation) give brownish red shade while those fixed by microwave heating give orange shade. The colour strength and overall fastness properties of the microwave - fixed samples are found to be good and the samples acquire soft handle.