Colourfastness Properties of Tesu Dyed Silk

Abstract

Colour fastness of fabric is very important aspect as end use of fabrics depends on this property. A study was conducted toinvestigate the colour fastness properties of silk fabric dyed with Tesu flower dye. The dye was extracted with fermentationtechnique and silk fabric was dyed using optimized conditions. Different natural mordants were used to study the effect oncolourfastness. The dyed fabric samples were evaluated for colour fastness to washing, rubbing, light and perspiration usingthe methods prescribed by the Bureau of Indian Standards. On the basis of different shades obtained four natural mordantsviz., amla fruit, pomegranate rind, mango bark and mehandi leaves were selected. The results revealed that 10 and 25percent concentration of each mordant was selected for light and dark shades. Simultaneous and post mordanting werefound to be better than pre mordanting method. It may be due to the reason that simultaneous and post mordanting helped inbetter fixation of dye and superfluous dye material might have stripped out. The washing fastness grades for colour changeranged from 4-5, whereas from 4-4/5 for colour staining with all the four mordants. The light fastness grades for all thesamples ranged from 4-4/5 grades for colour change as well as colour staining. The perspiration fastness grades for colourchange as well as colour staining ranged between 3/4-4/5 for both acidic and alkaline perspiration for all the samples. Therubbing fastness grades for colour change ranged between 4-4/5 for both dry and wet rubbing. The grades for colourstaining were also between 4 and 4/5 for dry and wet rubbing for all the conditions. On the basis of overall fastness rating itwas concluded that the colour fastness of the dyed samples improved considerably after mordanting.