EFFECTS OF SELECTED MORDANTS ON THE APPLICATION OF NATURAL DYE EXTRACTED FROM THE PODS OF PITHECELLOBIUM JIRINGA SEEDS

Natural dyes can be extracted from various sources such as flowers, barks, leaves, roots, wood or with other biological sources like animals, lichens or fungi. The usage of natural dyes requires application of mordant in order to increase the affinity of the colour fastness between the dye and fabric, thus enhancing the colouration of the natural dye. The colouring potential of natural dyes extracted from the pods of Pithecellobium jiringa has been studied against selected mordants such as potassium dichromate and copper (II) sulphate. Dyeing procedure for the application of natural dye onto the fabrics were done by using three different mordanting techniques which are premordanting, simultaneous mordanting and post mordanting respectively. Evaluation of the colour fastness on the dye properties was assessed by evaluating the K/S ratio, on the absorbance of wash off colour strength of dye from the cotton fabric. Copper (II) sulphate showed as the best mordant towards the natural dye extracted from the pods of P. jiringa with the least value of K/S ratio 2.8x10-6 that indicates low degree of dye bleeding from fabric, while the highest value for K/S ratio is 1.08x10-6 was observed with simultaneous mordanting of potassium dichromate. Thus, the present study proves that the pods dye extract of P.jiringa can be used as potential natural dye source and creates awareness on the effective usage of plant wastes in the related industries. Keywords: Pithecellobium jiringa, mordanting technique, colour fastness, K/S ratio