New dyeing technique for enhancing colour strength and fastness properties of cotton fabric dyed with natural dyes

Abstract

Dyeing behaviour of four different natural dyes extracted from the leaves collected in a sustainable manner from respective dye containing plants has been studied on cotton fabric. A novel and ecofriendly mordanting technique has been devised for creating aluminium-tannate complex on cotton matrix. The new mordanting technique not only involves application of a modified sequence of mordanting chemicals but also employs addition of specific salts in water used in the dyeing process. The dyeing of the mordanted fabric has been carried out under acidic and alkaline conditions at different temperatures. The modified dyeing technique shows an overall improvement of 140-300% in colour strength along with the excellent fastness properties, such as washing, rubbing, perspiration and light. The overall results indicate that all the four natural dyes can be effectively and economically used for dyeing on cotton fabric. The entire chain of collection, extraction and dyeing methodology is environmentally and ecologically compatible