Ultrasound-assisted pre-treatment and dyeing of jute fabrics with reactive and basic dyes

Ultrasonic dyeing has been investigated as a means to increase the diffusion of the dye molecules into the fiber for the dyeing of various fibers. However, for scouring, bleaching, and dyeing of jute fabrics, the beneficial effect of sonication was never realized. In this work, we report the effect of sonicated scouring and bleaching of jute fabrics on their physicomechanical properties and the dyeability in the conventional dyeing with reactive and basic dyes. The sonicated scoured and bleached fabric showed higher whiteness index and weight loss but the tensile strength and yellowness index decreased compared to the conventionally scoured and bleached jute fabric. The sonicated scoured fabric showed partial removal of lignin but the conventionally scoured fabric did not show any change in lignin content. It was found that in the case of conventional dyeing, the sonicated scoured and bleached fabric produced higher color strength than the jute fabric scoured and bleached at the same conditions but without sonication. Moreover, we also investigated the effect of ultrasound on the dyeing and color fastness properties of jute fabric dyed with two reactive and two basic dyes. It was found that the sonicated dyeing produced higher color strength compared to the fabrics dyed without sonication. Both conventional and sonicated dyed fabric showed very similar color fastness properties to light, washing, and rubbing indicating no degradation of dyes occurred during sonicated dyeing.