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.

Natural fiber-made apparel dyed with natural dyes is drawing consumer attention because of the possible toxic and health hazards associated with fabric dyed with synthetic dyes. However, many textile products dyed with natural dyes available in the market could pose a health risk because of the use of toxic heavy metals as a dye-complexing agent. In this work, jute fabrics were dyed and multi-functionalized with gallotannin (GT), using ferrous sulfate (FeSO 4 ), calcium chloride (CaCl 2 ), and aluminum chloride (AlCl 3 ) as a non-toxic mordanting agent. The shades produced and other physicochemical properties of the GT-dyed jute fabrics were compared with the jute fabric treated with GT using copper sulfate (CuSO 4 ), a common mordanting agent. It was found that the GT with various mordanting agents produced navy blue and brown shades with tonal changes along with quite good colorfastness to washing. The concentration of GT and mordanting agents, types of mordanting agents, and the treatment pH affected the shade produced and physicochemical properties of the treated fabrics. The surface resistivity was reduced from 235 9 10 10 X/sq for the control to 6.7 9 10 10 X/sq for the AlCl 3 mordanting agent, slightly higher than the surface resistivity exhibited by the CuSO 4 mordant. The fabric treated with GT using FeSO 4 and CaCl 2 mordanting agents showed excellent antioxidant activity, even at the lowest GT dosage applied. Similarly, FeSO 4 and CaCl 2 also showed excellent UV radiation absorption capability. The developed treatment can be used in the textile industry to make cellulosic textiles multifunctional without using any toxic dyes and chemicals.

Scouring is necessary for the loom state jute fabrics in order to make them suitable for dyeing and finishing by improving their wettability by removing non-cellulosic matters from the fibre. Scouring is carried out at the boil with a cocktail of caustic soda, detergent, and wetting agent, and the process is energy-intensive. In this work, bio-scouring of jute fabrics was carried out using four kinds of enzymes, Esperase 4.0T (protease), xylanase, and Alcalase 2.5 L (alkaline protease) in a combination with cellulase. The performance of scouring of jute fabrics scoured with various enzymes was evaluated by measuring their whiteness index, hydrophilicity, wettability, and dyeability, and was compared with jute fabrics scoured by the traditional alkali scouring method. The effect of bio-scouring on the weight loss and tensile strength loss was assessed. Of the enzymes investigated, the combined treatment with 50/50 mixture of Alcalase and cellulase provided the best performance in terms of improvement in whiteness index, hydrophilicity, wettability, and dyeability, but also caused the highest loss in

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