Dyeing of jute and cotton fabrics using Jackfruit wood extract: Part I — Effects of mordanting and dyeing process variables on colour yield and colour fastness properties

Abstract

Conventionally bleached jute and cotton fabrics have been subjected to pre-mordanting with selective single and double mordants using myrobolan (harda) and other mordants (metallic salts) followed by dyeing with aqueous extract of jackfruit wood and then studied for their mechanical and dyeing properties. It is observed that the application of 10-20% myrobolan followed by 10-20% of Al2(SO4)3 or FeSO4 in sequence have been identified as two most prospective mordanting systems. The study on the effect of dyeing process variables on surface colour strength indicates that the 90 min dyeing time, 70-90°C dyeing temperature, 11.0 pH, 1:30 material-to-liquor ratio, 20-30% mordants concentration, 30-40% dye concentration, and 15 gpl common salt are the optimum values with minor differences among the different fibremordant systems studied. Colour fastness to washing, rubbing and exposure to sunlight, in general, and dyeing-pH sensitivity, in particular, for selective fibre-mordants-dye systems have also been assessed and compared. Dyeing at pH 11.0 for both the double pre-mordanting systems offers overall good colour fastness properties.