Sulpher Black Dyeing of Raw White Stretch Denim Fabrics Using Continuous Mercerizing Machine

Md. Kaiser Haider, Zakaria Ahmed, F.A. Dilruba, Shamina Jafrin, Musfiqur Rahman

A new method of dyeing raw white stretch denim fabrics using continuous mercerizing range was developed. An un-pretreated raw white denim fabric of 8.25 oz/yd2 weight having construction of (10s OE+12s Ring Slub+12s OE) ×150L70D/75×60 was selected as experimental fabric. The fabric was firstly mercerized at 20 Baume caustic soda concentrations and then dyed in 4 dip 4 nip sulpher black dye bath of 2.5 g/l concentration with a redox value/ milivolt value of –(700-710) followed by 2 step washing, neutralization and steam drying continuously. Color fastness to wash of the dyed fabric was found grade 4.5 and cross-staining grade to acetate, cotton, nylon, polyester, acrylic and wool was 4.5.Dry rubbing and wet rubbing grade in both warp and weft direction was found 3.4 and 2.3 respectively. Tensile strength in warp and weft was found 84.7 kg and 44.2 kg respectively. Length and width shrinkage was 3% and 14.5% respectively with a skew displacement of 2%.The method is a novel approach, rapid, innovative and time saving as well.