Studies of Dyeing of Silk Fabric with Natural Indigo Using Pad-Dry and Pad-Batch Techniques

Abstract

Natural indigo dye was applied on silk fabric by using pad-batch and pad-dry techniques in the present of thiourea dioxide and sodium hydroxide. Alum (AlK(SO4)2), ferrous sulfate (FeSO4), and stannous chloride (SnCl2) were used as mordants. The colour of each dyed fabric was investigated in terms of the L*, a*, b* and K/S values. The effects of different dye concentrations with the use of applying padding techniques in the dyeing process was investigated. The colour fastness to washing, light, rubbing, water, and perspiration of dyed silk fabrics was performed according to the present ISO standard. Silk fabric was dyed by using a natural indigo colourant, applying one with metal mordant and one without giving the silk fabric a blue shade. However, a greenish blue shade was found as a dyeing result by adding a ferrous sulfate mordant. The fastness properties of washing, water, perspiration, and rubbing were very good level. However, a fair rating level was observed using a light fastness dyeing technique.