Vat Dyeing Using Hydroxyacetone as a Reducing Agent

For dying the cotton with vat dyes, first it is required to reduce the dye using reducing agents. The reduction potential of reducing agent has to be matched with the dye for proper dying. Otherwise the problem of over reduction and under reduction may arise and leads to the change in shade. In conventional vat dyeing process, the vat dye is dissolved using sodium hydrosulphite (hydrose), which is a powerful reducing agent followed by solubilising with sodium hydroxide. This process creates very high pollution problem. In this study, an attempt has been made to see the effect of hydroyaceton and its combination with hydrose as reducing agent. Different reducing agents with different reduction potential at different concentration have been used for dying the cotton fabric with vat dye. And the comparisons of different reducing agents and their blend have been observed in terms of dye pick up and fastness property.