Extraction from babul (Acacia nilotica) bark and efficacy of natural colour on woollen yarn

The study describes the different mediums for extraction of colour from babul (Acacia nilotica) bark and their efficacy. Aqueous, acidic, alkaline and alcoholic mediums were used. Colorant extraction was higher in slight alkaline medium (0.1% Na₂ CO₃) at 100° C for 60 min compared to other mediums. The dried extracts in different mediums produced different shades of brown and grey on woollen yarn with and without mordant. Colorants extracted in alkaline medium showed higher colour strength (K/S) values than other mediums. The produced shades had very good fastness to light and washing treatments.