Natural colourants are present in a large variety of plant sources - root, leaf, bark, flower berry, shoot, nut, seed, and fruit. The tannins in Arecanut were being made use of, for dyeing rope and tanning leather. Tannins are obtained as a by-product from the processes preparing immature betel nuts for masticatory purpose. This study is carried out with an objective to dye woollen skeins with Arecanut and assess the colourfastness to washing, sunlight, rubbing and perspiration. Known quantity of natural dyestuff i.e. Arecanut was soaked in water with MLR 1:40 overnight and the same was boiled for 30 min., 45 min. and 60 min. The pH was recorded after dye extraction (aqueous media) and the pH was changed to acidic (pH-4) by adding acetic acid for baths. Finally the optical density was measured using ELICO-SL 171 mini spectro - photometer. The wool skein was dyed in respective medias and their optical density was recorded. Percent dye absorption was calculated for all medias. In general mordanted samples showed better fastness than control, since the mordant plays a vital role in breaking the surface tension of the fibre, there by assign the dye molecule to penetrate into the fibre core. The colourfastness to dry crocking was excellent compared to wet. This may be because of the breakage of dye metal complexes into simple particles during wet rubbing or the physical adherence of excess dye particles on the substrate after saturation was released from the fabric in wet conditions, thus staining material. Alkaline perspiration showed superior colourfastness than acidic, which may be due to the stable electronic configuration of wool sample in alkaline condition. In general wool sample post mordanted with 10 per cent potash alum attained maximum dye absorption and better colourfastness properties.
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