Extraction, optimisation and dyeing of silk yarn using natural dye from cosmos sp

The use of natural dye decreased in last few decades due to the discovery of synthetic dye in nineteenth century. Recently, non toxic, environment friendly natural dye started receiving much attention in order to avoid hazardous petrochemical raw materials which involve in synthetic dye production and also its non biodegradable effluent. In this study, extraction of a natural dye from Cosmos sp flower was optimised. Pretreated silk yarn was dyed with aqueous extract of the dye. Dyeing was carried out through pre, meta and post mordanting method with the help of permissible chemical mordants –Alum and Ferrous sulphate. Further, these mordants were able to develop different shades of hue with good fastness property. Standardised dyeing protocol was fixed on the basis of different parameters like time, temperature, pH and material to liquor ratio. Extracted dye was also evaluated to determine the principal compound responsible for dyeing the yarn. Preliminary analysis showed the presence of flavonoid in the dye extract. These results revealed extract of Cosmos sp can be a potent source of natural dye in textile industry.