Optimization of Procedure for Dyeing with Pure Natural Dye Obtained from Turmeric

Preservation and protection of the environment is one of the most talked about subject in today's industrial and social discourses. The latest trend is purely to make natural dye stuffs. The use of harmful metallic mordants in natural dyes can be replaced by natural mordants to make purely natural dye stuffs. India was the source of earliest natural dyestuffs known to man. The History of dyeing is divided by the date 1856, the year in which Sir William Henry Perkin discovered Mauve the first synthetic dye (Comptons Pictured Encyclopedia). Rapid research strides in synthetic chemistry, supported by the industrialization of textile production not only led to the development of synthetic alternatives to popular natural dyes, but also to a number of synthetic dyes in various hues and colours, that gradually pushed the natural dyes into oblivion. However, environmental issues in the production and application of synthetic dyes once again revived consumer's interest in natural dyes during the last decades of the twentieth century (GULRAJANI M L). The present study was aimed to develop 100% natural bright yellow colour for dyeing of wool, without the use of any synthetic stuffs as mordants. The water soluble yellow dye from turmeric rhizomes (Curcumin) is very fugitive in nature. The hue becomes dull with exposure to time and temperature. The conventional aqueous extraction procedure involves a time gap between the extraction of dye and actual dyeing of the substrate. This exposure to time gap makes the dye dull and unappealing. To achieve the best dyeing results, another way of dyeing was tried and tested, “Simultaneous extraction and dyeing” where, dyeing of substrate is carried out in the same water bath along with the extraction of dye from the raw material. A series of experiments were conducted to compare and analyze the results two different procedures of dyeing, by means of calorimetric analysis, and visually, by trained subject experts. Simultaneous extraction and dyeing method was found to yield best hues of yellow dye, as decided by calorimetric tests and visual analysis. The colours are brighter and appealing as the dye is absorbed by the substrate, as soon it is released in water bath. Different variables standardized were; Method of dyeing, concentration of dye material, temperature for extraction, temperature for dyeing, time for extraction and time for dyeing. The final samples were tested for fastness to light and washing as per the standards laid by Bureau of Indian standards.