Handbook on Natural Dyes for Industrial Applications (with Color Photographs)

Natural dyes comprises of those colourants (dyes and pigments) that are obtained from animal or vegetable matter without chemical processing. They are mainly mordant dyes although some vat, solvent, pigment, and acid types are known. Natural dyes fall into three categories on the basis of their origin; plant/vegetable origin, Insect/ animal origin and mineral origin. Some of the examples of plants used for producing natural dyes are; Al, Alkanet, Balsam, Bougainvillea, Canna, Tulsi, Terminalia Arjuna, etc. India has a very rich tradition of using natural dyes. The art and craft of producing natural dyed textile has been practiced since ages in many villages by traditional expert crafts persons in the country. Natural dyes, when used by themselves have many limitations of fastness and brilliancy of shade. However, when used along with metallic mordants they produce bright and fast colours. The use of metallic mordants is not always eco friendly, but the pollution problems created by metallic mordants are of very low order and can be easily overcome. Therefore, instead of using unsustainable technology for producing colours one can use mild chemistry to achieve almost similar results. There is a growing demand for eco friendly/non toxic colorants, specifically for health sensitive applications such as coloration of food and dyeing of child textile/leather garments. Recently, dyes derived from natural sources for these applications have emerged as an important alternative to potentially harmful synthetic dyes and pose need for suitable effective extraction methodologies. Natural dyes also referred as mordant dyes; do not readily adhere to cotton so mordants are used. Mordants are needed to set the colour when using natural dyes. It is thus a chemical agent which allows a reaction to occur between the dye and fabric. Some of the important natural dyes are blue dyes, red dyes, yellow dyes, etc. Natural dyes can produce special aesthetic qualities, which, combined with the ethical significance of a product that is environmentally friendly, gives added value to textile production as craftwork and as an industry. Some of the fundamentals of the book are history of natural dyes, promotion of natural dyes, sources of natural dyes, constitutional aspects, requisites of a true dye, types of dye, chemical entities responsible for colors, classification based on chemical nature, classification based on colors, basics of natural dyeing, advantages of natural colors/vegetable dyes, natural dyeing principles, nature of material to be dyed, measurements of mordants and dyestuffs, temperature, mordanting the textiles for natural dyeing, standardization of vegetable dyes, quality standards for vegetable dyes, methods of dye extraction etc. This is a single book with Color Photographs which has information related to extraction of dyestuffs from 19 common flowers, weeds, bark or leaves and its application on cotton silk and wool fabrics for textile industry. The book describes the step wise methodology of extraction, mordanting, dyeing with photos of the actual plants part used for extraction of Natural dye. Shade cards have been incorporated so that the full gamut of colors can be visualized from each dyestuff. This is an invaluable resource for entrepreneurs, technocrats, research scholars, etc.