A long jump towards the concept of non-aqueous textile processing is only a single solution to save our planet from the life hazards which is expected to come in the upcoming future. This is a critical time to think over it. Have we ever raised a single step towards this?
The environmental pollution problems have driven impetus in developing the novel concepts in wet processing using supercritical fluid .This novel concept is used for dyeing of synthetic fibers and natural fibres, since, some supercritical fluids are inexpensive, non-toxic, environmentally friendly, chemically inert under many conditions and easily available that can be utilized in textile wet processing at supercritical stage. In SC dyeing process, there is no salt and auxiliaries are required hence, the cost of the effluent treatment will be drastically reduced. The supercritical is non-aqueous process hence it is environmentally friendly. The review of the fundamental properties, the procedure of dyeing and scope of supercritical fluids in textile wet processing is discussed in this paper.
One of the supercritical fluids, which can be used, is carbon dioxide (CO2). Supercritical CO2 is a clean and versatile solvent and a promising alternative to noxious organic solvents and chlorofluorocarbons. It has attracted particular attention as a supercritical fluid in the synthesis as well as processing areas. Color fastness of fibers dyed in supercritical CO2 is similar to fibers dyed in water. Due to the low viscosity of SC-CO2, dissolved dyes readily penetrate into pores and capillaries of fibers more easily as compared to others SCFs. The diffusion coefficient of dye molecules in SC-CO2 is greater than those of liquids and other SCFs which allow faster mass transport and therefore, significant higher dyeing rates which resulting in a short dyeing time.
The authors are associated with the Department of Textile Chemistry, D.K.T.E. Society's Textile & Engineering Institute, Ichalkaranji, Dist-Kolhapur (M.S.)