Process for dyeing of textile materials using supercritical fluid

A process for dyeing a textile material 108 using supercritical fluid 112, comprising:

• mixing at least one dye material 102 in at least one solvent 104 to obtain at least one dye solution 106, wherein the at least one solvent 104 comprises at least one of water, acetone, ethanol, or hexane;
• pre-treating a surface of said textile material 108 with a quantity of said at least one dye solution 106 to obtain a dye coated textile material 110 with a controlled quantity of dye molecules per unit textile surface to achieve desirable reproducibility of final color shade and desired color intensity, wherein a thin uniform layer of said at least one dye material 102 on said surface of said textile material 108 enables an effective contact of said at least one dye material 102 with said supercritical fluid 112 acting also as solvent for said at least one dye material 102;
• treating said dye coated textile material 110 using a drying process to control a level of at least one of (i) moisture and/or (ii) solvent content of said dye coated textile material 110;
• placing said dye coated textile material 110 in a supercritical fluid dyeing vessel;
• characterized in that the process further includes,
• adding said supercritical fluid 112 into said supercritical fluid dyeing vessel at a controlled temperature and pressure, wherein said controlled temperature ranges from 35° C. to 150° C. and said controlled pressure ranges from 100 Bar to 700 Bar, wherein said controlled temperature and pressure are determined based on the nature and solubility of dye molecule in said supercritical fluid 112, a type of said textile material 108 and their interaction with said supercritical fluid 112 being used as solvent for said dyeing process;
• solubilizing said thin uniform layer of said at least one dye material 102 on said surface of said textile material 108 using said supercritical fluid 112 as a solvent to obtain a higher solubility and concentration of dye molecules in said supercritical fluid 112 on said surface of said textile material 108 due to a presence of said thin uniform layer of said at least one dye material 102 on surface of said dye coated textile material 110 and further diffusing said solubilized at least one dye material 102 inside the surface, pores and capillaries of said textile material 108;
• and
• depressurizing said supercritical fluid dyeing vessel below supercritical condition to precipitate and entrap said at least one dye material 102 in the said textile material 108.