Abstract: An embodiment herein provides a process for dyeing of textile materials 108 with supercritical fluid. One or more dye materials 102 along with additives (if required) are mixed with at least one suitable solvent 104 to obtain one or more dye solutions 106. A textile material 108 is pre-treated with the one or more dye solutions 106 to obtain a dye coated textile material 110. The dye-coated textile material 110 is exposed to the supercritical fluid 112 in a supercritical fluid dyeing vessel at controlled pressure and temperature. The supercritical fluid 112 solubilizes and diffuses the one or more dye materials 102 inside the surface, pores and capillaries of the textile material 108. The supercritical fluid vessel is then depressurized below supercritical condition to entrap the one or more dye materials 102 in the textile material 108 to obtain a supercritical fluid dyed textile material 114.

Abstract: An embodiment herein provides a control valve having a hollow piston 104. The hollow piston 104 includes a hollow portion 106. The hollow portion 106 includes at least one opening 108 along the side wall of the hollow piston 104. The fluid from an inlet port 116 flows to an outlet port 118 through the at least one opening 108 within the hollow portion 106 along the side wall of the hollow piston 104, when the hollow piston 104 move upwards and the at least one opening 108 within the hollow portion 106 along the side wall of the hollow piston 104 is positioned above the topmost sealing ring 113. The effective flow rate through the control valve may be controlled depending on (a) the relative positioning of the opening 108 within the hollow portion 106 along the side wall of the hollow piston 104 with respect to the topmost sealing ring 113 and (b) the geometry and size of each of the at least one of opening 108 along the side wall of the hollow piston 104.

Abstract: An embodiment herein provides a process for dyeing of textile materials 108 with supercritical fluid. One or more dye materials 102 along with additives (if required) are mixed with at least one suitable solvent 104 to obtain one or more dye solutions 106. A textile material 108 is pre-treated with the one or more dye solutions 106 to obtain a dye coated textile material 110. The dye-coated textile material 110 is exposed to the supercritical fluid 112 in a supercritical fluid dyeing vessel at controlled pressure and temperature. The supercritical fluid 112 solubilizes and diffuses the one or more dye materials 102 inside the surface, pores and capillaries of the textile material 108. The supercritical fluid vessel is then depressurized below supercritical condition to entrap the one or more dye materials 102 in the textile material 108 to obtain a supercritical fluid dyed textile material 114.