A method for decolorization of polyester fabrics is provided. The method for decolorization of polyester fabrics includes putting polyester fabrics into an extraction cell. The method for decolorization of polyester fabrics also includes making a supercritical fluid and a co-solvent flow into the extraction cell. The method for decolorization of polyester fabrics further includes adjusting the temperature in the extraction cell to be greater than or equal to the glass transition temperature of the polyester fabrics, so that the supercritical fluid and the co-solvent perform a decolorization reaction on the polyester fabrics. Moreover, the method for decolorization of polyester fabrics includes making the supercritical fluid and the co-solvent flow out of the extraction cell. The method for decolorization of polyester fabrics also includes taking the polyester fabrics out of the extraction cell.

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.

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.

A welded yarn may have a cross section about a plane that is perpendicular to the longitudinal axis of the welded yarn wherein the cross-sectional area is comprised of two or more distinct portions, wherein the degree of welding in each portion is different, which may also result in different fiber volume ratios compared to raw yarn substrates.