Process for dyeing of textile materials using supercritical fluid

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.

Claims

1. 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.

2. The process as claimed in claim 1, wherein said at least one dye material 102 is mixed with additives, and then mixed with said at least one solvent 104 to obtain said at least one dye solution 106, wherein said additives are at least one of dispersing agents, emulsifiers, and surface active agents.

3. The process as claimed in claim 1, wherein said surface of said textile material 108 is pre-treated with more than one dye solution to obtain a multi-color, multi shade coated textile material with desired design patterns as required, wherein said surface of said textile material 108 is pre-treated with said at least one dye solution 106 using an ink jet printing, and wherein said ink jet printing is performed using a single jet printing and/or a multi jet printing.

4. The process as claimed in claim 1, wherein said surface of said textile material 108 is pre-treated with said at least one dye solution using a coating process to obtain a desired thickness and concentration of said at least one dye material 102 on said surface of said textile material 108.

5. The process as claimed in claim 4, wherein said process comprises maintaining said controlled temperature and pressure of said supercritical fluid 112 at a level to have desirable solubility for coated dye molecules in said supercritical fluid 112, to help in swelling of pores and capillaries of said dye coated textile material 110, and to contribute in reducing glass transition temperature of said textile material 108.

6. The process as claimed in claim 5, wherein at least one type of dye molecules penetrates inside said surface, said pores and capillaries of said textile material 108 along with said supercritical fluid 112 which acts as solvent.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The embodiments herein will be better understood from the following detailed description with reference to the drawings, in which:

(2) FIG. 1 is a flow diagram that illustrates a process of dyeing of textile materials using supercritical fluid according to an embodiment herein; and

(3) FIG. 2 is a flow diagram that illustrates a method of dyeing of textile materials using supercritical fluid according to an embodiment herein.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

(4) The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.

(5) As mentioned, there remains a need for an improved process for efficiently dyeing of textile materials using supercritical fluid. The embodiments herein achieve this by providing a process that involves pre-coating of the textile material with one or more dye materials and then exposing the dye coated textile material to the supercritical fluid, under supercritical conditions. The supercritical fluid that diffuses inside the textile material may swell the matrix and may reduce the glass transition temperature of the textile material. This helps in opening the pores and capillary structure of textile material. Simultaneously, the supercritical fluid dissolves the dye molecules present on the surface of the pre-coated textile material and further helps them to penetrate deep inside the textile material resulting in efficient dyeing with good color fastness. Referring now to the drawings, and more particularly to FIGS. 1 through 2, where similar reference characters denote corresponding features consistently throughout the figures, preferred embodiments are shown.

(6) FIG. 1 is a flow diagram that illustrates a process of dyeing of textile materials 108 with supercritical fluid according to an embodiment herein. One or more dye materials 102 are mixed in at least one suitable solvent 104 (e.g. water, acetone, ethanol, hexane etc. or any other solvent depending on the suitability for the dye molecule) along with any additives (e.g. dispersing agents, emulsifiers, surface active agents etc.) (if required) to obtain one or more dye solutions 106. The textile material 108 is then pre-treated with the one or more dye solutions 106 to obtain a dye coated textile material 110. In one embodiment, the textile material 108 is pre-treated with the one or more dye solutions 106 to obtain the dye coated textile material 110 having uniform coating with desired layer thickness and desired concentration of the one or more dye materials 102 on the surface of the textile material 108. Pre-treating the surface of the textile material 108 provides desired concentration of the one or more dye materials 102 (e.g. dye molecules) with specific and uniform intensity of color on the surface of the textile material 108 and reduces wastage of one or more dye materials 102, and improves utilization of the one or more dye materials 102.

(7) In one embodiment, the textile material 108 is pre-treated with the one or more dye solutions 106 using any suitable technique or process that is used for coating or spreading of dye solution on the surface of textile materials with uniform and desired concentration of dye molecules. In an embodiment, the pre-coating the surface of the textile material 108 with the one or more dye solutions 106 may be achieved with an inkjet printing and/or a multi-jet printing or any suitable method to obtain the dye-coated textile material 110 in a single and/or multi-color with desired patterns, shades etc. as required.

(8) In yet another embodiment, the textile material 108 is pre-treated with the one or more dye solutions 106 using ink jet printing or multi-jet printing to obtain the dye-coated textile material 110 with controlled, optimum quantity of dye molecules per unit textile surface to achieve desirable reproducibility of final color shade and desired color intensity. This facilitates the possibility of having multi-colour designs on the textile while dyeing using supercritical fluids. In yet another embodiment, the pre-treatment of the textile material 108 with the one or more dye solutions 106 controls concentration of the one or more dye materials 102 per unit area on the surface of the textile material 108 to obtain a specific and uniform intensity of color on the textile material 108, and also improves efficient utilization of the one or more dye materials 102. In yet another embodiment, the pre-treatment of the textile material 108 with the one or more dye solutions 106 helps in penetration of the one or more of dye materials 102 inside the pores and capillaries of the textile material 108.

(9) The dye-coated textile material 110 is then exposed to the supercritical fluid 112 in a supercritical fluid dyeing vessel. The dye-coated textile material 110 may be subjected to a suitable process like drying etc., before loading the dye-coated textile material 110 into the supercritical fluid dyeing vessel, to control level of residual moisture and/or solvent content of the dye-coated textile material 110. The supercritical fluid 112 (e.g. supercritical carbon dioxide) solubilizes and diffuses the one or more dye materials 102 inside the surface, pores and capillaries of the dye-coated textile material 110 at a controlled temperature and pressure inside the supercritical fluid dyeing vessel. In yet another embodiment, the pre-coating by the one or more dye materials 102 on the surface of the textile material 108 results in a desired thin layer of dye material that helps in effective contact of the one or more dye materials 102 with the supercritical fluid 112. This helps in higher solubility and concentration of dye molecules in supercritical medium, near the surface of the textile material that needs to be dyed. This also avoids inefficiencies that may be possible due to undesirable channeling of dye dissolved supercritical fluid, which result in non-uniformity in dyeing as observed in conventional supercritical fluid based dyeing processes.

(10) The supercritical fluid dyeing vessel is then depressurized to entrap the one or more dye materials 102 that is diffused inside the textile material 108 to obtain a supercritical fluid dyed textile material 114.

(11) FIG. 2 is a flow diagram that illustrates a method of dyeing a textile material 108 under a supercritical condition according to an embodiment herein. At step 202, one or more dye materials 102 is mixed along with additives in at least one suitable solvent 104 to obtain one or more dye solutions 106. At step 204, the textile material 108 is pre-treated with the one or more dye solutions 106 to obtain a dye-coated textile material 110. Then, the dye-coated textile material 110 may be processed by a suitable method to control residual moisture and/or the solvent content of the dye-coated textile material 110. At step 206, the dye-coated textile material 110 is then placed in a supercritical fluid dyeing vessel. At step 208, the dye-coated textile material 110 is exposed to the supercritical fluid, inside the supercritical fluid dyeing vessel at a controlled temperature and pressure which are above the critical temperature and pressure of the supercritical solvent. At step 210, 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. At step 212, the supercritical fluid vessel is then depressurized to entrap the one or more dye materials 102 that is diffused in the textile material 108 to obtain a supercritical fluid dyed textile material 114. In an embodiment, the supercritical fluid 112 inside the supercritical fluid dyeing vessel is maintained at the controlled temperature and pressure for achieving desired solubility for coated dye molecules in the supercritical fluid, for swelling of the pores and capillaries of the textile material 108, and for reducing the glass transition temperature of the textile material 108. These effects also help in efficient diffusion of the dye molecules inside the textile material 108 to achieve efficient dyeing. The supercritical condition is achieved by maintaining the temperature and pressure above the critical temperature and critical pressure of the said fluid.

(12) The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and therefore such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the appended claims.