Method and device for dyeing a textile substrate

Abstract

A method for dyeing a textile substrate, in particular for dyeing a textile substrate with reactive dyes, is described in which the textile substrate is brought in contact with a dyeing liquor containing at least one dye and after a predetermined dyeing time has elapsed, the dyed textile substrate is rinsed. The at least one dye which has not been fixed by the textile substrate and is present in the dyeing liquor is destroyed by a chemical and/or physical treatment to such an extent that the dyeing liquor is largely colourless hereafter, whereby the textile substrate being rinsed with the largely decolourised liquor. A device for carrying out the method comprises a vessel for receiving the textile substrate to be dyed and a circulation system for the dyeing liquor, where a reactor through which the dyeing liquor flows is assigned to the vessel and/or the circulation system and where inside the reactor the chemical and/or the physical treatment of the liquor to be decolourised is carried out.

1 . A method for dyeing a textile substrate, in particular for dyeing a textile substrate with reactive dyes, in which the textile substrate is brought in contact with a dyeing liquor containing at least one dye and after a predetermined dyeing time has elapsed, the dyed textile substrate is rinsed, wherein the at least one dye which has not been fixed by the textile substrate and is present in the dyeing liquor is destroyed by a chemical and/or physical treatment to such an extent that the dyeing liquor is largely colourless hereafter and that the textile substrate is rinsed with the largely decolourised liquor. 
   
   
       2 . The method according to  claim 1 , wherein after a predetermined dyeing time has elapsed, the textile substrate is removed from the dyeing liquor and is transferred to an apparatus for rinsing, wherein the rinsing liquor laden with non-fixed dye is subjected to chemical and/or physical treatment. 
   
   
       3 . The method according to  claim 1 , wherein the at least one dye not fixed by the textile substrate and present in the dyeing liquor or the rinsing liquor is destroyed by a chemical treatment. 
   
   
       4 . The method according to  claim 1 , wherein an oxidative treatment is carried out as the chemical treatment. 
   
   
       5 . The method according to  claim 4 , wherein a treatment with ozone is carried out as the oxidative treatment. 
   
   
       6 . The method according to  claim 1 , wherein the dyeing liquor is separated from the dyed textile substrate and the chemical and/or physical treatment takes place thereafter. 
   
   
       7 . The method according to  claim 6 , wherein the textile substrate is rinsed exclusively with the decolourised liquor. 
   
   
       8 . The method according to  claim 7 , wherein the textile substrate is rinsed with the decolourised dyeing liquor in a first step, that in a second step the rinsing liquor laden with non-fixed dye is separated thereafter, that in a third step the non-fixed dye located in the rinsing liquor is destroyed to such an extent that the rinsing liquor is largely colourless and that in a fourth step the textile substrate is rinsed with the largely colourless rinsing liquor. 
   
   
       9 . The method according to  claim 8 , wherein the first to the fourth step is repeated multiple times, in particular twice to fifteen times. 
   
   
       10 . The method according to  claim 1 , wherein treatment with ozone is carried out as the chemical treatment of the dyeing liquor and/or the rinsing liquor and that the treatment with ozone is carried out in a reactor allocated to the respective dyeing apparatus, through which the dyeing liquor and/or the rinsing liquor flows continuously. 
   
   
       11 . The method according to  claim 10 , wherein a redox potential measurement, an ozone measurement and/or a pH measurement of the ozone-treated liquor is made at the outlet of the reactor. 
   
   
       12 . The method according to  claim 11 , wherein the quantity of ozone fed into the reactor is controlled depending on the measured redox potential, the measured ozone concentration and/or the measured pH value. 
   
   
       13 . The method according to  claim 1 , wherein a fabric is dyed as the textile substrate. 
   
   
       14 . A device for carrying out the method according to  claim 1 , comprising a vessel for receiving the textile substrate to be dyed and a circulation system for the dyeing liquor, wherein a reactor ( 6 ) through which the dyeing liquor flows is assigned to the vessel ( 12 ) and/or to the circulation system ( 16 ) and that in the reactor ( 6 ) the chemical and/or physical treatment of the liquor to be decolourised is carried out. 
   
   
       15 . The device according to  claim 14 , wherein the vessel ( 12 ) for receiving the textile substrate to be dyed forms the reactor for carrying out the chemical and/or physical treatment. 
   
   
       16 . The device according to  claim 14 , wherein a first piping system ( 19 ) for the dyeing liquor is located on the bottom region ( 15 ) of the vessel ( 12 ), which connects the reactor ( 6 ) via a first valve ( 20 ) and via a liquor pump ( 4 ) to the bottom region ( 15 ) of the vessel ( 12 ) and that the reactor ( 6 ) is connected by means of a second piping system ( 21 ) and a second valve ( 22 ) to the vessel ( 12 ) for supplying the largely colourless dyeing liquor after the treatment. 
   
   
       17 . The device according to  claim 16 , wherein a heat exchanger ( 18 ) is assigned to the second piping system ( 21 ). 
   
   
       18 . The device according to  claim 16 , wherein at least one sensor ( 7 ) for detecting the redox potential, the ozone concentration and/or the pH-value is assigned to the second piping system ( 21 ), wherein the at least one sensor ( 7 ) is located before the second valve ( 22 ) when viewed in the direction of flow of the liquor. 
   
   
       19 . The device according to  claim 14 , wherein a device ( 1 ,  2 ,  3 ) for generating ozone is assigned to the reactor ( 6 ). 
   
   
       20 . The device according to  claim 19 , wherein a third piping system ( 23 ) is allocated to the reactor ( 6 ), which piping system connects the air space in the reactor ( 6 ) to an exhaust air fan ( 9 ) via a residual ozone annihilator ( 8 ) and a third valve. 
   
   
       21 . The device according to  claim 19 , wherein the ozone generator ( 1 ,  2 ,  3 ) is connected to a source for oxygen-enriched air. 
   
   
       22 . The device according to  claim 14 , wherein the vessel ( 12 ) for receiving the textile substrate ( 13 ) to be dyed comprises a storage system assigned to the bottom region ( 15 ), that a deflecting device ( 14 ) for the web strand ( 13 ) is provided above the vessel ( 12 ), wherein the deflecting device ( 14 ) for the web strand comprises a driven mandrel and/or a nozzle channel. 
   
   
       23 . The device according to  claim 14 , wherein the vessel has a dye beam for receiving a web strand. 
   
   
       24 . The device according to  claim 14 , wherein the vessel has at least one holder for receiving at least one bobbin, in particular at least one cross-wound bobbin. 
   
   
       25 . The device according to  claim 14 , wherein the liquor circulation system ( 16 ) is provided with a liquor circulating pump ( 17 ), a heat exchanger ( 18 ), a lint catcher and/or a colour trough.