Indigo and ring dyeing process using high concentration of caustic and material produced thereof

Abstract

A method of ring dyeing a yarn comprises a series of steps, including providing a yarn chosen from the group consisting of open-end yarns and ring yarns. The yarn is immersed for between 7 to 40 seconds in a caustic bath having a caustic concentration of 50 to 175 g/l. The yarn is skyed after removal from the caustic bath. The yarn is rinsed in water after skying. The yarn is chosen from one of open-end yarn and ring yarn and is dyed in only one sulfur dye box when the yarn is open-end yarn and ring yarn or is dyed at least one indigo dye box when the yarn is open-end yarn. The yarn is washed in water after the dyeing step and thereafter the dyed yarn is dried.

1 . A method of ring dyeing a yarn, comprising the steps of:
 providing a yarn chosen from the group consisting of open-end yarns and ring yarns;   immersing the yarn for between 7 to 40 seconds in a caustic bath having a caustic concentration of 50 to 175 g/l;   skying the yarn after removal from the caustic bath   rinsing the yarn in water after skying;   dyeing yarn chosen from one of open-end yarn and ring yarn in only one sulfur dye box or dyeing open-end yarn at least one indigo dye box;   washing the yarn in water after the dyeing step; and   drying the dyed yarn.   
     
     
         2 . The method as defined in  claim 1 , wherein the caustic bath has temperature of up to 80° C. 
     
     
         3 . The method as defined in  claim 2 , wherein the caustic bath has a temperature from 15 to 50° C. 
     
     
         4 . The method as defined in  claim 1 , wherein the step of washing the yarn is accomplished with continuous water flow at room temperature. 
     
     
         5 . The method as defined in  claim 1 , further comprising the step of dyeing the yarns after the washing step. 
     
     
         6 . The method as defined in  claim 1 , including the step of maintaining the pH of the water less than the pH in the dye box. 
     
     
         7 . The method as defined in  claim 1 , including the step of rinsing the yarn for 6 to 40 seconds. 
     
     
         8 . A method of ring dyeing a yarn, comprising the steps of:
 providing an open-end yarn or a ring yarn;   immersing the yarn in a caustic bath having a caustic concentration of 50 to 175 g/l for between 7 to 40 seconds;   rinsing the yarn in water at room temperature;   immersing the open-end yarn or the ring yarn in sulfur dye in only one sulfur dye box;   washing the yarn immediately after dyeing in water at room temperature; and   drying the dyed yarn.   
     
     
         9 . The method as defined in  claim 8 , wherein the step of rinsing the yarn is accomplished with continuous water flow at room temperature. 
     
     
         10 . The method as defined in  claim 8 , wherein the caustic bath has a temperature of 15 to 50° C. 
     
     
         11 . The method as defined in  claim 10 , including the step of dyeing the yarn after drying. 
     
     
         12 . The method as defined in  claim 8 , wherein pH range of the sulfur dye is 10.0 to 13.7. 
     
     
         13 . The method as defined in  claim 8 , including the step of eliminating wetting agents from the sulfur dye. 
     
     
         14 . The method as defined in  claim 8 , including the step of maintaining the pH in the rinse water at between 10.5 and 11. 
     
     
         15 . A method of ring dyeing a yarn, comprising the steps of:
 providing an open-end yarn;   immersing the yarn in a caustic bath having a caustic concentration of 50 to 175 g/l for between 7 to 40 seconds;   rinsing the yarn in water at room temperature;   immersing the open-end yarn in at least one indigo dye bath;   skying the open-end yarn after indigo dyeing; and   washing the open-end yarn after skying in water at room temperature.   
     
     
         16 . The method as defined in  claim 15 , wherein the caustic bath has a temperature of from 15 to 50° C. 
     
     
         17 . The method as defined in  claim 16 , including the step of maintaining the pH of the indigo dye at 11.4 to 11.6. 
     
     
         18 . The method as defined in  claim 15 , including the step of maintaining the pH in the rinse water at less than the pH of the dye bath. 
     
     
         19 . The method as defined in  claim 15 , wherein the step of washing the yarn is accomplished with continuous water flow at room temperature. 
     
     
         20 . The method as defined in  claim 15 , further comprising the step of skying the open-end yarns immediately after the step of indigo dyeing. 
     
     
         21 . The method as defined in  claim 15 , including the step of dyeing the yarn after drying. 
     
     
         22 . Method of preparing a yarn for ring dyeing, comprising the steps of:
 providing a yarn that is one of an open-end yarn and a ring yarn;   immersing the yarn in a caustic bath having a caustic concentration of 50 to 175 g/l and a temperature of no more than 80° C. if the yarn is an open-end yarn intended for indigo dyeing and an open-end yarn or a ring yarn intended for sulfur dyeing, the yarn being immersed for between 7 to 40 seconds;   
       rinsing the yarn in water at room temperature after removal from the caustic bath; and 
       forwarding the yarn for dyeing. 
     
     
         23 . The method of  claim 1 , including the step of immersing the yarn in the dye box for 7 to 10 seconds. 
     
     
         24 . The method of  claim 1 , including the step of skying the yarn for 1 to 18 seconds when sulfur dye is to be applied. 
     
     
         25 . The method of  claim 7 , including the step of skying the yarn for 1 to 14 seconds if sulfur dye is applied and skying the yarn for 30 to 140 second if indigo dye is applied. 
     
     
         26 . The method of  claim 1 , including the step of applying the sulfur dye at a MV between −480 to −750 mv. 
     
     
         27 . The method of  claim 26 , including the step of maintaining the MV between −550 to −700. 
     
     
         28 . A garment manufactured from a fabric having yarns dyed as defined in  claim 1 .