Method for impregnating a textile material

Abstract

A process for continuously impregnating a textile substrate involving: (a) providing an impregnating compartment through which the textile substrate is passed; (b) providing an impregnating liquor present in the impregnating compartment, the impregnating liquor containing: (i) lye; and (ii) an oxidative bleaching agent; (c) providing a bypass member for redirecting fluid; (d) branching off a portion of the impregnating liquor from the impregnating compartment, thus forming a branched off portion of impregnating liquor; (e) heating the branched off portion of impregnating liquor to form a heated branched off portion of impregnating liquor; (f) providing a filtration unit; (g) filtering the heated branched off portion of impregnating liquor through the filtration unit to form a filtered impregnating liquor; and (h) delivering the filtered impregnating liquor to at least one sensor used for determining the concentration of the impregnating liquor.

1 . A process for the continuous impregnation of textiles, more particularly wet textiles, in an impregnating compartment ( 1 ) containing the impregnating liquor through which the textile is passed, the impregnating liquor containing as impregnating medium a lye, more particularly soda lye, or a lye, more particularly soda lye, and in addition an oxidative bleaching agent, more particularly hydrogen peroxide, part of the impregnating liquor being branched off, more particularly continuously, through a bypass ( 2 ,  2   a ), filtered and delivered to one or more sensors ( 17 ,  21 ) for determining the concentration of the impregnating medium, characterized in that the part of the impregnating liquor which is branched off is heated before filtration.  
     
     
         2 . A process as claimed in  claim 1 , characterized in that the branched-off part of the impregnating liquor is heated before filtration to a temperature of 30 to 60° C. and more particularly to a temperature of about 40° C.:  
     
     
         3 . A process as claimed in any of the preceding claims, characterized by automatic cyclic rinsing ( 29 , 30 , 31 ) of the filtration unit ( 4 , 5 ), more particularly with heated process water.  
     
     
         4 . A process as claimed in any of the preceding claims, characterized in that amperometric and/or potentiometric sensors ( 17 , 21 ) are used to determine the concentration of the impregnating medium and a two-point calibration is used to calculate the concentration.  
     
     
         5 . A process as claimed in any of the preceding claims, characterized in that sample preparation necessary for the hydrogen peroxide sensor ( 17 )—more particularly dilution or pH adjustment ( 9   a , 9   b ) of the branched-off part of the impregnating liquor—is carried out.  
     
     
         6 . A process as claimed in any of the preceding claims, characterized in that the sample is galvanically separated ( 16 , 20 ) from the rest of the impregnating liquor before it is delivered to the sensor ( 17 , 21 ).  
     
     
         7 . A process as claimed in any of the preceding claims, characterized in that, in the event of any interruption in the determination of concentration (analysis), the sensors ( 17 , 21 ) are switched to standby operation ( 35 , 36 ).  
     
     
         8 . A process as claimed in any of the preceding claims, characterized in that the reference system ( 22 ) of the soda lye sensor ( 21 ) is regularly cleaned ( 32 , 33 , 34 ).  
     
     
         9 . A process as claimed in any of the preceding claims, characterized in that the signals of the sensors ( 17 , 21 ) corresponding to the measured concentrations are delivered to a control unit for replenishing the impregnating medium.