Method and system for producing a wet-laid non-woven fabric web

Abstract

A method for producing a wet-laid non-woven fabric web includes: providing a first suspension with natural pulp fibers in a first tank, providing a second suspension with regenerated cellulose fibers in a second tank, combining the first suspension and the second suspension to create a mixture, feeding the mixture to a headbox and dewatering the mixture in the forming section of a machine for producing the wet-laid non-woven fabric web. The second suspension with the regenerated cellulose fibers is conveyed by a volumetric pump, in particular by an eccentric screw pump, from the second tank into the volume flow of the first suspension. Wherein over the entire conveying path between the second tank and the headbox, the second suspension is not conducted through any mixing chest having a stirrer. Furthermore, a corresponding system for carrying out the method is taught.

1 . A method for producing a wet-laid nonwoven web, which comprises the following steps of:
 providing a first suspension containing natural pulp fibers in a first tank;   providing a second suspension containing regenerated cellulose fibers in a second tank;   combining the first suspension and the second suspension to generate a mixture by conveying the second suspension containing the regenerated cellulose fibers from the second tank by means of a volumetric pump into a volume stream of the first suspension, with the second suspension not being passed through any mixing chest having a stirring mechanism over an entire conveying path between the second tank and a headbox;   supplying the mixture to the headbox; and   dewatering the mixture in a forming section of a machine for producing the wet-laid nonwoven web.   
     
     
         2 . The method according to  claim 1 , which further comprises conveying the first suspension containing the natural pulp fibers from the first tank by means of a further volumetric pump into a volume stream of the second suspension, with the first suspension not being passed through any said mixing chest containing the stirring mechanism over an entire conveying path between the first tank and the headbox. 
     
     
         3 . The method according to  claim 1 , wherein the first suspension is one of a plurality of first suspensions containing the natural pulp fibers disposed in a plurality of first tanks. 
     
     
         4 . The method according to  claim 3 , which further comprises mixing the plurality of first suspensions with one another in at least one mixing chest containing a stirring mechanism before they are conveyed further into a volume stream of the second suspension. 
     
     
         5 . The method according to  claim 1 , wherein the regenerated cellulose fibers contain viscose and/or lyocell. 
     
     
         6 . The method according to  claim 1 , wherein the wet-laid nonwoven web undergoes waterjet needling in the machine for producing the wet-laid nonwoven web. 
     
     
         7 . The method according to  claim 6 , wherein a production operation is configured such that a completed said wet-laid nonwoven web is dispersible in water. 
     
     
         8 . The method according to  claim 1 , wherein all fibers and any further auxiliaries from which the wet-laid nonwoven web is formed are selected such that the wet-laid nonwoven web is biodegradable. 
     
     
         9 . The method according to  claim 1 , wherein the volumetric pump is an eccentric screw pump. 
     
     
         10 . The method according to  claim 2 , wherein the further volumetric pump is an eccentric screw pump. 
     
     
         11 . The method according to  claim 3 , wherein the natural pulp fibers in the first suspensions differ from one another. 
     
     
         12 . A facility for producing a wet-laid nonwoven web, the facility comprising:
 a first tank for a first suspension containing natural pulp fibers;   a second tank for a second suspension containing regenerated cellulose fibers;   a volumetric pump conveying the second suspension containing the regenerated cellulose fibers from said second tank into a volume stream of the first suspension at a combining point for combining the first suspension and the second suspension to generate a mixture;   a headbox being supplied with the mixture, the facility being free from a mixing chest containing a stirring mechanism over an entire conveying path for the second suspension from said second tank up to said headbox; and   a forming section for dewatering the mixture.   
     
     
         13 . The facility according to  claim 12 , further comprising a waterjet needling apparatus for needling the wet-laid nonwoven web. 
     
     
         14 . The facility according to  claim 12 , wherein said volumetric pump is an eccentric screw pump.