Inclined-wire former and method of producing a fibrous web

Abstract

An inclined-wire former for producing a fibrous web, in particular a long-fibered paper or wet-laid nonwoven web, includes a wire that runs over a breast roll, subsequently runs inclined at an angle with respect to the horizontal, before it is deflected at a deflection point into a substantially horizontal direction. A headbox in the inclined section of the wire applies a fibrous suspension to the top side of the wire. At least one dewatering element is arranged on the bottom side. The headbox has a front wall which defines, together with the wire, an outlet gap for the at least one fibrous suspension. The front wall of the headbox extends in the wire running direction beyond the deflection point of the wire, such that the outlet gap is arranged above the substantially horizontally extending portion of the wire.

1 . An inclined-wire former for producing a fibrous web from at least one fibrous suspension, the inclined-wire former comprising:
 a wire disposed to run over a breast roll and, subsequently in a wire running direction, to run in an inclined section of said wire that is inclined relative to a horizontal before said wire is deflected at a deflection point into a substantially horizontally extending section of said wire;   at least one headbox disposed at the inclined section of said wire and configured to apply at least one portion of the at least one fibrous suspension to a top side of said wire;   said headbox having a front wall which, together with said wire, defines an outlet gap for the at least one fibrous suspension, said front wall extending in the wire running direction beyond said deflection point of said wire and forming said outlet gap above said substantially horizontally extending section of said wire; and   at least one dewatering element disposed at a bottom side of said wire for dewatering the at least one portion of the at least one fibrous suspension applied to said wire.   
     
     
         2 . The inclined-wire former according to  claim 1 , wherein said at least one dewatering element is arranged on the bottom side of said inclined section of said wire, extends in the wire running direction beyond said deflection point of said wire, and ends below said substantially horizontally extending section of said wire. 
     
     
         3 . The inclined-wire former according to  claim 1 , wherein said front wall of said headbox has, in the region of the deflection point of said wire, a curvature or a bend, which causes a spacing between said front wall and said wire to narrow in the wire running direction. 
     
     
         4 . The inclined-wire former according to  claim 3 , wherein said spacing between said front wall and said wire tapers continuously in the wire running direction. 
     
     
         5 . The inclined-wire former according to  claim 1 , further comprising a fixing suction device underneath said substantially horizontally extending section of said wire, said fixing suction device being usable for determining a position of a water line of the at least one fibrous suspension on said substantially horizontally extending section of said wire. 
     
     
         6 . The inclined-wire former according to  claim 5 , further comprising at least one further dewatering element disposed downstream of said fixing suction device, underneath said substantially horizontally extending section of said wire, and configured to further dewater the fibrous web. 
     
     
         7 . The inclined-wire former according to  claim 6 , wherein said at least one further dewatering element is a suction box. 
     
     
         8 . The inclined-wire former according to  claim 1 , further comprising at least one steam blower box arranged above said substantially horizontally extending section of said wire. 
     
     
         9 . The inclined-wire former according to  claim 1 , further comprising at least one top wire arranged above said substantially horizontally extending section of said wire. 
     
     
         10 . The inclined-wire former according to  claim 1 , wherein said wire has at least one of a low air permeability of less than 410 CFM or a high retention value of more than 100 FSI. 
     
     
         11 . The inclined-wire former according to  claim 1 , further comprising edge limiters disposed to laterally surround said substantially horizontally extending section of said wire, at least in certain portions thereof. 
     
     
         12 . The inclined-wire former according to  claim 1  configured for producing a long-fibered paper web or a wet-laid nonwoven web from the at least one fibrous suspension. 
     
     
         13 . A method, comprising:
 providing the inclined-wire former according to  claim 1 ; and   producing a long-fibered paper web or wet-laid nonwoven web with the inclined-wire former.   
     
     
         14 . The method according to  claim 13 , which comprises forming a web selected from the group consisting of a battery separator paper web, an aramid paper web, and a capacitor paper web. 
     
     
         15 . The method according to  claim 13 , which comprises operating the inclined-wire former to form a water line of the at least one fibrous suspension on the substantially horizontally extending section of the wire. 
     
     
         16 . The method according to  claim 13 , which comprises setting a consistency of the at least one fibrous suspension to less than 0.3%. 
     
     
         17 . The method according to  claim 16 , which comprises setting the consistency of the at least one fibrous suspension to lower than 0.02%. 
     
     
         18 . The method according to  claim 13 , wherein the long-fibered paper or wet-laid nonwoven web has a grammage of less than 20 g/m 2 .