Machine for producing a fibrous web

Abstract

A gap former for forming a fibrous web from a fibrous suspension supplied via a headbox, having a top fabric ( 3, 28 ) and a carrier or bottom fabric ( 2, 27 ), is defined by the fact that the carrier fabric ( 2, 27 ) has a greater thickness than the top fabric ( 3, 28 ).

1 . A gap former for forming a fibrous web from a fibrous suspension supplied via a headbox, comprising a top fabric and a carrier or bottom fabric, wherein the carrier fabric has a greater thickness than the top fabric.  
   
   
       2 . The gap former of  claim 1 , wherein the top fabric has a thickness of 0.63 mm or less.  
   
   
       3 . The gap former of  claim 2 , wherein the top fabric has a void volume of 400 cm 3 /m 2  or less.  
   
   
       4 . The gap former of  claim 1 , wherein the carrier fabric has a thickness of 0.77 mm or less.  
   
   
       5 . The gap former of  claim 4 , wherein the carrier fabric has a void volume of 400 cm 3 /m 2  or less.  
   
   
       6 . The gap former of  claim 4 , wherein the carrier fabric has an open area of 32% or more.  
   
   
       7 . The gap former of  claim 4 , wherein the carrier fabric has an air permeability of between 360 and 400 cfm.  
   
   
       8 . The gap former of  claim 1 , wherein the number of empty spaces within at least on of the carrier fabric and the top fabric on a side facing the fibrous web is less than or equal to the number of empty spaces on a side facing away from the fibrous web.  
   
   
       9 . The gap former  claim 1 , wherein adjustable and movable foils are set against at least one of the top fabric and the bottom or carrier fabric.  
   
   
       10 . A process for producing a fibrous web, in particular a paper web, which is suitable for gravure printing, having at least one of a top fabric and a carrier fabric of  claim 1 , wherein the fibrous web is produced at a speed of more than 1550 m/min.