Process and machine for the manufacture of a paper web that is smooth on one side

Abstract

A method to manufacture a fibrous web in the form of a paper web, which is smooth on one side, by a papermaking machine having a forming area, a pressing area and a drying area. The method including picking up the paper web from the forming area by a water absorbent first press felt; guiding the paper web together with the first press felt and a smooth transfer belt through a first press nip. The smooth transfer belt being configured to substantially not absorb any water. The first press nip being a part of the pressing area. The first press felt being configured to be separated and led away from the paper web immediately after the first press nip. The method further including the steps of leading the paper web together with the smooth transfer belt away from the first press nip; and subsequently leading the paper web from the smooth transfer belt by way of a conditioned water absorbent second press felt, the second press felt not passing through the first press nip; and subsequently guiding the paper web together with the second press felt through a second press nip, the second press nip being associated with the drying area.

1 . A method to manufacture a fibrous web in the form of a paper web, which is smooth on one side, by a papermaking machine having a forming area, a pressing area and a drying area, the method comprising the steps of:
 picking up the paper web from the forming area by a water absorbent first press felt;   guiding the paper web together with said first press felt and a smooth transfer belt through a first press nip, said smooth transfer belt being configured to substantially not absorb any water, said first press nip being a part of the pressing area, said first press felt being configured to be separated and led away from the paper web immediately after the first press nip;   leading the paper web together with said smooth transfer belt away from said first press nip;   subsequently leading the paper web from said smooth transfer belt by way of a conditioned water absorbent second press felt, said second press felt not passing through said first press nip; and   subsequently guiding the paper web together with said second press felt through a second press nip, said second press nip being associated with the drying area.   
   
   
       2 . The method of  claim 1 , further comprising the step of immediately separating said first press felt from the paper web after the paper web passes through said first press nip, said first press felt assuming an angle a >0° with said smooth transfer belt and the paper web as said first press felt is led away from the paper web. 
   
   
       3 . The method of  claim 2 , wherein said angle a >10°. 
   
   
       4 . The method of  claim 1 , wherein said first press nip is associated with the press area, said first press nip being formed by a shoe press. 
   
   
       5 . The method of  claim 1 , wherein said first press felt is a top felt, said smooth transfer belt being a lower band relative to the paper web as the paper web travels through said first press nip in said guiding step. 
   
   
       6 . The method of  claim 5 , wherein the paper web is picked up from said smooth transfer belt proximate to a pickup roll by said second press felt, said second press felt wrapping around said pickup roll. 
   
   
       7 . The method of  claim 6 , wherein said second press nip is formed in between a press element and one of a smoothing cylinder and a Yankee cylinder. 
   
   
       8 . The method of  claim 7 , wherein said press element is a suction roll. 
   
   
       9 . The method of  claim 7 , wherein said press element is said pickup roll. 
   
   
       10 . The method of  claim 7 , wherein said press element is a massive roll. 
   
   
       11 . The method of  claim 7 , wherein said press element is a shoe press unit. 
   
   
       12 . The method of  claim 11 , wherein said shoe press unit is a shoe press roll. 
   
   
       13 . The method of  claim 7 , wherein the paper web is passed on to one of said smoothing cylinder and said Yankee cylinder with the smooth side of the paper web facing one of said smoothing cylinder and said Yankee cylinder, the paper web having attained the smooth side from prior contact with said smooth transfer belt. 
   
   
       14 . A machine to manufacture a paper web that is smooth on one side, the machine comprising:
 a forming area;   a press area downstream from said forming area in a direction of the paper web movement;   a drying area downstream from said press area in said direction;   a water absorbent first press felt configured to pick up the paper web from the forming area;   a smooth transfer belt, the paper web being guided together with said first press felt and said smooth transfer belt through a first press nip in said press area, said smooth transfer belt not substantially absorbing any water, said first press felt being immediately separated from the paper web after the paper web goes through said first press nip, said smooth transfer belt being configured to carry the paper web away from said first press nip; and   a conditioned water absorbent second press felt configured to pick up the paper web from said smooth transfer belt, said second press felt not passing through said first press nip, said second press felt traveling with the paper web in said direction through a second press nip, said second press nip being associated with the drying area.   
   
   
       15 . The machine of  claim 14 , wherein said first compression felt assumes an angle a >0° relative to said smooth transfer belt and the paper web after traveling through said first press nip in said direction. 
   
   
       16 . The machine of  claim 15  wherein said angle a >10°. 
   
   
       17 . The machine of  claim 15 , wherein said first press nip is formed by a shoe press. 
   
   
       18 . The machine of  claim 15 , wherein said first press felt is a top felt, said smooth transfer belt being a lower band, the paper web traveling through said first press nip between said top felt and said lower band. 
   
   
       19 . The machine of  claim 15 , further comprising a pickup roll with said second press felt wrapping thereabout, said second press felt being configured to pick up the paper web from the smooth transfer belt in the vicinity of said pickup roll. 
   
   
       20 . The machine of  claim 19 , further comprising:
 a press element; and   one of a smoothing cylinder and a Yankee cylinder, said second press nip being formed between said press element and one of said smoothing cylinder and said Yankee cylinder.   
   
   
       21 . The machine of  claim 20 , wherein said press element is a suction roll. 
   
   
       22 . The machine of  claim 20 , wherein said press element  42  is said pickup roll. 
   
   
       23 . The machine of  claim 20 , wherein said press element is a massive roll. 
   
   
       24 . The machine of  claim 20 , wherein said press element is a shoe press unit 
   
   
       25 . The machine of  claim 24 , wherein said shoe press unit is a shoe press roll. 
   
   
       26 . The machine of  claim 20 , wherein the paper web is passed on to one of said smoothing cylinder and said Yankee cylinder with the paper's smooth side, which it attained from prior contact with said smooth transfer belt, facing one of said smoothing cylinder and said Yankee cylinder.