Endless fabric

Abstract

The invention relates to an endless belt, especially made of felt or sieve, for a machine for producing and/or upgrading a Web ( 1, 11, 21 ) of paper, paperboard, tissue or other fibers. The inventive belt has an increased adhesive power in adhesive zones ( 3, 14, 24 ) that extend opposite the marginal zones ( 4, 12 ) of the fiber web ( 1, 11, 21 ).

1 . An endless fabric, in particular a felt ( 2 ) or a screen ( 13 ,  22 ), for a machine for the manufacture and/or converting of a paper web, a card web, a tissue web or another fiber web ( 1 ,  11 ,  21 ), characterized in that the endless fabric ( 2 ,  13 ,  22 ) has increased adhesion in adhesion zones ( 3 ,  14 ,  24 ) extending opposite the edge regions ( 4 ,  12 ) of the fiber web ( 1 ,  11 ,  21 ).  
     
     
         2 . An endless fabric in accordance with  claim 1 , characterized in that it is formed by a compressible, water absorbing and endless pressing felt ( 2 ) for use in pressing sections for the dewatering of paper webs, card webs, tissue webs or other fiber webs ( 1 ).  
     
     
         3 . An endless fabric ( 2 ) in accordance with  claim 2 , characterized in that the adhesion zones ( 3 ) of the pressing felt ( 2 ) each cover an edge region ( 4 ) of the fiber web ( 1 ) with a width between 2-25 cm.  
     
     
         4 . An endless fabric ( 2 ) in accordance with  claim 2 , characterized in that the pressing felt ( 2 ) is coated with a polymer ( 5 ), preferably polyamide, in the adhesion zone ( 3 ) at least on the side contacting the fiber web ( 1 ).  
     
     
         5 . A method for the manufacture of the endless fabric or pressing felt ( 2 ) in accordance with  claim 4 , characterized in that the adhesion zone is treated with a liquid polymer ( 5 ), and treated again, in particular ground and/or imprinted, after the hardening thereof.  
     
     
         6 . An endless fabric in accordance with  claim 2 , characterized in that the pressing felt ( 2 ) has finer mat fibers in the adhesion zone ( 3 ), at least at the surface contacting the fiber web ( 1 ), than between the adhesion zones ( 3 ), whose diameter is preferably smaller than 27 μm and/or has chemically treated mat fibers.  
     
     
         7 . An endless fabric ( 2 ) in accordance with  claim 2 , characterized in that the pressing felt ( 2 ) has a larger number of mat fibers in the adhesion zone ( 3 ), at least at the surface contacting the fiber web ( 1 ), than at the surface between the adhesion zones ( 3 ).  
     
     
         8 . An endless fabric ( 2 ) in accordance with  claim 2 , characterized in that the thickness of the pressing felt ( 2 ) in the adhesion zone ( 3 ) deviates in the loaded state by a maximum of 1 mm, preferably a maximum of 0.5 mm, from the thickness between the adhesion zones ( 3 ).  
     
     
         9 . An endless fabric in accordance with  claim 2 , characterized in that the compressibility of the pressing felt ( 2 ) in the thickness direction and/or the longitudinal extent of the pressing felt ( 2 ) under tension is as constant as possible over the width of the pressing felt ( 2 ).  
     
     
         10 . An endless fabric, in particular a felt ( 2 ) or a screen ( 13 ,  22 ) for a machine for the manufacture and/or converting of a paper web, a card web, a tissue web or another fiber web ( 1 ,  11 ,  21 ), in particular in accordance with  claim 1 , characterized in that it is formed by a compressible, water absorbing and endless pressing felt ( 2 ) for use in pressing sections for the dewatering of paper webs, card webs, tissue webs or other fiber webs ( 1 ); and in that the pressing felt ( 2 ) has an increased permeability for air in adhesion zones ( 3 ) extending opposite the edge regions ( 4 ) of the fiber web ( 1 ).  
     
     
         11 . An endless fabric in accordance with  claim 1 , characterized in that it is formed by a former screen ( 13 ) of a former for the forming of a sheet of a machine for the manufacture of a paper web, of a card web, of a tissue web or of another fiber web ( 11 ), the screen transferring the fiber web ( 11 ) to a succeeding machine unit ( 11 ) and also continuing to guide the edge strips ( 12 ) of the fiber web ( 11 ) cut off prior to the transfer of the fiber web ( 11 ) after the transfer of the fiber web ( 11 ).  
     
     
         12 . An endless fabric ( 13 ) in accordance with  claim 11 , characterized in that the former screen ( 13 ) has a lower permeability in the adhesion zones ( 14 ) than in the main region ( 15 ) therebetween.  
     
     
         13 . An endless fabric ( 13 ) in accordance with  claim 11 , characterized in that the former screen ( 13 ) is impermeable to air in the adhesion zones ( 14 ).  
     
     
         14 . An endless fabric ( 13 ) in accordance with  claim 11 , characterized in that the former screen ( 13 ) is filled with a polymer in the adhesion zone ( 14 ).  
     
     
         15 . An endless fabric ( 13 ) in accordance with  claim 11 , characterized in that the former screen ( 13 ) has a smooth surface in the adhesion zones ( 14 ) on the side facing the fiber web ( 11 ).  
     
     
         16 . A former comprising a former screen ( 13 ) in accordance with  claim 11 , characterized in that a scraper ( 16 ) and/or water nozzles ( 17 ) and/or air nozzles is/are associated with the adhesion zones ( 14 ) of the former screen ( 13 ) after the transfer of the fiber web ( 11 ) for the removal of the edge strips ( 12 ) from the adhesion zones ( 14 ).  
     
     
         17 . A former in accordance with  claim 16 , characterized in that the former is formed by two former screens ( 13 ,  18 ) arranged over one another, between which the fiber web ( 11 ) extends, with preferably only the former screen ( 13 ) which transfers the fiber web ( 11 ) to the next machine unit having adhesion zones ( 14 ).  
     
     
         18 . A former in accordance with  claim 11 , characterized in that the adhesion zones ( 14 ) only cover part of the edge strips ( 12 ), preferably less than 60%, in particular less than 40%, of the width of the edge strip ( 12 ).  
     
     
         19 . An endless fabric in accordance with  claim 1 , characterized in that it is formed by a dryer screen ( 22 ) of a drying section of a machine for the manufacture and/or converting of a paper web, of a card web, of a tissue web, or of another fiber web ( 21 ), the screen guiding the fiber web ( 21 ) and at least partly wrapping around a heated, rotating dryer cylinder ( 23 ), with the fiber web ( 21 ) coming into contact with the dryer cylinder ( 23 ).  
     
     
         20 . An endless fabric ( 22 ) in accordance with  claim 19 , characterized in that the adhesion zones ( 24 ) of the dryer screen ( 22 ) each cover an edge region of the fiber web ( 21 ) with a width from 30 to 100 mm.  
     
     
         21 . An endless fabric ( 2 ) in accordance with  claim 19 , characterized in that the dryer screen ( 22 ) is filled with a polymer in the adhesion zones ( 24 ).  
     
     
         22 . An endless fabric ( 22 ) in accordance with  claim 19 , characterized in that the dryer screen ( 22 ) has a lower air permeability in the adhesion zones ( 24 ) than in the main region ( 25 ) therebetween.  
     
     
         23 . An endless fabric ( 2 ) in accordance with  claim 19 , characterized in that the dryer screen ( 22 ) is impermeable to air in the adhesion zones ( 24 ).  
     
     
         24 . An endless fabric ( 22 ) in accordance with  claim 19 , characterized in that the dryer screen ( 22 ) has a smooth surface in the adhesion zones ( 24 ) on the side facing the fiber web ( 21 ).  
     
     
         25 . Use of the endless fabric or of the dryer screen ( 22 ) made in accordance with  claim 19  in dryer groups of the dryer section in which only one side of the fiber web ( 21 ) comes into contact with heated dryer cylinders ( 23 ).