Elastic transfer belt

Abstract

Apparatus and process for guiding a fibrous material web, apparatus includes an elastic transfer belt arranged to transfer fibrous material web between an acceptance region and a delivery region, and a delivery element arranged to deliver fibrous material web to elastic transfer belt. During acceptance of fibrous material web from delivery element, elastic transfer belt is arranged to travel at a same speed as or at only a slightly higher speed than delivery element. An accepting element is arranged to accept fibrous material web from elastic transfer belt. During delivery of fibrous material web to accepting element, transfer belt is arranged to travel with a same speed as or with only a slightly higher speed than accepting element. Transfer belt is driven or slowed to be stretched more during delivery of fibrous material web to accepting element belt than during acceptance of fibrous material web from delivery element.

What is claimed:  
     
         1 . An apparatus for guiding a fibrous material web in machines for at least one of producing and processing the fibrous material web, comprising: 
 an elastic transfer belt arranged to transfer the fibrous material web between an acceptance region and a delivery region;    a delivery element arranged to deliver the fibrous material web to said elastic transfer belt, wherein, during acceptance of the fibrous material web from said delivery element, said elastic transfer belt is arranged to travel at a same speed as or at only a slightly higher speed than said delivery element;    an accepting element arranged to accept the fibrous material web from said elastic transfer belt, wherein, during delivery of the fibrous material web to said accepting element, said transfer belt is arranged to travel with a same speed as or with only a slightly higher speed than said accepting element,    wherein said transfer belt is driven or slowed to be stretched more during delivery of the fibrous material web to said accepting element belt than during acceptance of the fibrous material web from said delivery element.    
     
     
         2 . The apparatus in accordance with    claim 1   , wherein said elastic transfer belt is arranged in at least one of a region of a press section for dewatering and a drying section for drying the fibrous material web.  
     
     
         3 . The apparatus in accordance with    claim 1   , wherein said fibrous material web comprises one of a paper, cardboard, and tissue web.  
     
     
         4 . The apparatus in accordance with    claim 1   , further comprising guide rolls arranged to control speeds of said elastic transfer belt; 
 at least one of said guide rolls being positioned in, or subsequently to, a region of delivery of the fibrous material web by said elastic transfer belt,    at least one other guide roll positioned in, or subsequent to, a region of acceptance of the fibrous material web by said elastic transfer belt,    wherein said at least one guide roll is arranged to rotate faster than said at least one other guide roll.    
     
     
         5 . The apparatus in accordance with    claim 4   , wherein at least one additional roll is positioned in said region of acceptance of the fibrous material web by said elastic transfer belt has about a same speed as said at least one other guide roll.  
     
     
         6 . The apparatus in accordance with    claim 4   , wherein said at least one guide roll is positioned behind, relative to a web travel direction, said region of delivery of the fibrous material web to said elastic transfer belt.  
     
     
         7 . The apparatus in accordance with    claim 1   , wherein a speed of said elastic transfer belt during said acceptance of the fibrous material web by said elastic transfer belt is about 0.2% to 5.0% lower than during said delivery of the fibrous material web to said acceptance element.  
     
     
         8 . The apparatus in accordance with    claim 7   , wherein said speed of said elastic transfer belt during said acceptance of the fibrous material web by said elastic transfer belt is about 0.5% to 4.0% lower than during said delivery of the fibrous material web to said acceptance element.  
     
     
         9 . The apparatus in accordance with    claim 1   , wherein said elastic transfer belt is arranged to travels between a press section and a drying section.  
     
     
         10 . The apparatus in accordance with    claim 9   , wherein the fibrous material web is continuously guided by at least one roll or belt in said press section.  
     
     
         11 . The apparatus in accordance with    claim 1   , wherein said elastic transfer belt is arranged to at least one of accept the fibrous material web without any open draw from said delivery element and deliver the fibrous material web without any open draw to said accepting element.  
     
     
         12 . The apparatus in accordance with    claim 1   , wherein said delivery element comprises one of a roll and a belt.  
     
     
         13 . The apparatus in accordance with    claim 12   , wherein said delivery element comprises a press felt.  
     
     
         14 . The apparatus in accordance with    claim 1   , wherein said accepting element comprises one of a roll and a belt.  
     
     
         15 . The apparatus in accordance with    claim 14   , wherein said accepting element comprises one of a drying cylinder and a suctioned roll.  
     
     
         16 . The apparatus in accordance with    claim 1   , wherein said elastic transfer belt is permeable.  
     
     
         17 . The apparatus in accordance with    claim 16   , further comprising suction devices arranged on sides of said elastic transfer belt opposite to the fibrous material web.  
     
     
         18 . The apparatus in accordance with    claim 1   , wherein said elastic transfer belt has a smooth surface.  
     
     
         19 . The apparatus in accordance with    claim 18   , wherein a guide roll is arranged to guide said elastic transfer belt, and said guide roll is positioned between said delivery of the fibrous material web to said acceptance element and said acceptance of the fibrous material web from said delivery element.  
     
     
         20 . The apparatus in accordance with    claim 19   , wherein said guide roll comprises a suctioned roll.  
     
     
         21 . A process for guiding a fibrous material web in an apparatus for at least one of producing and processing the fibrous material web, the apparatus including an elastic transfer belt, a delivery element and an accepting element, the process comprising: 
 transferring, on the elastic transfer belt, the fibrous material web between an acceptance region and a delivery region;    accepting, on the elastic transfer belt, the fibrous material web from the delivery element, and driving the elastic transfer belt, during the accepting of the fibrous material web from the delivery element, to travel at a same speed as or at only a slightly higher speed than the delivery element;    delivering, by the elastic transfer belt, the fibrous material web to the accepting element, and driving the elastic transfer belt, during the delivering of the fibrous material web to the accepting element, to travel with a same speed as or with only a slightly higher speed than said accepting element; and    stretching the transfer belt more during the delivering of the fibrous material web to the accepting element belt than during the accepting of the fibrous material web from the delivery element.    
     
     
         22 . The process in accordance with    claim 21   , further comprising driving the elastic transfer belt in at least one of a region of a press section for dewatering and a drying section for drying the fibrous material web.  
     
     
         23 . The process in accordance with    claim 21   , wherein said fibrous material web comprises one of a paper, cardboard, and tissue web.  
     
     
         24 . The process in accordance with    claim 21   , wherein the apparatus further includes guide rolls, such that at least one of the guide rolls is positioned in, or subsequently to, a region of delivery of the fibrous material web by the elastic transfer belt, and at least one other guide roll positioned in, or subsequent to, a region of acceptance of the fibrous material web by the elastic transfer belt, and wherein the stretching comprises rotating the at least one guide roll faster than the at least one other guide roll.  
     
     
         25 . The process in accordance with    claim 24   , wherein at least one additional roll is positioned in the region of acceptance of the fibrous material web by the elastic transfer belt, and the process further comprises driving the at least one additional roll at about a same speed as the at least one other guide roll.  
     
     
         26 . The process in accordance with    claim 24   , wherein said at least one guide roll is positioned behind, relative to a web travel direction, the region of delivery of the fibrous material web to said elastic transfer belt.  
     
     
         27 . The process in accordance with    claim 21   , wherein a speed of the elastic transfer belt during the acceptance of the fibrous material web by the elastic transfer belt is about 0.2% to 5.0% lower than during the delivery of the fibrous material web to said acceptance element.  
     
     
         28 . The process in accordance with    claim 27   , wherein the speed of the elastic transfer belt during the acceptance of the fibrous material web by the elastic transfer belt is about 0.5% to 4.0% lower than during the delivery of the fibrous material web to the acceptance element.  
     
     
         29 . The process in accordance with    claim 21   , further comprising accepting the fibrous material web on the elastic transfer belt without any open draw from said delivery element and delivering the fibrous material web from the elastic transfer belt without any open draw to the accepting element.  
     
     
         30 . The process in accordance with    claim 21   , wherein the elastic transfer belt is permeable.  
     
     
         31 . The process in accordance with    claim 30   , further comprising suctioning sides of the elastic transfer belt opposite to the fibrous material web.