Press belts and shoe press device using the belts

Abstract

A press belt employed for pressurizing a zonal material, endlessly formed by an elastic material with the thickness progressively reduced from a central pressurizing portion toward end pressurizing portions. A shoe press comprising at least the aforementioned press belt, a pressure shoe applying pressure to the aforementioned press belt and pressure regulation means regulating the pressure of the pressure shoe. Thus, the pressure can be uniformly applied to a zonal material to be pressurized.

1 . A press belt employed for pressurizing a zonal material, endlessly formed by an elastic material with the thickness progressively reduced from a central pressurizing portion toward end pressurizing portions.  
     
     
         2 . The press belt according to  claim 1 , wherein the thickness is progressively reduced from said central pressurizing portion toward said end pressurizing portions by at least one type of technique selected from a group of a crown curve technique, a linear technique, a stepped technique and a trapezoidal technique.  
     
     
         3 . The press belt according to  claim 1 , including a cylindrical endless reinforcing base, a first elastic layer located on the outer peripheral surface of said reinforcing base and a second elastic layer located on the inner peripheral surface of said reinforcing base, wherein the thickness of said first elastic layer is progressively reduced from said central pressurizing portion toward said end pressurizing portions.  
     
     
         4 . The press belt according to  claim 1 , including a cylindrical endless reinforcing base, a first elastic layer located on the outer peripheral surface of said reinforcing base and a second elastic layer located on the inner peripheral surface of said reinforcing base, wherein the thickness of said second elastic layer is progressively reduced from said central pressurizing portion toward said end pressurizing portions.  
     
     
         5 . The press belt according to  claim 1 , wherein the difference between the thickness of said central pressurizing portion and the thickness of said end pressurizing portions is 2 to 30% of the thickness of said central pressurizing portion.  
     
     
         6 . The press belt according to  claim 1 , wherein said press belt is a papermaking press belt.  
     
     
         7 . The press belt according to  claim 1 , wherein said press belt is a shoe press belt.  
     
     
         8 . A shoe press comprising at least the press belt according to  claim 1 , a pressure shoe applying pressure to said press belt and pressure regulation means regulating the pressure of said pressure shoe.