Process for the production of hydraulic binder boards having tapered cut ends

Abstract

A process and a line is for the production of hydraulic binder boards having tapered cut ends, the hydraulic binder being in particular gypsum. The process includes: i) spraying a softening liquid on at least one cut end ( 24 a, 24 b ) of the board ( 24 ); ii) waiting for the softening liquid to penetrate the board ( 24 ); and iii) applying pressure on said at least one cut end ( 24 a, 24 b ) of said hydraulic binder board ( 24 ). According to another aspect, the process includes moving at least one first and one second hydraulic binder boards ( 24 ) on a conveyor; and applying pressure on the cut ends ( 24 a ) of said hydraulic binder boards ( 24 ).

1 . A process for the production of a hydraulic binder board having at least one tapered cut end, comprising the steps of 
 i) spraying a softening liquid on at least one cut end of the board;    ii) waiting for the softening liquid to penetrate the board; and    iii) applying pressure on said at least one cut end of said hydraulic binder board.    
   
   
       2 . A process according to  claim 1 , comprising a subsequent step of drying said pressed at least one cut end of the board.  
   
   
       3 . A process according to  claim 1 , wherein said pressure is applied by a heated press.  
   
   
       4 . A process according to  claim 1 , wherein the softening liquid is selected from the group consisting of water, alcohols, spirits, propylen glycol and their mixtures.  
   
   
       5 . A process for the production of hydraulic binder boards having tapered cut ends, the process comprising: 
 a) moving at least one first hydraulic binder board having first and second cut ends on a conveyor until it reaches a pressing area;    b) moving at least one second hydraulic binder board having first and second cut ends on the conveyor until it reaches said pressing area and its first cut end contacts the second cut end of said at least one first hydraulic binder board;    c) applying pressure on first cut end of said at least one first hydraulic binder board;    d) applying pressure on both second cut end of said at least one first hydraulic binder board and first cut end of said at least one second hydraulic binder board; and    e) applying pressure on second cut end of said at least one second hydraulic binder board.    
   
   
       6 . A process according to  claim 5 , wherein said pressures axe applied simultaneously.  
   
   
       7 . A process according to  claim 5 , wherein said steps a) to e) are applied similarly to third and fourth hydraulic binder boards.  
   
   
       8 . A process according to  claim 5 , wherein said pressures are applied by heated presses.  
   
   
       9 . A process according to  claim 5 , wherein said steps a) to e) are carried out before the boards are dried.  
   
   
       10 . A process according to  claim 5 , wherein said steps a) to e) are carried out after the boards are dried and said steps c) to e) are preceded by the steps of 
 i) spraying a softening liquid on at least the cut ends of the boards; and    ii) waiting for the softening liquid to penetrate the boards.    
   
   
       11 . A process according to  claim 10 , comprising a subsequent step of drying the pressed boards.  
   
   
       12 . A process according to  claim 1 , wherein the hydraulic binder is gypsum.  
   
   
       13 . A production line for hydraulic binder boards having at least one tapered cut end, comprising 
 means for spraying a softening liquid on at least one cut end of the board;    means for applying pressure on said at least one cut end of said board.    
   
   
       14 . A production line according to  claim 13 , further comprising a dryer for drying said pressed at least one cut end of the board.  
   
   
       15 . A production line for hydraulic binder boards, comprising: 
 1) means for moving at least one first hydraulic binder board having first arid second cut ends on a conveyor until it reaches a pressing area;    2) means for moving at least one second hydraulic binder board having first and second cut ends on the conveyor until it reaches said pressing area and its first cut end contacts second cut end of said at least one first hydraulic binder board;    3) means for applying pressure on first cut end of said at least one first hydraulic binder board;    4) means for applying pressure on both second cut end of said at least one first hydraulic binder board and first cut end of said at least one second hydraulic binder board; and    5) means for applying pressure on second cut end of said at least one second hydraulic binder board.    
   
   
       16 . A production line according to  claim 15 , wherein said moving means 1) to 2) similarly move third and fourth hydraulic binder boards and said pressure applying means 3) to 5) similarly apply pressures on said third and fourth hydraulic binder boards.  
   
   
       17 . A production line according to  claim 15 , wherein said means for applying pressure are heated presses.  
   
   
       18 . A production line according to  claim 15 , wherein said pressing area is located before the dryer.  
   
   
       19 . A production line according to  claim 15 , wherein said pressing area is located downstream from the dryer and said production line comprises additional means for spraying a softening liquid on at least the cut ends of the boards, these additional means being located between the dryer and said pressing area or in said pressing area.  
   
   
       20 . A production line according to  claim 19 , further comprising an additional dryer for drying the pressed boards.  
   
   
       21 . A production line according to  claim 13 , wherein the hydraulic binder is gypsum.  
   
   
       22 . A process according to  claim 5 , wherein the hydraulic binder is gypsum.