Wood strand board

Abstract

A method of production of and a mineral bonded wood strand cement (magnesite, gypsum) board which is produced from a mixture of wood strands or similar fiber material, water, a suitable binder like cement, one or both of magnesite and gypsum, and possibly additives, which mixture is cured under pressure to form a board with a practically entirely closed surface. For the boards according to the invention, wood strands are being used that are broader and wider than used until presently in acoustic wood wool cement (magnesite, gypsum) boards.

1 . A wood strand cement board, manufactured from a mixture comprising wood strands or fiber material, a magnesite, gypsum, and water, which mixture is cured to form a board with a practically entirely closed surface, wherein the wood strands are broader and thinner than wood wool fibers used in wood wool cement boards.  
   
   
       2 . A board as described in  claim 1 , wherein the wood strands have a width of 1 to 12 and a thickness of 0.15-1.0 mm.  
   
   
       3 . A board as described in  claim 1 , wherein edges of the strands are pointed.  
   
   
       4 . A board as described in  claim 3 , wherein the edges of the strands are sharp with angles less than 120°.  
   
   
       5 . A method for the production of wood strand cement boards, the method comprising the steps of: 
 a) distributing in moulds a mixture comprising wood strands, water, magnesite or gypsum.    b) stacking the moulds with the mixture to the desired height;    c) pressing the stack of moulds with the mixture, such that the boards acquire a desired density;    d) maintaining the required height through the use of a bottom below the stack and a top on top of the stack, connected by tie rods during the initial curing stage of the magnesite or gypsum.    
   
   
       6 . A method as described in  claim 5 , wherein the wood strands have a width of 1 to 12 mm.  
   
   
       7 . A method as described in  claim 6 , wherein the wood strands have a thickness of 0.15 to 1.0 mm.  
   
   
       8 . A method as described in  claim 5 , wherein wood strands have pointed edges.  
   
   
       9 . A method as described in  claim 8 , wherein the edges of the strands are sharp with angles less than 120°.  
   
   
       10 . A method as described in  claim 5 , wherein the bottom is situated with a counter-profile, and the top is situated with a counter-profile.  
   
   
       11 . A method as described in  claim 5 , wherein the mixture is distributed onto a relief board, which subsequently is pressed to yield a profile without additional use of cement, magnetite or gypsum.  
   
   
       12 . A method as described in  claim 5 , wherein in the distribution step at least part of the wood strands are oriented more in a longitudinal direction than in a transversal direction in relation to a length of the board.  
   
   
       13 . A product from which beams, strips, lath or planks are sawn from relatively thick boards as described in  claim 1 .  
   
   
       14 . A product from which I beam and other profiles are assembled from strips, lath or planks obtained according to  claim 13 .  
   
   
       15 . A board as described in  claim 2 , wherein the wood strands have a width of 3 to 10 mm, and a thickness of 0.15 to 0.3 mm.  
   
   
       16 . A method as described in  claim 6 , wherein the wood strands have a width of 3 to 10 mm.  
   
   
       17 . A method as described in  claim 7 , wherein the wood strands have a thickness of 0.15 to 0.3 mm.