Powder mix and a method for producing a building panel

Abstract

A powder mix layer for a building panel and a method for producing a building panel with a decorative surface produced from a powder mix layer with a controlled loss on cure. A method of producing a building panel including the steps of applying a powder mix layer on a substrate, and applying heat and pressure to the powder mix layer and curing the powder mix layer having a loss on cure in the range of about 2 to about 7 wt-%, and thereby obtaining a layer formed by the powder mix layer.

1 - 20 . (canceled) 
     
     
         21 . A method of producing a building panel comprising the steps of:
 applying a powder mix layer on a substrate, the powder mix layer comprising a fiber and a binder; and   applying heat and pressure to the powder mix layer having a free moisture content in the range of about 0.6 to about 6.1 wt-%, and thereby obtaining a layer of the building panel formed by the powder mix layer.   
     
     
         22 . The method according to  claim 21 , wherein the powder mix layer comprises wood fibres and a binder. 
     
     
         23 . The method according to  claim 21 , comprising the further step of applying a stabilization fluid on the powder mix layer. 
     
     
         24 . The method according to  claim 21 , comprising the further step of drying the powder mix layer. 
     
     
         25 . The method according to  claim 21 , comprising the further step of fixing the powder mix layer to the substrate. 
     
     
         26 . The method according to  claim 21 , further comprising adjusting the free moisture content of the powder mix layer by a step of applying the stabilization fluid, or a step of drying, or a combination thereof such that the powder mix layer obtains the free moisture content in said range. 
     
     
         27 . The method according to  claim 21 , wherein the powder mix layer is applied by scattering. 
     
     
         28 . The method according to  claim 21 , wherein the powder mix layer is applied as a continuous powder mix sheet. 
     
     
         29 . The method according to  claim 21 , wherein the substrate is a core of the building panel. 
     
     
         30 . The method according to  claim 29 , wherein the layer forms a decorative surface layer arranged on the core. 
     
     
         31 . The method according to  claim 21 , wherein the free moisture content of the powder mix layer is in the range of about 1.2 to about 4.9 wt-% for the step of applying heat and pressure to the powder mix layer. 
     
     
         32 . The method according to  claim 24 , wherein the step of drying comprises applying heat with an effect of about 15-25 kW/m and a feeding speed of the substrate in the range of about 1-4 m/min. 
     
     
         33 . The method according to  claim 25 , wherein the step of fixing comprises applying stabilization fluid and drying with an effect of about 15-25 kW/m and a feeding speed of the substrate in the range of about 1-4 m/min. 
     
     
         34 . The method according to  claim 29 , wherein the substrate is a wood-based core. 
     
     
         35 . The method of  claim 21 , the method further comprising determining the free moisture content for the powder mix layer. 
     
     
         36 . The method of  claim 35 , the method further comprising adjusting the free moisture content of the powder mix layer by a step of applying a stabilization fluid, or a step of drying, or a combination thereof, such that the powder mix layer obtains the free moisture content in said range. 
     
     
         37 . The method according to  claim 22 , wherein the substrate is a wood-based core and the substrate is a core of the building panel. 
     
     
         38 . The method of  claim 37 , the method further comprising determining the free moisture content for the powder mix layer. 
     
     
         39 . The method of  claim 38 , the method further comprising adjusting the free moisture content of the powder mix layer by a step of applying the stabilization fluid, or a step of drying, or a combination thereof, such that the powder mix layer obtains the free moisture content in said range. 
     
     
         40 . The method according to  claim 38 , wherein the free moisture content of the powder mix layer is in the range of about 1.9 to about 4.3 wt-% for the step of applying heat and pressure to the powder mix layer. 
     
     
         41 . A method of producing a building panel comprising the steps of:
 applying a powder mix layer on a substrate, the powder mix layer comprising a fiber and a binder;   adjusting a free moisture content of the powder mix layer by a step of applying a stabilization fluid, or a step of drying, or a combination thereof, such that the powder mix layer obtains the free moisture content in a range of about 0.6 to about 6.1 wt-%; and   applying heat and pressure to the powder mix layer having the free moisture content in the range of about 0.6 to about 6.1 wt-%, and thereby obtaining a layer of the building panel formed by the powder mix layer.   
     
     
         42 . A powder mix layer for producing a building panel, wherein the powder mix layer comprises a fiber and a binder and has a free moisture content in the range of about 0.6 to about 6.1 wt-%. 
     
     
         43 . The powder mix as claimed in  claim 42 , wherein the powder mix is a substantially homogenous mix of wood fibres, a binder, and wear resistant particles. 
     
     
         44 . The powder mix as claimed in  claim 43 , wherein the binder is a melamine resin. 
     
     
         45 . The powder mix as claimed in  claim 43 , wherein the wear resistant particles consist essentially of aluminum oxide or of a silica powder.