Method for production of wood material articles with low emissions of chemical compounds

Abstract

The invention relates to a method for production of wood material articles with low emissions of chemical compounds. The applied wood is treated with bisulphite before bonding. On using formaldehyde resins in the bonding agent, wood material articles can be produced with the inventive method with extremely low formaldehyde emissions and very bright colours.

1 . Method for the production of a wood material article comprising wood chips or wood fibres glued together, wherein the wood is treated prior to the gluing process in saturated water vapour atmosphere or in saturated water vapour air for a duration of 3-8 minutes with bisulphite at a pressure of 6-12 bar. 
   
   
       2 . Method according to  claim 1 ,
 characterized   in that the wood is treated with bisulphite prior to the manufacturing of the wood chips or wood fibres, for example in a cooker.   
   
   
       3 . Method according to  claim 1 ,
 characterized   in that the wood chips or wood fibres are treated with bisulphite, for example in a refiner.   
   
   
       4 . Method according to any one of the preceding claims,
 characterized   in that the bisulphite is added in an amount of 1 to 30 kg/m 3  wood, preferably in an amount of 3 to 12 kg/m 3  wood.   
   
   
       5 . Method according to  claim 4 ,
 characterized   in that the bisulphite is chosen from sodium bisulphate and ammonium bisulphate.   
   
   
       6 . Method according to  claim 4 ,
 characterized   in that the wood treated with bisulphite is conveyed to wood chips or wood fibres and the wood chips or wood fibres are glued with an aminoplast resin.   
   
   
       7 . Method according to  claim 1 ,
 characterized   in that the wood chips or wood fibres are glued with an aminoplast resin, chosen from the group consisting of urea formaldehyde resin, melamin formaldehyde resin, urea-melamin formaldehyde resin and melamin urea phenol formaldehyde resin.   
   
   
       8 . Wood material article, consisting of wood chips or wood fibres, which are glued together. wherein the wood is prior to the gluing process treated with bisulphate in saturated water-vapour atmosphere or in saturated water-vapour air for a duration of 3 to 8 minutes at a pressure of 6 to 12 bar.