To prevent a poor wooden feeling, a poor durability, a poor weatherability and a harmful chemical substance from developing and improve the water resistance and the moisture resistance of a board by a method wherein the board produced by shaping wooden element pieces in plasma, which is excited through a glow discharge under normal pressures, is plasma-treated.
In a treating tank 5, flat plate type electrodes are installed parallel to each other in the upper and the lower parts inside thereof. The flat plate type electrodes consist of an upper electrode 1 and a lower electrode 2. A solid derivative 3 is placed on the lower electrode 2. A board after shaped or a treating material 4, which is a mat body in a dry type process for shaping a modified wood-based board, is put between the upper electrode 1 and the lower electrode 2 so as to apply a high tension AC electric field to the upper electrode 1 from a high frequency power source 7 under the condition that a gas is circulated between the electrodes in order to develop plasma between the upper electrode 1 and the lower electrode 2. The board after shaped or the treating material 4, which is the mat body in the dry type process for shaping the wood-based board, is subjected to this plasma action.
SAWADA KOJI
ONISHI KENJI
OKUDAIRA YUZO
