Evaluation of physical properties of Korean Pine (Pinus koraiensis Siebold and Zucc.) lumber heat-treated by superheated steam

In this study, the method for heat treating wood using superheated steam (SHS) was designed and applied. The physical and mechanical properties of Korean Pine (Pinus koraiensis Siebold and Zucc.) lumber heat-treated by SHS at 170°C and 0.4 MPa for 10 hours were compared with those of non-treated and normal heat-treated wood. The amount of adsorbed water and equilibrium moisture content of the SHS treated wood were lower than non-treated wood. On the other hand the compressive strength parallel to grain and the bending strength of SHS treated wood were higher than those of non-treated wood. The hygroscopicity of SHS treated wood was similar to normal heat treated wood at 220°C. Internal checks that often occur during normal heat treatment were not developed at SHS treatment. Also, SHS treatment are effective in control of internal checks occurrence and resin exudation.