| Popis: |
Variation of relative humidity induced dimensional changes in tangential direction of four diffuse porous hard woods; normal and straight grain woods of ISUNOKI (Cercidiphyllum japonicum), KATSURA (Distylium recmosum), TABUNOKI (Persea thunbergii), and EGONOKI (Styrax japonicum). The Investigated range of relative humidity was the range of the moisture content of wood from 8% at surface absorbed water to 30% at fiber saturation point. By static conditioning method with many steps in relative humidity, woods swelled in a desorption process and shrank in an adsorption process at a limited humidity condition. This was provided on the condition that a conditioning process was changed from desorption process and vice versa. At this condition, wood equilibrium moisture content in an adsorption process was a lower than that in a desorption process in spite of increasing relative humidity. And woods shrinkage at a higher relative humidity in an adsorption process was greater than that at a lower relative humidity in a desorption process. |
