0023-6152

AA00697606

6770281

This study used Taiwan’s domestic timber–Cryptomeria japonica hot pressed at 180°C for 1 h, and dried at 103±2°C with drying set for 12 h to prepare compression–set wood (CSW). As a control group, compressed wood (CW) was prepared using hot pressing at 180°C for 1 h. The basic properties, compression rate, compression–set rate, thickness recovery (Tr), compression–set recovery (Cr), water absorption, volumetric swelling coefficient, anti–swelling efficiency, and stress wave velocity (Vs) were investigated to realize the difference between the physical properties of CW and CSW. The physical properties of CSW compressed from 22, 24, and 27 mm to 18 mm with drying set had better dimensional stability than those of CW. The higher dimensional stability of CSW is related to the elasticity and plasticity of wood. The wood is upgraded from the elastic zone to the critical point of elastic and plastic zones by compression setting to reach a fixed size effect. In other words, the Tr is decreased without damaging the mechanical properties. The correlation coefficient (r^2) of Vs and CSW with Tr below 3% approaches 0.0, and the r^2 of the Tr of 6–8% was higher than 0.7. After the compression–set recovery test, the r^2 of Cr and Vs of CW and CSW was higher than 0.8, representing a higher correlation. This Vs is able to be applicable for evaluating the physical properties of the woods with large dimensional changes in thickness, as this change can be related to the wood porosity. In summary, the CSW has good physical properties, the dimensional instability of CW can be improved, and the Vs can be used for evaluating the physical properties of CW and CSW.