Radial compression of sugi wood (Cryptomeria japonica D. Don)

This paper deals with the heat fixation of compressive deformation of sugi wood (Cryptomeria japonica D. Don) which is a typical Japanese coniferous wood with a low density. After wet specimens were compressed in the radial direction to about 50% of their original thickness and dried under restraint, they were subjected to heat treatment by three methods: beneath the surface of molten metal, and in the presence or absence of air. The relationship between the recovery of deformation and the weight loss was expressed by a hyperbolic equation regardless of heating methods. The retentions of the MOE and the MOR of compressed specimens at the perfect fixation were 89% and 81%, respectively. The perfect fixation of deformation was speculated to have resulted from the release of stresses stored in the cell wall polymers by their degradation as well as the reduction of hygroscopicity of the cell wall polymers.