The analysis of dimensional changes due to chemical treatments and water soaking for Hinoki (Chamaecyparis obtusa) wood

To clarify tangential and radial dimensional changes in hinoki (Chamaecyparis obtusa) wood by kinds of treatments and successive water soaking. a vector expression on the tangential-radial nates was proposed and a new measure (ASE') to evaluate the dimensional stability of wood was The ASE' is expressed by 100(1 - V-s/V-u) where V-u is the volumetric swelling coefficient of wood and V-s is that of treated wood calculated on the basis of its oven-dried volume before The results from formaldehyde treated, heat treated and steam treated wood showed large positive values and the ratio of radial swelling to tangential swelling (swelling anisotropy) of these treated decreased with increasing weight percent gain or weight loss. The results from acetylated wood, impregnated with polyethylene glycol and wood treated with a low molecular weight phenolhyde resin showed either small positive or negative ASE' values, and those of wood treated with lene oxide showed large negative values. The swelling anisotropy of treated woods accompanied by wall bulking was larger than that of untreated wood. The swelling anisotropy decreased when the lumen was filled with a hydrophobic resin (WPC-MMA), and increased when the cell lumen was with a hydrophilic resin (WPC-HEMA).