A METHOD FOR INCREASING THE PERMEABILITY OF WOOD

摘要

A method for increasing the perme-ability of wood which comprises subjecting wood with a moisture content (based on dry weight) of at least 15 % to microwave radi-ation at a frequency (f) in the range of from about 0.1 to about 24 GHz with a power in-tensity (p) from about 10 W/cm2 to about 100 kW/cm2 for a duration of from about 0.05 to about 600 seconds to cause water in the wood to vaporise resulting in an internal pres-sure in the wood such that the permeability of the wood is increased by partial or com-plete destruction of ray cell tissue, softening and displacement of wood resin, formation of pathways in the radial direction of the wood and/or by creating, on the base of destroyed rays, cavities in the wood, said cavities be-ing primarily in radial-longitudinal planes of the wood, and wherein the overall integrity of the wood is substantially maintained. A wood-based material may be formed having a permeability which is at least 5 times that of the untreated wood.