摘要 |
<p>: Low quality, low density woods are densified to form wood products having the characteristics of high quality natural hardwoods. A green solid wood member having a high moisture content is impregnated with anhydrous ammonia to plasticize the wood into a sponge-like form saturated with water and ammonia. This plasticized wood member is placed between press plates of a cyclic press and, while maintaining the temperature of the wood below 100.degree.C, it is subjected to a plurality of low pressure compression cycles each of about 1/2 to 1 minute duration with the wood being compressed to a predetermined thickness of up to 50% less than its original thickness. It is held at the reduced thickness for a short time and released during each cycle, whereby water and ammonia are squeezed out of the wood down to a moisture content of less than about 30%. The damp wood member of reduced thickness thus obtained is then dried to obtain a kiln dried, densified solid wood product. This method may be used to densify wood planks, pre-glued laminates and thin veneers. For veneers, a simpler pressing system and higher temperatures may be used.</p> |