Abstract: 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.

Abstract: The invention refers to a method of obtaining a pore-sealed surface having a desired finished structure on a lacquered sheet or web material, preferably a lacquered slab or board of a material containing wood fibres (lignocellulose) such as board or particle board material. According to the invention the slab or board is coated with a wet or powdery, clear or pigmented lacquer material. The slab or board so coated is dried and/or cured and the slab or board thereafter subjected to a compression operation under high mechanical pressure during a short time so that flowing of the lacquer material and/or sheet material takes place and a surface structure have good evenness and tightness is obtained. The invention also comprises a slab or board of finished structure manufactured according to the invention.

Abstract: A method of compressing at least one flat wooden element having knots therein to permanently increase the hardness of the wooden element. The method includes the steps of inserting an elastic material layer between a pair of spaced apart press plates which are moveable with respect to each other, the elastic material layer being softer than the wooden element. The wooden element is then interposed between the elastic material and one of the press plates, and the pair of press plates displaced toward each to a predetermined spacing thereby compressing the entire surface of the wooden element and elastic material layer, the thickness of the elastic material layer in the compressed state being at least one-half the thickness of the compressed wooden element. Portions of the knots in the wooden element are forced out of the element and into the elastic material layer without being broken to shivers by the pressure exerted thereon.