PROCEDE DE TRAITEMENT DU BOIS

• Main Author: J.L. DUNN
• Format: Patent
• Language: French
• Published: 12.04.1974
• Subjects: CHEMICAL OR PHYSICAL TREATMENT OF CORK, CANE, REED, STRAW ORSIMILAR MATERIALS; NAILING OR STAPLING MACHINES IN GENERAL; PERFORMING OPERATIONS; PROCESSES, APPARATUS OR SELECTION OF SUBSTANCES FORIMPREGNATING, STAINING, DYEING, BLEACHING OF WOOD OR SIMILARMATERIALS, OR TREATING OF WOOD OR SIMILAR MATERIALS WITHPERMEANT LIQUIDS, NOT OTHERWISE PROVIDED FOR; TRANSPORTING; WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL

1444102 Treating wood DOW CHEMICAL CO 12 Oct 1973 [13 Oct 1972] 47892/73 Heading D1P A process for treating wood comprises preheating the wood by contact with the vapour of an aliphatic chlorinated solvent at 50‹- 125‹C under superatmospheric pressure, immersing the wood in a solution (preferably boiling) of a wood treatment agent in the same solvent under superatmospheric pressure at about the same temperature (50‹-125‹C) for 0.1-10 hours, draining the excess solution and reducing the pressure at least to atmospheric to vaporize the solvent contained in the wood. The solvent vapour pressure is preferably 1.1-5 atmospheres, and that of the solution up to 15 atmospheres. The wood is preferably seasoned, the solvent methylene chloride and the agent pentachlorophenol e.g. at a 2-10% weight concn. The process may be made continuous by the provision of a plurality of wood treatment vessels arranged to operate in staggered cycles so that the vapours from the boiling solution being used to impregnate wood in one vessel are used to preheat new wood in another vessel. A preferred system using three vessels having a common source of pressurised boiling solution, common condensing (high and low pressure) and solvent recycling means and a common solution make up tank, is described.