Treatment of wood with water-borne preservatives

Abstract

A process for the treatment of wood is disclosed in which water-borne wood treatment materials, such as CCA salts, are forced into the wood under pressure and the water-borne wood treatment materials are held within the wood under pressure until they are deposited as by precipitation or chemical affixation. The precipitation or chemical affixation step is conducted at elevated temperatures. The elevated temperatures may be established by heating the wood treatment materials while they are in contact with the wood, by draining the wood treatment materials from external contact with the wood, while maintaining a sufficient pressure to prevent kickback and heating the wood as by steaming or by submerging the wood in a heated aqueous bath. If a heated aqueous bath is used it may advantageously contain additional wood treatment materials such as wood-softening agents, antichecking agents, filmformers, coloring agents, dimensional stabilizers, flame-retardants, antistatic agents and the like. In a preferred embodiment, the wood is placed under an initial pressure, lower than the impregnation pressure, so that the kick-back is maximized and the liquid retained within the wood is minimized.

Dependencies are inferred from the claim text.