subject: Method For Drying Wood [print this page] An improvement in the drying of wood which allows wood drying equipment at an equal or faster than conventional rate with less degrade, fewer stresses, and less total shrinkage, comprising treating the wood prior to drying with a material capable of reducing the interfacial tension at the water-air boundaries in the cell structure of the wood. Preferably the wood is treated with an aqueous solution of a non-volatile surface active agent, such as an alkylarylsulfonate.
The process of this invention can be most easily carried out by spraying, dipping, brushing, etc., an aqueous solution of a surface-active agent on the surfaces of the wood to be dried. When only the surfaces of the wood dry equipments are treated, the surfactant does not penetrate very deeply into the wood. This is probably because wood does not have a continuous water phase which is necessary for migration of the surfactant. By suitable known techniques, however, the wood can be treated, if desired, so that the surfactant or surfactants will be substantially completely diffused throughout the wood although this is not ordinarily necessary. It is thought that the aqueous solution containing the surfactant, when used to treat wood dry equipments surfaces, penetrates a short distance into the wood surfaces and fills parts of the lumens and particularly the pits connecting lumens with adjacent lumens, and lumens with transverse ray cells with the low surface tension liquid. The pit openings and cell passages in the wood are pulled shut by forces generally present during drying of the wood, with water evaporating from the surfaces of the wood when surfactants are not present. Surface stresses are reduced during the early stages of drying by the action of surfactants and, because more of the cell passages are open, drying proceeds at a faster rate with reduced structural degrade.
The wood, after treatment with the surfactant, can be dried by conventional wood drying equipment techniques. Best results are obtained if the wood is subjected to treatment with the surface-active agent or agents as soon as possible after exposure of a freshly cut surface. By doing so, reduction of stress and degrade which take place during yard storage, and/or yard drying, is accomplished.
