Basic knowledge of wood drying

Wood drying method refers to the use of natural and artificial force for wood moisture evaporation dissipation, make the moisture content of lumber moisture content down to conform to the requirements of the use, avoid the wet material in the process of storage, transportation and use of hyphal erosion and wood splitting, deformation and improve the quality of wood products to extend the service life.
Natural lumber drying method is a kind of using gas convection drying.Artificial convection heating and drying methods are so important in the dielectric heating, the former has a dry kiln, solar drying, drying too dry and water liquid centrifugal force;The latter has a microwave drying, high frequency drying.And infrared radiation heating drying and belong to contact heating drying.Both at home and abroad is given priority to with convection heating air drying and kiln dried, especially dry kiln as the major method.
Wood drying is first wood surface evaporation, the moisture content of surface layer is lower than the wood interior, internal moisture move to the surface under the effect of moisture content gradient.At the early stage of the drying speed depends on the speed of wood surface evaporation, the middle and late drying, drying speed depends on the internal moisture movement speed, is inversely proportional to the plate thickness and wood specific gravity.In addition, sapwood drying speed is faster than heartwood.The strings of the hard wood panel dry faster than diameter panel;But softwood string diameter surface no obvious difference.Tree species for drying effect, easy dry wood have Korean pine, scales spruce, fir, pine, fir, red one spruce, masson pine, fir, mongolica, basswood, paulownia, polishing the wood;Not easy to dry wood have cypress wood, color wood, maple wood, yellow pineapple, walnuts, camphor, catalpa wood, Chinese catalpa, elm katus, persimmon, liquidambar, etc;Difficult to dry wood are larch, manchurian ash, beech, cyclobalanopsis, German oak, lotus, cocobolo wood, oak, oak, etc.