VACUUM-PRESS DRYING OF THICK SOFTWOOD LUMBERS |
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Authors: | H S Jung JH Lee NH Lee |
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Affiliation: | 1. Department of Forest Products , Seoul National University , Suwon, 441-744, Korea E-mail: heesjung@snu.ac.kr;2. Faculty of Forest Science, Chonbuk National University , Chonju, 560-750, Korea E-mail: enamho@moak.chonbuk.nc.kr |
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Abstract: | ABSTRACT In vacuum-press drying of softwood species, wood lemperaiure exhibited a low temperature gradient, and plateau temperature of core lasied during all stages of drying. The drying curves were close to “linear”. The drying rates of the short lumbers were higher for red pine and western hemlock, lower for white pine and similar for larch lumber compared to the long ones. Transverse and longitudinal moisture gradients were small for western hemlock and red pine, and great for larch and white pine lumber. Energy consumption curves were split into three sections: increasing moderately, fairly constant and increasing rapidly. Casehardening stress of dried lumber occurred very slightly. Dried lumbers exhibited strong tendency for fine end checking, slight surface checking and no internal checking. Shrinkage appeared to be low. |
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Keywords: | casehardening stress checks core lemperaiure drying rate energy consumption moisture content distribution shrinkage |
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