Abstract The aim of this study was to evaluate the characteristics of radio-frequency/vacuum combined with mechanical press (RF/VP) drying on three softwood timbers (Douglas fir, Hemlock, and Radiata pine) with longitudinal kerfs. The results were as follows: Due to the dielectric permittivity of wood, RF/VP drying at a fixed frequency of 13.56 MHz significantly influenced the moisture content (MC) distribution, the number of surface checks, shrinkage, and warp. These observations were attributed to the formation of a temperature gradient along the charge plate during the drying. The presence or absence of pith, more affected an occurrence of surface checks than that of the stresses within the wood during drying. The longitudinal kerf reduced the number of surface checks, but did not affect the MC distribution or the twist after drying.

中文翻译：

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射频/真空联合机械压干纵向切缝重质针叶材干燥特性

摘要 本研究的目的是评估射频/真空结合机械压机 (RF/VP) 干燥三种具有纵向切口的软木木材（花旗松、铁杉和辐射松）的特性。结果如下： 由于木材的介电常数，在 13.56 MHz 的固定频率下进行 RF/VP 干燥会显着影响含水量 (MC) 分布、表面检查数量、收缩和翘曲。这些观察结果归因于干燥过程中沿充电板形成的温度梯度。木髓的存在与否，比干燥过程中木材内的应力对表面检查的影响更大。纵向切口减少了表面检查的数量，但不影响 MC 分布或干燥后的扭曲。