杨木厚单板连续热压干燥的研究

Research on Continuous Platen Drying of Poplar Thick Veneer

研究了以导热油作载热体，采用高温（１７０℃）连续热压干燥的方法，干燥美洲黑杨厚单板。可在４ｍｉｎ内，将３ｍｍ厚的生材单板干至５．１％的终含水率。干单板平整、光滑、终含水率均匀，无撕裂。单板厚度干缩率平均为６．８％，高于网带传送对流干燥的单板３．３％；横纹于缩率４．８％，低于对流干燥的单板７．９％。研究结果表明，此法干燥速生杨木单板是可行的，用此厚单板压制的单板层积材（ＬＶＬ）已出日到日本。

High temperature (170℃) continuous platen drying of Cottonwood thick veneer was re- searched with heat-conducting oil as heat medium. 3mm thick green veneer could be dried to final mois- ture content 5.1% in 4 min and the dry veneer was smooth, flat with even final moisture content and without split. The average thickness shrinkge rate (6. 5%) is higher than that of convection drying (3.3%) and cross-grain shrinkge rate (4.8%) is lower than that of convection drying 7. 9 %. The re- search results showed that drying thick veneer of fast growing poplar with the above method was feasi- ble. The laminated veneer lumber(LVL) plied with the thick veneer was exported.