不同干燥方法对杉木人工林木材浸注性的影响

采用高频真空干燥、常规窑干和高温干燥3种方法对杉木人工林木材的心、边板材进行干燥处理,用毛细管上升法评价干燥后试样的浸注性能,用半薄切片法测定干燥试样具缘纹孔的闭塞率,最后用扫描电子显微镜观察干燥试样微观构造的变化,比较分析3种干燥方法对杉木人工林木材浸注性的影响机理.结果表明:对于杉木边材,经高频真空干燥后试样的浸注性显著高于常规干燥和高温干燥后试样的浸注性,后2种干燥方法对试样浸注性影响的差异并不显著;对于杉木心材,高频真空干燥与高温干燥后试样的浸注性存在显著差异,而高频真空干燥与常规干燥之间、高温干燥与常规干燥之间对试样浸注性的影响差异均不显著;3种干燥方法处理后,杉木边材的浸注性均显著高于心材的浸注性;具缘纹孔的闭塞率较低以及部分具缘纹孔周缘破裂是高频真空干燥后木材浸注性提高的主要原因.

Effect of Different Drying Methods on the Liquid Impregnation of Chinese Fir Plantation Wood

Chinese Fir(Cunninghamia lanceolata) plantation sapwood and heartwood boards were treated by radio_frequency vacuum drying(RFVD),conventional kiln drying(KD) and high temperature drying(HT) methods. The maximum amount of dyeing solution uptake by the capillary rise method was used to evaluate the liquid impregnation properties of treated wood. The pit aspiration ratio was determined by semithin section method. Changes in the wood microstructure were investigated using scanning electron microscopy. The results showed that the liquid impregnation of Chinese Fir sapwood after radio_frequency vacuum drying is significant higher than that after conventional kiln drying and high temperature drying,there is no significant difference of liquid impregnation for Chinese Fir sapwood after conventional kiln drying and high temperature drying. The effect of radio-frequency vacuum drying and high temperature drying methods on liquid impregnation of Chinese Fir heartwood is significant,but there is no significant difference of liquid impregnation for Chinese Fir heartwood after radio-frequency vacuum drying and conventional kiln drying,high temperature drying and conventional kiln drying. The liquid impregnation of Chinese Fir sapwood is significantly higher than heartwood after three drying treatments. Low pit aspiration ratio and cracks of some bordered pits are the main reasons for increasing liquid impregnation after radio-frequency vacuum drying treatment.