摘要
微波处理是开启木材细胞液体流动通道、改善木材浸注性能的重要手段。采用微波对樟子松木材进行处理,并对微波处理工艺进行研究。用体视显微镜及扫描电镜观察宏观裂纹及微观破坏产生的位置,分析裂纹及微观破坏产生的原因,揭示微波处理改善材料液体浸注性能的作用机理。结果显示：微波处理时间90 s,含水率20%~40%是提高樟子松木材液体浸注性能的较优处理条件。体视显微镜及扫描电镜观察发现,微波处理木材宏观裂纹产生的位置主要集中在射线薄壁细胞与轴向管胞的胞间层、轴向管胞复合胞间层及树脂道区域;而显微结构破坏主要存在于射线薄壁细胞与轴向管胞胞间层、轴向管胞上纹孔部位及交叉场纹孔区域。宏观裂纹可增加液体在木材中的流通通道,缩短液体横向渗透路径,提高横向渗透效率。细胞显微结构的破坏,会使液体在细胞间的流通更为通畅,从而改善樟子松木材的液体浸注性能。
Microwave （MW） treatment can be effective to unlock the liquid flow path of wood, and eventually en- hance its liquid impregnate property. The presented study uses MW treatment method. The optimum technological parameters for MW treatment of Pinus Sylvestris L var. lumbers are determined. As macro and micro checks generated in MW treated lumbers, the location of macro and micro checks are identified through stereoscopic microscope, scanned electron microscope （SEM） observation. Besides, the mechanism of liquid impregnate property improvement are uncovered after relating the macro and micro structure changes with liquid impregnate properties for MW treated lumbers. As the experimental results show, MW processing time of 90 s, moisture content of 20% -40% are the optimum technological parameters for MW treat- ment to improve the liquid impregnate properties of Pinus Sylvestris L var. lumbers, while stereoscopic microscope and SEM observation results show that the macro checks generated mainly at compound lamella of longitudinal tracheids, middle lamel- la between ray parenchyma cells and longitudinal tracheids, whereas micro checks are generated between ray parenchyma ceils and longitudinal tracheids, pit border, aspirated pits and cross field pits. Macro checks increase the liquid flow paths and shorten the transverse permeate routes, which improve the permeate efficiency, while microstructure destruction will make the liquid flow between cells more smoothly, thus enhance the liquid impregnate properties of Pinus Sylvestris L var. lumber.
出处
《微波学报》
CSCD
北大核心
2016年第6期90-96,共7页
Journal of Microwaves
基金
林业科学技术推广项目(2014[17]号)
浙江省竹子高效加工重点实验室基金(2014F10047)
关键词
微波
樟子松
宏观裂纹
显微结构
液体浸注性能
microwave, Pinus Sylvestris L. var, macro check, microstructure, liquid impregnate property
