林业科学2026，Vol.62Issue(7)：165-175,11.DOI:10.11707/j.1001-7488.LYKX20250484
马尾松早/晚材管胞和纺锤形木射线的湿胀-干缩行为
Wet Swelling and Dry Shrinkage Behavior of Tracheid and Fusiform Wood Ray in Earlywood and Latewood of Pinus massoniana
摘要
Abstract
[Objective]The moisture sorption isotherms and dimensional change ratio in sectional area and the longitudinal,radical and tangential directions of tracheid and fusiform wood ray in earlywood(EW)and latewood(LW)in the same growth ring of Pinus massoniana(masson pine)were real-timely and synchronously investigated.This study aims to reveal the wet swelling-dry shrinkage behavior of EW and LW,providing an important theoretical basis for guiding the efficient processing and utilization of resin-containing pine wood.[Method]The same growth ring of masson pine was used as the research object.The experiment was conducted in the range of 0-98%relative humidity by using Dynamic Vapor Sorption Resolution combined with a video Dino X Lite Digital Microscope.During the adsorption-desorption period,the moisture sorption isotherm and dimensional change ratio in sectional area and the longitudinal,radical and tangential directions of tracheid and fusiform wood ray were synchronously measured.During the period of constant equilibrium moisture content(EMC),whether there was hysteresis between dimensional change ratio and EMC or not was investigated.In addition,the resin content,chemical components,microfibril angle,and porosity of EW and LW were tested using anhydrous ethanol extraction method,National Renewable Energy Laboratory method,X-ray diffractometer,and automatic mercury porosimeter,respectively.[Result]1)Compared to EW,LW had a higher resin content,cellulose and hemicellulose content,as well as lower microfibril angle,porosity and lignin content.2)Under any RH condition,the EMC of EW was greater than that of LW.At 98%RH,the EMC of EW and LW was 17.65%and 16.36%,respectively.3)The absolute hysteresis of EW and LW increased first and then decreased with the increase of RH,with 60%RH as the inflection point.Compared with EW,LW had a more obvious absorption hysteresis phenomenon.4)The dimensional change ratio of tracheid and fusiform wood ray in EW and LW increased/decreased with the increase/decrease of RH.The area change ratio of tracheid was the largest.At 98%RH,the area change ratio of tracheid in EW and LW were 1.117 and 1.181,respectively.Regardless of the tangential or longitudinal direction,the relationship of the dimensional change ratio of fusiform wood ray between EW and LW was opposite to that of tracheid.5)The wet swelling hysteresis of tracheid and fusiform wood ray in EW and LW first increased and then decreased with the increase of RH,with 60%RH as the inflection point,which was consistent with the change pattern of the absolute hysteresis.Compared with EW,LW tracheid and fusiform wood ray exhibited more pronounced hysteresis in wet swelling.6)The dimensional change ratio of tracheid and fusiform wood ray in EW and LW during the EMC constant period was four orders of magnitude lower than that in the moisture adsorption-desorption period.[Conclusion]Compared to EW,the resin content has a greater effect on the water vapor isothermal sorption behavior of LW.The effect of hemicellulose on absolute hysteresis is greater than that of lignin.The dry shrinking/wet swelling behavior of fusiform wood ray is inhibited by the surrounding tracheid.Compared with EMC,the porosity has a more significant effect on the wet swelling hysteresis.The time point at which the parameters of tracheid and fusiform wood ray in EW and LW reach the equilibrium content is consistent with the time point at which the dimensional change ratio is constant,that is,there is no time hysteresis.关键词
马尾松/早材/晚材/管胞/纺锤形木射线/湿胀-干缩/滞后Key words
Pinus massoniana/earlywood(EW)/latewood(LW)/tracheid/fusiform wood ray/swelling-shrinkage/hysteresis分类
农业科技引用本文复制引用
都亚敏,李珠,蒋佳荔,殷方宇,黄鹤..马尾松早/晚材管胞和纺锤形木射线的湿胀-干缩行为[J].林业科学,2026,62(7):165-175,11.基金项目
国家自然科学基金面上项目"基于生长轮尺度的早材与晚材机械吸湿蠕变行为及其互作机制"(32071689)". （32071689）
