欢迎访问林业科学,今天是

林业科学 ›› 2026, Vol. 62 ›› Issue (7): 165-175.doi: 10.11707/j.1001-7488.LYKX20250484

• 研究论文 • 上一篇    

马尾松早/晚材管胞和纺锤形木射线的湿胀−干缩行为

都亚敏,李珠,蒋佳荔*(),殷方宇,黄鹤   

  1. 中国林业科学研究院木材工业研究所 国家林业和草原局木材科学与技术重点实验室 北京 100091
  • 收稿日期:2025-08-02 修回日期:2026-05-11 出版日期:2026-07-10 发布日期:2026-07-14
  • 通讯作者: 蒋佳荔 E-mail:jialiwood@caf.ac.cn
  • 基金资助:
    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)”。

Wet Swelling and Dry Shrinkage Behavior of Tracheid and Fusiform Wood Ray in Earlywood and Latewood of Pinus massoniana

Yamin Du,Zhu Li,Jiali Jiang*(),Fangyu Yin,He Huang   

  1. Key Laboratory of Wood Science and Technology of National Forestry and Grassland Administration Research Institute of Wood Industry, Chinese Academy of Forestry Beijing 100091
  • Received:2025-08-02 Revised:2026-05-11 Online:2026-07-10 Published:2026-07-14
  • Contact: Jiali Jiang E-mail:jialiwood@caf.ac.cn

摘要:

目的: 实时、同步测定马尾松同一生长轮内早/晚材的水分吸附等温线及其管胞和纺锤形木射线的截面积和轴、径、弦3个主方向的尺寸变化比率,揭示早/晚材管胞和纺锤形木射线的湿胀?干缩行为规律,为指导含脂松树木材的高效加工与利用提供重要理论依据。方法: 以马尾松同一生长轮内早材和晚材为研究对象,利用动态水分吸附分析仪联用视频白光显微镜,在0~98%相对湿度范围内进行试验:在水分吸着?解吸阶段,同步测定早/晚材的水分吸附等温线及其管胞和纺锤形木射线的截面积和轴、径、弦3个主方向的尺寸变化比率;在平衡含水率恒定阶段,考察尺寸变化比率与平衡含水率之间是否存在滞后现象。应用无水乙醇抽提方法、美国国家可再生能源实验室方法、X射线衍射仪和全自动压汞仪分别测定早材和晚材的含树脂率、化学组分含量、微纤丝角和孔隙率。结果: 1) 与早材相比,同一生长轮内晚材具有较高的含树脂率、纤维素和半纤维素含量,较低的微纤丝角、孔隙率和木质素含量;2) 在任一相对湿度,早材平衡含水率均大于晚材;在98%相对湿度时,早材和晚材平衡含水率分别为17.65%和16.36%;3) 早材和晚材的绝对滞后值均随相对湿度升高呈先增大后减小的变化趋势,以60%相对湿度为拐点;相较于早材,晚材具有更明显的吸湿滞后现象;4) 早/晚材管胞和纺锤形木射线各参数的尺寸变化比率均随相对湿度升高/降低而增大/减小,其中管胞截面积变化比率最大,在98%相对湿度时,早材和晚材管胞截面积变化比率分别为1.117和1.181;无论是弦向还是轴向,纺锤形木射线在早材和晚材之间的尺寸变化比率关系与管胞相反;5) 早/晚材管胞和纺锤形木射线各参数的湿胀滞后值均随相对湿度升高呈先增大后减小的变化趋势,以60%相对湿度为拐点,与绝对滞后值的变化规律相同;相较于早材,晚材管胞和纺锤形木射线具有更明显的湿胀滞后现象;6) 早/晚材管胞和纺锤形木射线各参数在平衡含水率恒定阶段的尺寸变化比率与水分吸着?解吸阶段相比低4个数量级。结论: 相较于早材,树脂含量对晚材水分等温吸附行为影响更大;相较于木质素,半纤维素对绝对滞后值影响更显著;纺锤形木射线湿胀?干缩行为受周围管胞的抑制作用;相较于平衡含水率,孔隙率对湿胀滞后值影响更显著;早/晚材管胞和纺锤形木射线各参数达到含水率平衡态的时间点与尺寸变化比率恒定的时间点一致,即不存在时间滞后现象。

关键词: 马尾松, 早材, 晚材, 管胞, 纺锤形木射线, 湿胀?干缩, 滞后

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.

Key words: Pinus massoniana, earlywood (EW), latewood (LW), tracheid, fusiform wood ray, swelling-shrinkage, hysteresis

中图分类号: