四川德昌地区杉木管胞特征及物理力学性质研究

Tracheid Morphology Characteristics and Physico-Mechanical Properties of Cunninghamia lanceolata Grown in Dechang,Sichuan

【目的】通过研究四川德昌地区杉木(简称"德昌杉木")管胞形态径向变异及物理力学性质,阐明德昌杉木材质特性。【方法】以川西南山地28~34 a德昌杉木为对象,测定管胞长度、宽度、壁厚等形态参数及径向变异。按照国家标准测定分析了密度、抗压强度、抗弯强度、硬度等物理力学性质。【结果】德昌杉木的管胞长度、宽度、双壁厚、腔径、壁/腔分别为:(2.67±0.40)mm、(40.60±8.13)μm、(7.81±1.09)μm、(27.19±3.26)μm、0.31±0.06;全干密度、气干密度、径向干缩系数、弦向干缩系数、体积干缩系数分别为:(0.355±0.03)g/cm^3、(0.382±0.02)g/cm^3、(0.142±0.038)%、(0.208±0.017)%、(0.359±0.03)%;抗弯强度、抗弯弹性模量、顺纹抗压强度、硬度(端面、径面、弦面)分别为:(63.50±4.10)MPa、(9.86±1.71)GPa、(37.52±1.19)MPa、(30.01±0.39)MPa、(18.28±0.39)MPa、(20.86±0.46)MPa。【结论】德昌杉木为轻软木材,约在20 a达到木材成熟龄。与其他地区杉木比较,四川德昌地区杉木物理力学性质性状表现较优。

【Objective】The radial variation in tracheid morphologies and the physico-mechanical properties of Cunninghamia lanceolata grown in Dechang,Sichuan were investigated.【Method】Trees with 28 to 34 years old grown in Dechang Sichuan were harvested as research materials in this work.The tracheid morphologies including length,width,and double cell wall thickness were measured under microscope after the maceration of wood sample.The physico-mechanical properties such as density,compressive strength,MOR,and hardness were measured in accordance with the National Standard Test Method.【Result】The average value of tracheid length,width,double cell wall thickness,lumen diameter and the ratio of cell wall to lumen were(2.67±0.40)mm,(40.60±8.13)μm,(7.81±1.09)μm,(27.19±3.26)μm and 0.31±0.06,respectively.The oven-dry density and air-dry density of wood was(0.355±0.03)g/cm^3 and(0.382±0.02)g/cm^3,respectively.The radial,tangential,and volume shrinkage coefficient from green to oven-dry wood was(0.142±0.038)%,(0.208±0.017)%,(0.359±0.03)%,respectively.The MOR,MOE,compressive strength,and hardness in cross,radial and tangential section of wood were(63.50±4.10)MPa,(9.86±1.71)GPa,(37.52±1.19)MPa,(30.01±0.39)MPa,(18.28±0.39)MPa and(20.86±0.46)MPa,respectively.【Conclusion】Cunninghamia lanceolata wood in Dechang that had higher physico-mechanical properties as compared with the same species from other sites was a light and soft wood matured at about age of 20 years old.