A STUDY ON THE PHYSICO-MECHANICAL PROPERTIES OF CHINESE FIR(CUNNINGHAMIA LANCEOLATA)IN YUNNAN-THE PHYSICO-MECHANICAL PROPERTIES OF CHINESE FIR IN YILIANG

This paper reports the physico-mechanical properties of Chinese fir grown in Yiliang,and concludes that its latewood percentage and air-dried density are higher than that grown in other regions of Yunnan while its compression strength parallel to grain, bending strength,maximum tensile strength parallel to grain etc.have distinct reduction so that they are neither in accordance with the interrelation between the density of wood and mechanical strength of wood,nor the regression equation for the wood density value and mechanical strength value. The authors have also measured fibril angle of wood fiber cellulose walls of Chinese fir grown in both Yiliang and Xichou.The result has shown that fibril angle of wood fiber cel-lulose walls of Chinese fir grown in Yiliang is 9.7° bigger than that grown in Xichou,and that the compression strength parallel to grain bending strength,maximum tensile strength parallel to grain etc.of Chinese fir are obviously reduced while the fibril angle be-comes enclarged.