Study On Wood Properties And Aging Treament Of Toona Sp. Wood (Toona Ciliata M. Roem.)

In this paper,the variation law of anatomical properties,physical properties and mechanical properties of Toona sp.wood was studied systematically,and the influence of tree age on the anatomical properties and physical and mechanical properties of wood was explored.On this basis,the Toona sp.wood was developed.The relationship between physical properties and mechanical properties is discussed.The aging resistance of Toona sp.wood is evaluated by standard artificial accelerated aging and natural aging.The main findings are as follows:As the age of the tree increases,the annual ring width,wood fiber ratio,wood ray ratio decrease,duct length,duct width,duct wall thickness,duct cavity diameter,fiber length,fiber width,fiber wall thickness,fiber cavity The ratio of diameter to catheter and axial parenchyma increased,and the aspect ratio and wall cavity ratio increased first and then decreased.The age of the tube has a significant effect on the length of the tube,the double wall thickness of the fiber,the diameter of the fiber cavity,the ratio of the fiber wall cavity,the ratio of the wood fiber tissue,and the ratio of the wood ray tissue.The width of the tube,the wall thickness of the tube,the length of the fiber,and the width of the fiber.The axial thin-walled cell tissue has a significant effect on the amount of tissue,and has no significant effect on the annual ring width,catheter lumen diameter,and catheter tissue ratio.The Toona sp.wood natural forest has a mature age of about 38 years and is an excellent papermaking.And fiberboard raw materials.With the increase of tree age,full dry density,air dry density,air dry radial shrinkage rate,compressive strength,bending strength,flexural modulus,end face hardness,string hardness,diameter hardness All showed an increasing trend,the total dry radial shrinkage rate increased first and then decreased,chord direction shrinkage rate,volume shrinkage rate,differential dry shrinkage,string swell rate,radial swell rate,volume wet The expansion rate is decreasing.The age of the tree has a significant effect on the total dry density,air dry density,compressive strength,flexural strength,flexural modulus,end face hardness,chord hardness and diameter hardness.The rate reached a significant level,and the effect of total dry chord shrinkage,volumetric shrinkage,radial shrinkage,chordwise swell,radial swell,and volume swell was not significant.The air-dry density is positively correlated with various mechanical indexes,and the correlation coefficient is small.The air-dry density can predict the mechanical properties of red oak wood.After aging of Toona sp.wood,the basic density,volume shrinkage rate,and various mechanical indexes are reduced,which is not only related to the loss of low molecular weight substances such as extracts,inorganic substances and degraded cellulose and hemicellulose.It is also related to the decrease in fiber crystallinity.Before and after aging,the physical and mechanical properties of the heartwood are higher than that of the sapwood,which corresponds to changes in anatomical properties and chemical composition.After the wood is aged,the surface color of both the heartwood and the sapwood changes.