Study On The Wood Property And Painting Properties Of Tsoongiodendron Odorum Plantation

In order to provide scientific argument for comprehensively understanding the basic wood properties of Tsoongiodendron odorum plantation wood, promoting its utilization,27years old Tsoongiodendron odorum plantation wood were used as testing materials and its wood drying characteristics, anatomical properties,main physico-mechanical properties and painting properties technology were studied.The main results of this study are as follows:(1) The drying characteristics of Tsoongiodendron odorum timber is good, its drying speed is2grade, faster; Its volumetric drying shrinkage coefficient is between0.36%-0.45%,belong to small;The main drying defects are the twist deformation and initial crack, and this two defects level have reached level3.The rest of the drying defects are relatively light, no internal cracking.(2) The microfibril angle of Tsoongiodendron odorum timber is in9.6～20.3°,the average value is10.5°,and its coefficient of variation is14.16%;The average of fiber length, fiber lumen diameter,fiber diameter, fiber wall thickness,fiber length-diameter ratio,fiber thickness-lumen ratio, fiber lumen-diameter ratio of Tsoongiodendron odorum timber are respectively1367.47μm,17.87μm,27.26μm,9.39μm,51.86,0.57,0.65. At longitudinal variation, fiber length, fiber diameter, fiber lumen diameter, fiber lumen-diameter ratio all shows that they increasing gradually upward along the trunk to a certain height and then slowly become smaller, microfibril angle,fiber wall thickness and fiber thickness-lumen ratio are firstly decreasing and then increasing, the rule of fiber length-diameter ratio is not obvious;At radial variation,except for the fiber lumen-diameter ratio, microfibril angle, the remaining indexs all shows that they increasing gradually since the pith outward to a certain age then tending to be stable,and this trend is most visible in fiber length and fiber wall thickness’s change. At radial variation,the fiber lumen-diameter ratio is reduced gradually from pith outward first and then tends to be stable, the microfibril angle increases rapidly at first then decreases rapidly,after a certain age, the decreasing trend becomes very slow and gradually turns to be stable.(3)The average for annual ring width of Tsoongiodendron odorum timber is4.25mm and the maximun width is12.70mm;The basic density of Tsoongiodendron odorum timber is in0.344～0.488g/cm3,the average value is0.417g/cm3and its coefficient of variation is7.74%.;The average for air-dried density and oven-dried density of Tsoongiodendron odorum timber are respectively0.463g/cm3,0.426g/cm3; From the wet material to air dried, the dry shrinkage rates of radial,tangential,volume of Tsoongiodendron odorum timber are respectively0.82%,2.02%and3.02%; From the wet material to oven dried, the dry shrinkage rates of radial,tangential,volume of Tsoongiodendron odorum timber are respectively3.06%,5.92%and10.21%,the difference shrinkage is1.93,moderate;From oven dried to air dried, the wet-swelling rates of radial,tangential,volume of Tsoongiodendron odorum timber are respectively1.07%,1.67%and2.96%; From oven dried to wet material, the wet-swelling rates of radial,tangential,volume of Tsoongiodendron odorum timber are respectively3.10%,6.37%and10.42%.(4)The hardness of end surface,tangential surface and radial surface of Tsoongiodendron odorum timber are respectively4366.21N,3061.63N and2748.19N, the hardness of tangential surface and radial surface is soft, the hardness of end surface reaches to medium;The bending strength,modulus of elasticity,compressive strength parallel to the grain and impact toughness of Tsoongiodendron odorum timber are respectively79.79MPa,6517.88MPa,42.38MPa,26.01KJ/m2.Among them, the impact toughness is very low, the other indexs are low.(5)The best finishing technology of polyurethane paint for Tsoongiodendron odorum timber is:2.5μm surface roughness,a primer coating amount is30g/m2,a topcoat coating amount is70g/m2,primer brushing for2times and topcoat brushing for3times;The best finishing technology of water-based wood paint for Tsoongiodendron odorum timber is:2.5μm surface roughness,primer coating amount is100g/m2,topcoat coating amount is80g/m2,primer brushing for3times and topcoat brushing for3times(6)The comprehensive wood quality coefficient of Tsoongiodendron odorum timber is2908.81×105Pa,belongs to high grade material. The boundary between juvenile wood and mature wood of Tsoongiodendron odorum plantation is defined to be10a by cluster analysis.