Research On Processing Performance Of Illicium Verum Wood

Illicium verum wood is a characteristic economic forest tree species. However,there were few researches on the wood property, processing performance and application, while more studies on processing and utilization for its fruit. In this paper, Illicium verum wood as research object, its physical and mechanical properties, machining properties, joint strength of frame structure and painting performance were tested comprehensively. The research was aimed to exploring the physical properties of the wood after thinning and regeneration, getting insight into its utilization method and revealing its application to furniture manufacturing, which would provide the scientific theoretical basis and technical support for processing and utilization of the wood. The results were showed as follows:(1) The wood was deemed to reach medium-density level for its basic density as 0.468g/cm3, air-drying density as 0.576g/cm3 and oven-dried density as 0.533g/cm3. The hardness of the cross, tangential and radial face was 5500N, 4050N and 3730N, respectively. The bending strength, modulus of elasticity, longitudinal compressive strength and impact strength was 95.1MPa,7490MPa, 39.2MPa and 29kJ/m2, respectively. The wood was a high-grade timber having the comprehensive strength of 134.3MPa and the comprehensive quality coefficient of up to 2869 X 105 Pa.(2) The fine degree of the finished product of the mechanical processing test was graded according to the American Standard of testing materials (ASTM D1666-87). Score for the wood molding milling, planning, sanding, drilling, turning and mortise processing quality was 4.7,4.8,4.8,4.2,4.5 and 3.1, respectively. And the final total score was 44.9, which evaluated in a fifty-score system of mechanical processing performance. The rest of the projects had demonstrated excellent mechanical processing performance except for the mortise processing.(3) Bonding strength of the node reached the maximum when single rectangular tenon-joint was used. The second was the single elliptical tenon-joint and the minimum was non-through rectangular single tenon-joint. The "T" type of component was superior to the "L" type in the same condition. Results that the furniture component of Illicium verum wood had a relatively strong bonding strength and the strength of the Illicium verum wood was far greater than strength of its component connection, indicated that it could be used as furniture timber.(4) The optimum method for coating polyurethane varnish on Illicium verum wood was that the sanding mesh of 120 mesh (i.e. Ra=4.25), the primed coating dosage of 50g/m2 and the top coating dosage of 30g/m2 was selected and finishing process by three-times primer and three-times topcoat was conducted. The optimum method of coating nitrocellulose varnish was that, the sanding mesh was 240 mesh (i.e. Ra=3.53), the primed coating weight was 30g/m2, the top coating weight was 70g/m2, finishing process selects two primers and two topcoats. The optimum method of coating waterborne wood paint was that, the sanding mesh was 180 mesh (i.e. Ra=4.75), the primed coating weight was 100g/m2, the top coating weight was 60g/m2, finishing process selects two primers and two topcoats. In terms of the gloss of coating on the Illicium verum wood, nitrocellulose varnish was better than waterborne wood paint and polyurethane varnish, the polyurethane varnish as the worst. Besides, the polyurethane varnish and nitrocellulose varnish were obviously superior to the waterborne wood paint in consideration of enhancing color of the coating, of which the polyurethane varnish was the best one.