The Performance And Application Of Heat-treated Small Diameter Eucalyptus Multi-interface Panel

Based on the increasingly prominent contradiction between the supply and demand of wood materials at this stage,the rational development and utilization of fast-growing timber and the realization of large-scale use of small timber and inferior timber are one of the important methods to effectively alleviate the prominent contradiction between supply and demand of timber resources in our country.This article takes the small-diameter eucalyptus wood panel as the research object,through exploring the influence of different heat treatment processes on the general color,dimensional stability,mechanical strength and internal chemical structure of the small-diameter eucalyptus wood panel,to obtain the best panel plan and the best heat treatment process.This research focuses on the development and application of the product.The optimal plan in the above process is named the small-diameter eucalyptus multi-interface composite panel,and its basic physical properties are tested and simulated by the finite element method.Load tests are carried out on the joint members of the L-shaped and T-shaped furniture corners of the panel to explore the failure loads and forms of different connection methods.At last,according to the above research results,the small-diameter eucalyptus multi-interface composite panel is used for furniture design practice,and finished products are made.Starting from the fast-growing small-diameter wood,this study explores ways to effectively improve the high-value utilization of small-diameter eucalyptus solid wood,which has reference significance for improving the utilization of small-diameter wood,and provides a reference for the multi-interface composite process of small-diameter eucalyptus.The main conclusions are as follows:(1)The overall color difference of the small diameter eucalyptus wood panels before and after heat treatment tends to increase with the increase of temperature and time;thermal modification treatment can effectively improve the dimensional stability of small diameter eucalyptus wood panels.In terms of bonding strength,the shear strength of heat-treated material decreases with the increase of temperature.At the same temperature,the shear strength of the two-tooth panel is the largest.Considering comprehensively,this study shows that the small diameter eucalyptus two-tooth splicing plan is the best splicing plan,and heating at 160?for 2 h is the best heat treatment process.(2)The mathematical relationship between the small diameter eucalyptus plywood bonding area,the processing temperature and the shear strength is established.Establish the relational expressions of the heating law of the three tooth shapes of small diameter eucalyptus plywood under the condition of 160?.(3)The physical properties of the small diameter eucalyptus multi-interface composite panel were investigated with reference to the corresponding national standards.The air-dry density is 0.503 g/cm~3,the moisture content is 5.3%,the longitudinal bending strength is 92.1 MPa,and the longitudinal bending elastic modulus is 12780 MPa,and the formaldehyde emission is 0.02 mg/L.The material parameters of the panel are tested,9 engineering constants are measured and calculated,and the finite element method is used to simulate the bending strength of the panel.(5)In the mechanical strength test of the L-shaped and T-shaped furniture corner joint components of the panel,the mechanical properties of the tenon-and-mortise structure connection method are better.The damage load of the full-permeable dovetail joint is the largest,followed by the semi-permeable dovetail joint,and the damage load of the round bar joint and the eccentric connector is relatively small.The breaking load of T-shaped members of the same type of joint is higher than that of L-shaped members.(6)Using small diameter eucalyptus multi-interface composite panel as the material,carry out the design practice of new panel product application,design two small furniture,new Chinese style bedside table and tea table,and complete the production by the company.