摘要:Highly dimensionally stable particleboards of spruce and Birch were exprimentally made from chips treated with saturated at elevated pressures. The relationships between steam pressure. time of steam treatment and MOR, MOE, IB and thickness swelling, linear expansion of particiebohrds were studied. The results indicated that the optimal technique parameters of steam treating chip were steam pressure: 1.3N/mm~2, steam treating time: 5~6 min, and the stability of the Birch particleboard by steam treated was much greater than spruce.
摘要:In this article, the surface finishing of gypsum particlehoard is studied Three kinds of overlay material, Such as wood veneer, melamine resinimpregnated paper and polyvinyi chloride(PVC) film were used in the experiment. The interal bonding strength of the layers of the overlayed boards were tested, and result was satisfactory.
摘要:Lemon eucalyptus is one of the fast-growth species in southern China, but its utilization has not been explored completely. The object of this paper is to find the possibility of manufacturing cement-bonded particleboard by lemon eucalypttis, and some technical factors, such as the hydration chracteristics of the wood mixed with cement, ratios Of cement to wood as well as the type of cement were analysised. The results showd that the lemon eucalyptus is suitable for manufacturing cement-bonded particleboard by adding certain chemical additive or treating by hot water although the water, extractive of the wood Can retard the setting of cement; the optimum parameter of cement/wood ratio is 2.5 and the properties of the board by using cement type 525 is better than 425.
摘要:The method of gradient transformation was initialized in the paper. The diffusion coefficient in the governing differential equation of mass transfer and the surface emission coefficient on the boundary condition were experimentally determined. The effect of undersurface evaporation was quantitatively analyzed. The relationship between relative evaporation rate and the relative depth of evaporation surface was given. The experiment showed that the relative depth of evaporation below 1% influenced the relative evaporation rate significantly. The surface emission coefficient was also a function of the relative depth of evaporation.* The diffusion coefficient was a function of moisture content. By taking into account of the dependent of the above mentioned coefficients on the relative depth of evaporation and moisture content, the reliability of the given coefficients was tested by using the analytical solution of the governing differential equation of mass trapsfer. This showed a deviation in less than 6 between the measured values and the calculated values, which posed the results of the study as a valid exploring.
关键词:Wood chips;Method of gradient transformation;Coefficient of water movement
摘要:It is possible to use only UF resin as the adhesives for interior moulded wood products. However, when the products are for exterior use, it is difficult to achive satisfactory performance in water resistance, even if the normal level of wax is added. The modified MF resin (MS-03) was mixed into the UF resin to reduce the thickness swelling and enhance water resistance. The products can be used under hot and damp weather condition in the southern china area.