Study On Aging Resistance Of Wood Residues Composites

The use of wood residues is increasingly urgent, because recoverable forest resources are decreasing and serious shortage of reserve resources in china. Wood residues is a valuable resource, its rational use is a necessary condition for sustainable forestry development. While the service life of materials and products are research and design use issues of common concern. For a newly developed product, people are expected to use accelerated aging method in test room for a short time to obtained experimental data predicted, estimate the life of materials and products. This research focuses on wood residues composites, which is with mixed wood residues as filling material, with glass fiber, bamboo pieces as reinforcement, with phenolic resin as matrix material, with coupling agent as surface modification additives, with paraffin emulsion as water repellent manufactured. This paper according to ASTM D1037 accelerated aging method and regression analysis, orthogonal experiments, range analysis and variance analysis, also used scanning electron microscopy to analyze the test results. The main contents include aging resistance of four different components of the structure wood residues composites; the effect of processing parameter on aging resistance of wood residues composite; the effect of UV absorber on the surface of wood residues composites by UV accelerated aging.Through test and analysis get the following conclusions:the aging resistance performance of component structure IV is best, followed by is the component structureⅢ, the worst for the component structure I, from MOR, MOE, compression strength parallel to grain and 24h thickness swelling of the point of view. Thus determine the optimal component structure is IV, after aging the MOR, MOE, compression strength parallel to grain retention rate was 82.87%, 82.74%,84.60%, and its thickness swelling after 24-hours water absorption changes in the 6% to 11%. Regression analysis of the main mechanical properties of the component structure IV, used curve Estimation to fit, degree of logarithmic curve fitting is better than the exponential curve fitting. Processing parameter had influence on MOR,MOE compression strength parallel to grain and thickness swelling after 24-hours water absorption before and after accelerated aging. Comprehensive consideration suggested that the optimum processing parameters(hot-pressing temperature, glue consumption and hot-pressing time)should be 140℃, 14.0%,0.7min/mm.The not add any additives wood residues composites surface cracking phenomenon is more serious after UV accelerated aging 1000h and 2000h, adding UV absorbers wood residues composites compared to not added, the surface layer off phenomenon of surface was not found, and the phenomenon of surface cracking have a significant reduction.