Design And Creep Performance Of Creep Testing Device For Wood-plastic Composites

With the continuous improvement of public awareness of environmental protection,many areas have begun to use wood-plastic composite materials,and wood-plastic composite materials in certain environmental conditions will produce creep deformation,resulting in wood-plastic composite material structure has changed greatly,Resulting in a rupture,which could lead to a safety accident.Therefore,it is very meaningful to study the creep characteristics of wood-plastic composites in specific environment?In this paper,the ratio of raw materials and the parameters of the wood-plastic composites were tested by orthogonal test,and the wood-plastic composites were prepared by extrusion molding method using poplar powder and polyethylene as the main raw materials.Using the internationally accepted ASTM standard,the bending strength of wood-plastic composites was tested by three-point bending loading test.The influence of different ratio of raw materials and process parameters on the flexural strength of wood-plastic composites was analyzed by means of range method.The effects of granulation temperature,coupling agent and wood-plastic ratio on the flexural strength of wood-plastic composites were significant.In this paper,we designed the wood-plastic composite creep test device,which ensures the load applied to the specimen and the constant temperature and relative humidity values around the specimen.The parameters of load,temperature and relative humidity of the parameters of wood-plastic composites were tested by orthogonal test.The creep test was carried out on the wood-plastic composites by using the test equipment.The creep data were processed and analyzed by means of the difference method and variance analysis method.The creep trend of the specimen was analyzed and the influence of load,temperature and relative humidity on the creep strain of the wood-plastic composite was analyzed.The effect of parameter load and temperature on the creep performance of wood-plastic composites is significant and the relative humidity has no significant effect on the creep performance of wood-plastic composites.The creep trend of wood-plastic composites was fitted by ten-element model and power-law function model.The model fitting curve is very similar to the actual creep curve.The ten-element model and the power-law model are very high for the creep fitting of the wood-plastic composites,and the fitting degree of the power-law model is higher than that of the ten-element.