Research On Preparation And Properties Of Wood Plastic Composites For Furniture Application

As a green material,wood-plastic composite has a broad application prospects.But there are still many problems with wood-plastic composites,such as high material cost,hard to decorate,high density and poor nail-holding ability,which limit its application in the field of furniture.Considering the physical and mechanical properties of wood-based panel,this paper focuses on improving the physical and mechanical properties of wood-plastic composites.Several polyolefin-based wood fiber reinforcement composites with high wood fiber content were prepared,including foamed WF/high density polyethylene(HDPE)composites by hot pressing,WF/polypropylene(PP)and WF/low density polyethylene(LDPE)composites by mould pressing and hot pressing,and veneer covered wood-plastic composites.The effect of foaming agent amount,wood fiber content and forming methods on the physical and mechanical properties of wood-plastic composites were studied.(1)The measurement results of foamed WF/HDPE composites shows that with the increase of foaming agent amount and wood fiber content,the density of the composites reduced,the water resistance and the mechanical properties decreased.SEM images show that the interface bonding of the composites were weakened,and the number of cells increased but the uniformity of cell size became worse.When the amount of foaming agent reached 10 parts,the flexural performance and tensile properties of the foamed composites were good,whereas the impact strength were low and the density did not meet the requirements of wood-based panel.(2)WF/PP and WF/LDPE composites were prepared by hot pressing.The density,moisture absorption,contact angles,surface energy,mechanical properties,dynamic thermomechanical properties,internal bonding strength and surface bonding strength of these composites were measured.When the wood fiber content varied from 50% to 90%,and to observe the microstructure of the composites by SEM.The results showed that with the increase in wood fiber contents,the wettability of the composites were improved,however,the mechanical properties and surface bonding strength decreased.This is because when the wood fiber content increased,accordingly,the nonpolar plastic substrate decreased,so that the surface free energy of the composites increased.And in the case of high wood fiber content prone to fiber agglomeration phenomenon,the composite interface weakened,so each performance reduced.When wood fibers reached 80% level,the composites still remained good physical and mechanical properties.The surface wettability and the mechanical properties of WF/PP composites were better than those of WF/PE composites.(3)The WF/PP composites were prepared by compressing in mold.Their properties were compared to those of hot pressing composites.The results indicated that hot pressing method showed better wettability,mechanical properties and surface bonding strength.And hot pressing method has potential advantage in terms of surface covering decoration.(4)When WF/PP and WF/PE composite were laminated with wood veneer the resulted boards met the physical and mechanical property requirements of wood-based panel.The research of veneered wood plastic composites indicates that the water resistance,flexural strength and elasticity modulus,surface bonding strength and nail-holding performance of veneered wood plastic composites were better when wood fiber content was 70%.Compared to PE-based veneer composites,the physical and mechanical properties of PP-based veneer composites were better.