MECHANICAL PROPERTIES OF FOAMED AND UNFOAMED WOOD/PLASTIC COMPOSITES PRODUCED BY EXTRUSION-CALENDERING

摘要

Foamed and unfoamed wood/plastic composites (WPC) were produced by extrusion-calendering. The effect of wood content on the material properties was studied by using different amounts of wood particles (0, 10, 20 and 30%wt). The samples were mechanically characterized in terms of tensile, flexural and impact properties. From the tensile stress-strain curves, three parameters are reported and discussed: modulus, strength and strain at break. For bending tests, only the flexural modulus was studied, while for the impact properties, Charpy impact strength was considered. The results show that foaming induces a global decrease of the mechanical properties, especially for impact and tensile tests, while the addition of wood particles results in higher Young's modulus, but lower strain at break and strength. However, simultaneous wood addition and foaming seems to significantly limit the decrease of mechanical properties in the final material. Finally, as expected, the extrusion-calendering process leads to anisotropic properties; i.e. different results obtained in two perpendicular directions.