Evaluation of Flexural Strength (MOR) and Stiffness (MOE) in Wood–Plastic Composites (WPC) Made from Recycled HDPE and Pine Sawdust (#1430)

Authors

Segura Rodriguez, Wiliam Salvador

Yarleque Flores, Andrea Carolina

Huarcaya Paniagua, Ronald Alfredo

Abstract

This study evaluated the mechanical behavior of wood–plastic composites (WPC) manufactured from recycled high-density polyethylene (HDPE) and pine sawdust. A 2² factorial design was applied to analyze the influence of extrusion temperature (185 °C and 195 °C) and sawdust content (10 % and 20 %) on the mechanical properties. Twenty specimens were tested under three-point bending according to ASTM D790 to determine the modulus of rupture (MOR) and modulus of elasticity (MOE). The analysis of variance (ANOVA) revealed that both factors exerted a statistically significant influence (p < 0.01), with sawdust content being the dominant factor showing high effect sizes (η² = 0.82 for MOR and 0.65 for MOE). Increases in sawdust content and temperature reduced strength and stiffness by an average of −2.8 MPa and −210 MPa, respectively, due to interfacial adhesion loss and thermal degradation of lignocellulosic fibers. The optimal condition of 185 °C and 10 % sawdust achieved the maximum strength (28.46 ± 0.65 MPa) and stiffness (1849.1 ± 72.1 MPa), highlighting the potential of recycled WPCs for lightweight structural applications.