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

Alfredo Huarcaya Paniagua R.; Carolina Yarleque Flores A.; Salvador Segura Rodriguez W. · Proceedings of the LACCEI international Multi-conference for Engineering, Education and Technology (2026) · DOI: 10.18687/laccei2026.1.1.1430

Resumen

This study evaluated the mechanical behavior of wood-plastic composites (WPC) manufactured from recycled high-density polyethylene (HDPE) and pine sawdust without the incorporation of compatibilizing agents. The influence of extrusion temperature and sawdust content on the modulus of rupture (MOR) and modulus of elasticity (MOE), as indicators of flexural strength and stiffness, was analyzed. A full 22 factorial design was applied using two temperature levels (185 °C and 195 °C) and two sawdust contents (10% and 20%), with five replicates per treatment. A total of 20 specimens were tested under three-point bending according to ASTM D790, and the results were analyzed using ANOVA. Both factors showed statistically significant effects (p < 0.01), with sawdust content identified as the most influential variable. The formulation processed at 185 °C with 10% sawdust showed the highest performance within the evaluated range, reaching 28.46 ± 0.64 MPa for MOR and 1849.12 ± 71.74 MPa for MOE. Increasing lignocellulosic content and processing temperature reduced the strength and stiffness of the material, associated with limited interfacial adhesion and thermal degradation of the reinforcement. The results demonstrate that recycled WPCs without additional chemical modification constitute a technically viable alternative for semi-structural applications, such as urban furniture, and for the valorization of plastic and lignocellulosic waste.

Instituciones: Universidad Peruana de Ciencias Aplicadas