Comparison of mechanical properties of wood–plastic composites reinforced with continuous and noncontinuous glass fibers

This article presents an experimental investigation on the effect of glass fiber length on the mechanical properties of hybrid wood–plastic composites (HWPCs) manufactured via an extrusion process. There is a substantial interest in enhancing the mechanical performance of WPCs. Incorporation of glass fibers has been found to be an effective remedy in this regard. Theoretically, it is expected that mechanical properties can be improved via applying longer fibers. Three different lengths, 5, 15, and 25 mm of glass fibers were added to the WPC compounds to reinforce WPCs in an extrusion process. In addition, continuous glass fibers were also embedded into the extruded WPC with 70 wt% wood content, utilizing a special equipment in extrusion. Mechanical tests showed that applying noncontinuous glass fibers only marginally improved the mechanical strengths. In contrast, continuous fibers did significantly enhance the final properties of the produced profiles. The glass fiber size was also measured after extrusion, and it was observed that severe fiber breakages occurred during the process, which is the main reason for the inefficiency of noncontinuous fibers. The flexural, tensile, and impact strengths were improved up to 14%, 50%, and seven times in the continuously glass fibers reinforced WPC.