Effects of Filler Material on Mechanical Properties of Abaca and Kenaf Fiber Composites

Natural fiber-reinforced polymer composites have gained increasing attention due to their sustainability, lightweight characteristics, and cost-effectiveness. This study investigates the effect of filler materials—fly ash and sawdust—on the mechanical properties of hybrid abaca-kenaf fiber reinforced epoxy composites. Equal weight fractions of epoxy resin and hybrid fibers were used, and the composites were fabricated with and without the inclusion of fillers. Mechanical tests including flexural, tensile, and impact tests were conducted as per ASTM standards. The results showed that the inclusion of sawdust filler improved the flexural modulus and tensile properties compared to other samples, while fly ash significantly enhanced the impact resistance. These findings suggest that appropriate filler selection can tailor composite performance for specific applications.