Mode I fracture toughness of oil palm fiber-reinforced ABS composites fabricated using fused deposition modeling

This study investigated the Mode I fracture toughness and impact behavior of oil palm fiber (OPF)-reinforced acrylonitrile butadiene styrene (ABS) composites fabricated using fused deposition modeling (FDM). Composite filaments containing 3, 5, and 7 wt% OPF were produced and used to fabricate test specimens. Mode I fracture toughness was evaluated using single-edge notched bend specimens, while impact performance was assessed through impact testing. The results demonstrated that fiber loading significantly influenced crack propagation resistance and energy absorption. The 3 wt% OPF composite exhibited superior fracture toughness and impact strength, attributed to improved stress transfer and more homogeneous fiber dispersion within the ABS matrix. Conversely, higher fiber contents, particularly 7 wt%, reduced toughness due to fiber agglomeration, poor interfacial bonding, and increased stress concentration sites that promoted crack initiation and propagation. Fractographic analysis revealed matrix cracking, fiber pull-out, and interfacial debonding as the predominant failure mechanisms. These findings indicate that OPF is a promising sustainable reinforcement for FDM applications, provided that fiber loading is carefully optimized.