Fabrication and mechanical-physical characterization of 3D printed PLA-based eco-friendly composites reinforced with jute/banana fiber

Growing environmental concerns over petroleum-based polymers have driven the development of sustainable and biodegradable composites for additive manufacturing applications. In this study, low-weight-fraction jute fiber (JF) and banana fiber (BF) reinforced polylactic acid (PLA) bio-composites were successfully fabricated using Fused Deposition Modeling (FDM) 3D printing technology. Eight different composite formulations were developed using PLA as the matrix material with varying natural fiber compositions (0–1 wt%). The fabricated specimens were comprehensively characterized through tensile testing, hardness measurement, surface roughness evaluation, SEM observation, surface topology and water absorption analysis. The results demonstrated that fiber reinforcement significantly influenced the mechanical and surface properties of the composites. Among all samples, S4 (0.5 wt% JF) exhibited the highest ultimate tensile strength of 46.6 MPa and modulus of elasticity of 892.72 MPa, representing approximately 38.7% improvement compared to pure PLA. Sample S6 (0.5 wt% JF + 0.5 wt% BF) showed the highest hardness value of 79.67 Shore D, while S5 demonstrated the highest toughness of 1.49 MPa. Microstructural analyses revealed improved fiber dispersion, interfacial bonding and reduced void formation in optimized fiber compositions. Surface topology analysis showed that sample S4 had a highly uniform morphology, with 50.00% surface coverage and the highest particle density (0.0003487 particles/µm²) among all samples. Furthermore, all developed bio-composites maintained water absorption below 3%, indicating good moisture resistance and dimensional stability. The results confirm that low-content natural fiber reinforcement enhances the structural performance, sustainability, and processing stability of PLA-based composites for eco-friendly additive manufacturing applications.