This study investigated the mechanical characteristics of components produced from composite Polylactic Acid reinforced with Carbon Fibers (PLA-CF). PLA and PLA-CF were produced with strict rules regarding layer thickness, nozzle diameter, printing speed, and orientation. PLA-CF exhibited superior tensile characteristics, Izod impact test values, and higher crystalline degree than PLA. Samples with density values of 20%, 40%, 60%, 80%, and 100% were tested for ultimate tensile strength. It was shown that the PLA-CF UTS samples at 100% infill density (45.292 MPa) surpassed the PLA samples (42.235 MPa). As the strength values increased, the Izod impact strength followed the same pattern with infill density. The Grey Relational Analysis (GRA) approach was employed to optimize the infill density in order to enhance the dimensional accuracy. The aforementioned parameter was found to have a more significant influence on product quality and time reduction in the Fused Filament Fabrication (FFF) process.

Additive manufacturing (AM), particularly Fused Deposition Modeling (FDM), has revolutionized polymer-based fabrication through design freedom and material efficiency. This work presents a comprehensive statical optimization of FDM parameters affecting the flexural properties of acrylonitrile/butadiene/styrene (ABS) specimens. The effects of layer thickness (0.15–0.25 mm), infill density (30–70%), printing speed (35–95 mm/s), and build orientation (Flat, On-edge, Vertical) were investigated following ASTM D790 standards. A Taguchi L9 orthogonal array coupled with ANOVA analysis was employed to quantity parameter significance. According to the ANOVA analysis, infill density was identified as the most influential parameter, accounting for 61.3% of the variation in flexural strength (σ_f) and 60.1% in flexural modulus (E_b). The optimal configuration (0.25 mm layer thickness, 70% infill, 65 mm/s speed, horizontal orientation) yielded a flexural strength of 84.9 MPa and modulus of 2.54 GPa. Microstructural observations confirmed that higher infill and moderate speed improved interlayer fusion and reduced void formation. The developed Taguchi–ANOVA framework offers quantitative insights for tailoring process–structure–property relationships in polymer-based additive manufacturing.