This study aims to evaluate the effect of a wide range of printing speeds (50–500 mm/s) on the mechanical performance and production efficiency of polylactic acid (PLA) specimens produced by fused filament fabrication (FFF). It specifically addresses the underexplored behavior of PLA at high printing speeds exceeding 300 mm/s. Using high-speed PLA filament, specimens were fabricated via FFF at a constant extrusion temperature of 230°C to isolate the influence of printing speed. Tensile testing was performed to assess mechanical properties, and manufacturing time was recorded. Normalized tensile strength and elastic modulus were calculated to reflect the balance between performance and production efficiency. Increasing the printing speed from 50 to 150 mm/s improved tensile strength by 11.55% and elastic modulus by 8.4%, while reducing manufacturing time by over 60%. The elastic modulus reached a local maximum of 1332.55 MPa at 250 mm/s, with stable tensile strength in the 200–300 mm/s range. At 500 mm/s, the elastic modulus peaked at 1628.73 MPa, the highest among all tested speeds. Normalized metrics indicated significant gains in efficiency at lower speeds with only modest reductions in mechanical performance. To the best of the authors’ knowledge, this study provides the first comprehensive investigation of PLA tensile behavior at FFF printing speeds up to 500 mm/s. The findings offer practical guidance for optimizing FFF process parameters to achieve a tradeoff between mechanical strength and rapid production, which is critical for industrial-scale high-speed 3D printing applications.
