Optimization of processing parameters for enhanced tensile performance of 3D-printed TCNP reinforced PLA composites

• PLA-TCNP composite achieved 50.51 MPa tensile strength at optimal conditions. • 0° orientation provided the best load transfer and highest mechanical properties. • 90 % infill density enhanced stiffness, strength, and reduced porosity in composites. • Cross-head speed, orientation, and infill density influence tensile strength (R² = 0.9803). • PLA-TCNP composites are promising for high-performance engineering applications. This research aims at examining the mechanical behaviour of PLA based composites reinforced with terminalia chebula nanoparticles (TCNP) through 3D printing. Tensile specimens were printed by FDM at a printing rate of 50mm/s and tested for tensile strength under different orientations (0°, 45°, 90°) and infill densities (30 %, 60 %, 90 %) at a cross-head speed of 3 mm/min, 6 mm/min, 9 mm/min. The results revealed that tensile strength is significantly influenced by orientation, infill density, and Cross-Head speed, with the highest tensile strength of 50.51 MPa achieved by a 95PLA:5TCNP composite at 3 mm/min Cross-Head speed, 0° orientation and 90 % infill, which possesses the best tensile strength. Higher infill percentages led to higher stiffness and strength, and lower porosity due to reduced pore volume, but also to reduced strength when the fibers were not aligned at 0°. The greatest effect was observed in the aspect of orientation where 0° orientation offered the best load transfer as a result of aligned layers while 90° orientation offered the weakest properties as a result of interlayer delamination. These findings highlight the potential of PLA with the TCNP composites especially at 0° fiber orientation and 90 % infill for high performance engineering applications. Furthermore, a regression model showed that the values of cross-head speed, orientation and infill density significantly affect the tensile strength with R squared value of 0.9803, further validating the ability of the material to achieve its enhanced mechanical performance.