Design, Optimization, and Mechanical Properties Evaluation of 3D-Printed Auxetic Structures from a Talc-Filled PLA/BioPBS/PBAT Composite for Advanced Engineering Applications

This study investigates the development and optimization of talc-filled PLA, BioPBS, and PBAT composites for 3D printing of high-performance auxetic structures. A Taguchi L9 design of experiments, combined with Grey relational analysis and principal component analysis, was employed to optimize printing parameters, including the nozzle temperature, print speed, and shell number. The optimized 3D-printed composite exhibited strength and stiffness comparable to injection-molded samples, while the impact resistance remained comparatively lower. A star-shaped auxetic structure was printed using the optimized printing conditions and found to exhibit transversely isotropic properties. Compression in the vertical build direction ( XZ plane) resulted in the best performance among the orientations tested with a specific energy absorption of 0.36 J/g and an equivalent plateau stress of 0.61 MPa. The crushing force efficiency varied between 0.52 and 0.58 depending on the load direction. These results demonstrate the potential of the composite for 3D printing of multifunctional, energy-absorbing parts.