TODIM based 3D-Printing Parameter Optimization of Wood-PLA Biocomposite with Bioinspired Infill Pattern

Nature has always been a reliable source of innovation, providing rich and successful solutions for a broad scope of scientific and engineering problems. Drawing from these natural strategies, researchers have developed innovative designs for advanced materials and technologies. In this research, biocomposite samples were fabricated with bio-inspired infill patterns, most notably gyroid and honeycomb structures and using Fused Filament Fabrication (FFF) technique. The printing material was developed by infusing PLA with wood microparticles, a type of industrial/agro-forestry waste, to produce environmentally friendly biocomposites in accordance with the principles of the circular economy. To determine the impact of infill pattern, infill density, and temperature on printing, a Taguchi T9 design of experiment was employed, providing nine distinct printing conditions. Mechanical tests, including tensile, flexural, compressive, impact, interfacial shear strength, and natural frequency, were conducted. The highest tensile strength (86.33 ± 2.83 MPa), tensile modulus (4.98 ± 0.12 GPa), and natural frequency (64.45 ± 2.81 Hz) were observed with rectilinear infill pattern with 100% infill density, 200°C printing temperature and 60mm/sec printing speed (PRC-3). Whereas, the hexagon infill pattern, with 75% infill density, 200°C printing temperature and 40mm/sec printing speed (PRC-5) showed the greatest flexural strength (70.12 ± 3.06 MPa) and compressive strength (53.00 ± 2.66 MPa), while the gyroid infill pattern, 50% infill density with printing temperature of 200°C and 50mm/sec printing speed (PRC-7) showed maximum impact strength (24.69 ± 0.51 kJ/m²) and elongation at break (1.94 ± 0.02%). Because various printing conditions were best under different properties, the TODIM multi-criteria decision analysis approach was employed, and the fifth condition (75% infill density, 200°C printing temperature, 40 mm/s speed, honeycomb pattern) was the best overall. These PLA-wood micro particle biocomposites show significant potential to be sustainable substitutes for conventional materials for industrial and engineering applications.