Enhancing the Mechanical Performance of Polylactic Acid in Fused Filament Fabrication Using Upcycled Waste Coconut Shell Powder as Reinforcement
摘要
Biodegradable composites for 3D printing have gained attention for incorporating natural fillers that reduce costs and enhance material properties while supporting environmental sustainability. Agricultural by-products such as coconut shell offer an effective way to reuse waste and improve the mechanical behavior of biopolymers like PLA. This study focuses on incorporating 1% coconut shell powder (CSP) into PLA. Filaments were produced using a single-screw extruder, and the effects of print resolution (0.2, 0.3, and 0.4 mm) and printing orientation (flat, base, and edge) on mechanical properties were experimentally evaluated. Mechanical tests were conducted on CSP-reinforced and neat PLA specimens. Tensile strength increased from 8.54 (neat PLA) to 27.56 MPa at 0.4 mm layer height in flat orientation. The elastic modulus improved from 51.48 to 69.01 MPa. Flexural strength increased from 39.3 (neat PLA, P4F) to 44.3 MPa at 0.3 mm in base orientation (CSP). Impact strength improved from 534 to 725 kJ/m2 at 0.3 mm in base orientation. ILSS rose from 26.034 to 32.521 MPa for neat PLA and 29.032 to 36.963 MPa for CSP composite at 0.3 mm in flat orientation. Shore D hardness increased by 12%, with values ranging from 61 (P3B) to 72 D (C2B). Surface roughness peaked at 12.55 µm in edge orientation, inversely affecting tensile strength. Optimal properties were achieved at 0.2 and 0.3 mm resolutions in flat and base orientations. SEM analysis of fractured surfaces confirmed micro-level failure mechanisms.