Investigation of tensile properties of FDM-printed PLA-CF infill in PLA shell components

This research examines the parametric optimization of dual-material sandwich tensile specimens produced by Fused Deposition Modelling (FDM), utilizing Polylactic Acid (PLA) for the outer shell and Carbon Fiber Reinforced PLA (PLA-CF) for the infill. Through the use of a Taguchi L9 orthogonal array design, the effects of layer height, infill density, and infill pattern on mechanical properties and fracture morphology were assessed. The results indicate that a layer height of 0.30 mm, a concentric infill pattern, and an infill density of 90% produce the highest ultimate tensile strength (41.82 MPa) and Young’s modulus (780.72 MPa), attributed to enhanced interfacial bonding and fiber dispersion. Scanning electron microscopy (SEM) analyses validate pristine PLA/PLA-CF interfaces and consistent carbon fiber distribution in optimized samples, with grid patterns notably augmenting ductility. The research concludes that the strategic selection of FDM parameters facilitates the creation of robust, lightweight, and high-strength PLA/PLA-CF sandwich structures appropriate for advanced engineering applications.