Thermal effects on bead morphology in fused filament fabrication: A numerical approach to recycled PLA deposition

This study investigates the behavior of recycled PLA during extrusion and deposition processes through numerical simulations and experimental analysis using Differential Scanning Calorimetry (DSC). The thermal analysis characterized key material properties, such as glass transition and melting temperatures, which are critical for optimizing numerical model parameters. The simulation, conducted in a two-dimensional domain using the finite volume method, analyzed the viscous flow of semi-liquid PLA, highlighting cooling effects and viscosity variations. The results demonstrated a stable and uniform deposition process, with a sharp interface between PLA and air and controlled solidification on the substrate. The Cross-WLF viscosity model accurately described the material’s behavior, capturing shear-thinning phenomena and temperature dependency. These findings contribute to the understanding of recycled PLA's performance in additive manufacturing processes, providing insights into optimizing its thermal and flow properties for material extrusion process applications.