Manufacturing Feasibility Studies on 3D Printable PLA Filament Extrusion by Twin Screw Method and Their Microscopy Studies

Abstract

The increasing demand for composite 3D printing has driven significant interest in the development of advanced composite filaments for prototyping and tooling applications. This study focuses on the fabrication and processability of Polylactic Acid (PLA) composite filaments through twin screw method. A conical twin-screw extruder with four distinct heating zones was employed for melt compounding, followed by water cooling and filament spooling. The extrusion process was carefully optimized to achieve a consistent filament diameter of 1.75 ± 0.05 mm, with the highest extrusion temperature set at 170℃. Optical microscopy analysis confirmed the uniform dispersion of PLA particles across filaments. Rheological studies indicated shear thinning behaviour across all samples at shear rates above 50 (1/s), making them suitable for fused deposition modelling (FDM) 3D printing.