Effect of Printing Pattern on the Mechanical Properties of 3D Printed PLA/PA-WA Composite

Faculty of Mechanical Engineering, Universiti Teknologi MARA, 40450 Shah Alam, Selangor, Malaysia

^* Corresponding author: norhafiez@uitm.edu.my

Abstract

Fused Deposition Modelling (FDM) is a widely adopted 3D printing technology valued for its capability to produce intricate and customizable components with high efficiency. Polylactic Acid (PLA), a biodegradable and cost-effective polymer, is commonly utilized in FDM. However, its mechanical performance and bioactivity remain insufficient for load-bearing biomedical applications such as bone implants. To address these limitations, this study explores the development of a PLA-based composite reinforced with Polyamide 12 (PA12) and Wollastonite (WA), a bioactive mineral filler known to enhance stiffness, strength, wear resistance, and osteoconductivity. Despite the promising potential of this material system, the influence of different printing infill patterns on mechanical performance has not been comprehensively examined. In this study, PLA/PA-WA composites were printed as functionally graded materials (FGMs) using three distinct infill geometries: triangle, grid, and tri-hexagon. All specimens were fabricated under consistent parameters (100 mm/s print speed, 0.1 mm layer height, 200 °C nozzle temperature) and subjected to mechanical testing and density analysis via Archimedes’ Principle,. The tri-hexagon infill demonstrated superior mechanical properties, with a compressive strength of 101.27 MPa and Young’s modulus of 1.48 GPa, and the lowest density error (1.98%), highlighting its suitability for cancellous bone applications. These findings contribute to optimizing 3D-printed biomaterials for sustainable and functional implant development.