Mechanical and antibacterial properties of FDM additively manufactured PLA parts

• Published in: Results in engineering 2024-03, Vol.21, p.101744, Article 101744
• Main Authors: Nyabadza, Anesu, Mc Donough, Louis Michael, Manikandan, Arul, Ray, Abhishek Basu, Plouze, Anouk, Muilwijk, Corné, Freeland, Brian, Vazquez, Mercedes, Brabazon, Dermot
• Format: Article
• Language: English
• Subjects: Additive manufacturing; Antibacterial copper nanoparticles; E.coli; Fused deposition modelling; Laser ablation in liquid; Polylactic acid
• ISSN: 2590-1230; 2590-1230
• DOI: 10.1016/j.rineng.2023.101744

This study explores the compression and antibacterial properties of 10x10 × 10 mm polylactic acid (PLA) cubes manufactured through FDM additive printing for biomedical parts. A 3x3 full factorial DOE with 3 replicates examines the impact of printing parameters (infill %, print speed, and layer height). The highest compression strength and stiffness recorded were 91 MPa and 0.76 GPa, respectively. Despite minor mass variations (1.05 ± 0.09 g) under all the investigated parameters, the mean strength of all printed parts was 67.6 ± 10.6 MPa, highlighting the significant influence of processing parameters on mechanical properties. Heat treatment at 60 °C for 30 min improved stiffness. Investigation of various parameters, including layer height and orientation, revealed that larger layer heights resulted in reduced compression strength. Anisotropic compression properties persisted post-heat treatment due to thermal stresses and interlayer bonding. The flat direction (top view) exhibited higher compression properties due to a homogeneous microstructure, minimized interlayer bonding impact, and increased crystallinity. Antibacterial properties against E.coli were induced via coating with peanut-shaped copper nanoparticles (68–267 nm). Nanoparticles were fabricated via a combination of wet chemistry and laser ablation. •Printed PLA parts are anisotropic, flat direction is best for compression.•Novel approach for producing antibacterial Cu nanoparticles combining wet chemistry and laser ablation.•Cu nanoparticle-coated PLA parts for biomedical applications.