Effect of Filler Density on the Mechanical Properties of Natural PEEK 450 Processed by FDM

In the present investigation, the mechanical properties of natural PEEK 450 processed by 1 additive manufacturing and applying fused deposition modeling (FDM) are investigated. Mechanical 2 characterization was performed through destructive testing, following ASTM D638-14, ASTM D695- 3 15 and ASTM D790-10 standards. Specimens were designed in CAD software and printed with 4 controlled infill densities of 40%, 70% and 100%, using a rectilinear pattern. The results showed that 5 an increase in infill density improves mechanical strength and stiffness, but reduces ductility and 6 energy absorption capacity. These findings offer crucial information for optimizing infill density in 7 the manufacturing of high-strength components for industrial and biomedical applications. As a 8 result, practical guidelines are provided for the design of medical devices, such as implants, achieving 9 an appropriate balance between mechanical performance and material efficiency.