Determinação dos efeitos de preenchimento e perímetros nas propriedades mecânicas de peças impressas em 3D com policarbonato

Abstract

This work investigated the influence of 3D printing (FDM) parameters on the mechanical properties and manufacturing efficiency of Polycarbonate (PC) parts. A full factorial design (3²) was employed, varying infill density (15%, 50%, 100%) and the number of perimeters (2, 3, 4), while keeping extrusion temperature (280 ºC) and Gyroid pattern constant. Specimens manufactured according to ASTM D638 were subjected to tensile testing, and data were evaluated using Analysis of Variance (ANOVA). Results indicated that infill density is the dominant factor for Ultimate Tensile Strength (UTS), with solid parts (100%) reaching a maximum of 43.89 MPa. However, ductility was governed by perimeters; notably, solid parts with thin walls (2 perimeters) exhibited premature brittle failure (4.45% elongation). The configuration of 15% infill with 3 perimeters emerged as the most efficient engineering choice, delivering the highest ductility (6.91%) and competent strength, combined with a 33% reduction in mass and 25% in print time compared to the solid part. It is concluded that for Polycarbonate, static strength is a function of core mass, while toughness depends on shell integrity, requiring specific optimizations for each final application.