Comparison of Different Infill Patterns in Cylindrical PLA Tensile Test Specimens Produced with FDM

Additive manufacturing technologies have become one of the most studied production methods in recent years thanks to their numerous advantages. The technology, which has spread from home and office environments to industry, increasingly using in many sectors. Among these methods, FDM-type 3D printers are the most preferred additive manufacturing method due to their affordability and ease of application. However, because the polymers used in FDM must be thermoplastic, they are available in a smaller range compared to traditional methods. Furthermore, due to their layered structure, the strength properties of these thermoplastics lower compared to methods such as injection molding. Therefore, studies have focused on optimizing printing parameters that directly affect material development and strength. This study examined infill patterns, which play a critical role in printing parameters. Tensile samples with 11 different patterns were produced using FDM, and their stress and strain values were compared. Furthermore, to better visualize the effects of the infill patterns, the tensile samples printed in cylindrical form. Additionally, small cylinders produced, and diameter and height measurements taken, allowing geometric accuracy and shrinkage rates to be calculated. According to the results, the highest stress value was determined in the Grid pattern, and the highest strain value was determined in the Hilbert Curve pattern. It was also noted that samples with spiral-like infill patterns exhibited a different tendency in their tensile behavior. Finally, the greatest volumetric shrinkage calculated in the grid pattern.