The Effect of Infill Angle and Build Orientation on the Impact Strength and Production Time of Porous Infill Structure

In developing a lightweight structure, the density of the structure can be reduced by converting a solid structure to a porous infill structure. Previous research has investigated that a triangular infill structure has the highest impact strength compared to other infill patterns. However, the impact strength of this structure may still be improved by adjusting other parameters without extending the production time. This research goal is to investigate the effect of the build orientation and infill angle on the impact strength and the production time of the triangular infill structure. To achieve that goal, this research uses a 3D printing process to manufacture a triangular infill structure made of Polylactic Acid. Seven levels of infill angle and two levels of build orientation are used to find the effect. In this experiment, twenty-six Charpy Impact specimens are printed using the Fused Deposition Modelling machine. Each specimen is printed according to ISO 179 standards and tested using a GT-7045 impact testing machine to measure the impact strength of the specimen. The results of this experiment indicate that the resistance of the on-edge build orientation to the impact load is better than the flat build orientation. The on-edge build orientation type requires less printing time compared to the flat build orientation type for each infill angle. The use of a 45-degree infill angle exhibits the highest impact resistance. To achieve the shortest printing time, the 0-degree infill angle is recommended.