Material Property Testing of 3D-Printed Specimen in PLA on an Entry-Level 3D Printer

An entry level consumer priced 3d-printer, the MakerBot Replicator 2x, was used to print specimen to conduct tensile, flexural and fatigue testing. Average priced, generic brand PLA material was used (similar to the filament a home user may purchase). Specimen were printed at raster orientation angles of 0°, 45° and 90° to test orientation effects on part strength. PLA filament was also tensile tested. Tensile testing of the 3d-printed specimens showed that the 45° raster orientation angle made the strongest specimen at an ultimate tensile strength of 64 MPa. The 0° and 90° raster orientation were not much less at 58 MPa and 54 MPa. A 3-point bending fixture was used to conduct flexural testing on printed specimen. For this type of testing, the 0° raster orientation produced the strongest parts with an ultimate bending stress of 102 MPa. Both the 45° and 90° raster orientations had similar results at 90 MPa and 86 MPa. For the fatigue testing, there was no clear best option, but there was a clearly worst option, the 90° raster orientation. This orientation clearly had lower fatigue lives than either of the other two raster orientations. The other two raster orientations, 0° and 45°, were very similar. PLA filament testing using bollard style grips, showed that the PLA filament exhibited mechanical properties similar to that of printed specimen — when tested at high enough strain rates that creep damage didn’t play a significant role. This may lead to implications for recycling failed 3d-print jobs and turning it back into reusable filament.