Effect of Counter-Gravity 3D Printing on PLA Interlayer Fracture Energy

The multiaxial 3D printing process can reduce the manufacturing time and open the new way for the production of graded materials. It will also expand the application of sustainable additive manufacturing for repair and retrofit purposes. In this study, the effect of counter-gravity deposition on interlayer fracture energy of extruded PLA material was investigated. The rectangular samples with one-layer thickness were 3D printed at three orientations of 0°, 90°, and 180° with respect to the direction of gravity force. The samples were subjected to tensile loading perpendicular to the interlayer areas, and the fracture energy was obtained from the calculation of the area under force–displacement curves. The effect of the nozzle orifice diameter on fracture energy was assessed in conjunction with the deposition orientation. The ratio of nozzle orifice diameter to deposition height was 1 for all samples that were made with different nozzle diameters of 0.6 and 0.8 mm. The interlayer fracture type was observed for all samples. For both nozzle diameters, the statistical analysis of the interlayer fracture energies showed no significant difference for the samples that were 3D printed at different orientations.