3D Printing under High Ambient Pressures and Improvement of Mechanical Properties of Printed Parts

Contrary to other polymer processing methods, additive manufacturing processes do not require any pressure during the consolidation of layers. This study investigates the effect of high ambient pressure on the consolidation of layers during the FDM process and their analysis of mechanical properties. An experimental setup was arranged, consisting of a 3D printer integrated into a customized Autoclave, to achieve high strength properties for 3D printed parts as like injection-molded specimens. The autoclave can maintain 135 bar of pressure and a maximum temperature of 185 degrees C. 3D printing with PLA was carried out at 0 bar, 5 bar, and 10 bar. Tensile, flexural, and Charpy tests were conducted on printed specimens, and the effect of pressure and temperature on 3D-printed samples were analyzed. It could be shown that autoclave preheating before printing and autoclave pressure during printing improves the consolidation of layers immensely. The pressure inside the autoclave provokes a more intimate contact between the layer surfaces and results in higher mechanical properties such as yield strength, Young's modulus, and impact strength. The properties could be raised 100%.