Mechanical Properties of Polypropylene: Additive Manufacturing by Multi Jet Fusion Technology

Multi jet fusion (MJF) technology has proven its significance in recent years as this technology has continually increased its market share. Recently, polypropylene (PP) was introduced by Hewlett-Packard for the given technology. To our knowledge, little is known about the mechanical properties of polypropylene processed by MJF technology. During this study, standardised specimens were printed under all of the major orientations of the machine's build space. Each of these orientations were represented by five samples. The specimens then underwent tensile, bending and Charpy impact tests to analyse their mechanical properties. The structural analysis was conducted to determine whether PP powder may be reused within the MJF process. The mechanical tests showed that the orientation of the samples significantly influences their mechanical response and must be carefully chosen to obtain the optimal mechanical properties of PP samples. We further showed that PP powder may be reused as the MJF process does not significantly alter its thermal and structural properties.