Investigation of Process Induced Variations in PolyJet Printing with Digital Polypropylene via Homogeneous Tensile Test Coupon

The capability of additive manufacturing (AM) of making the monolithic, multi-material structure allow the fabrication of complex parts with varying mechanical properties. Many AM processes and equipment utilize proprietary material stocks from equipment vendors. A better understanding of the digital material mixing behavior to form traditional material configurations during AM is critical.Many jetting based AM processes also has the capability to print different material gradient and build them layer by layer in specific concentration of two or more base materials. This paper investigates the tensile strength and mechanical behavior of these digital materials formed by mixing or multi-material interfaces fabricated by material jetting. Further, due to flexibility of orientating the digital design in AM, a part can be created in any orientation; however, processing-induced variation affects the performance of parts, as the way AM forms part is different from traditional manufacturing that leads to many artifacts. These artifacts affect the mechanical properties and behavior of final parts formed in AM. To eliminate the process induced effect that are exit in traditional 2D test coupon, this paper evaluates a homogenized 3D configuration test coupon which reduce the geometric effects in AM, that we had recently proposed and investigated.