Post-process Influence of Infiltration on Binder Jetting Technology

Despite the fast and ongoing advances of Additive Manufacturing processes (AM) in last years, including three-dimensional printing (3DP), models produced by the latter are not as strong as the ones made by other AM technologies. This challenge raises the concern to improve post-processing to create competitive mechanical strengths, which in turn requires specific knowledge that has not focused on applied studies of current plaster-based materials. The aim of this study is to characterize the base material, and to measure the influence of infiltration post processing on flexural and tensile strengths of 3D printed parts. VisiJet® PXL Core was characterized in terms of grain size and chemical composition. Green printed specimens were infiltrated with epoxy resin, cyanoacrylate, magnesium sulphate and water, as recommended by the supplier of equipment and materials for 3DP, and their influence on flexural and tensile strengths was analysed. The increase in flexural strength, up to 450%, in the specimens infiltrated with epoxy resin, relatively to the ones without infiltration (green body), suggests the importance of this post-process. The data obtained by mechanical test were lower regarding the data stipulated by the materials producers. Large standard deviations on mechanical strength, compared with the standard deviation of the green body, are characteristic of the manual processes (brush and drip), suggesting the necessity to establish methodologies to allow homogeneous infiltration and controlled dosages, as well as the use of alternative infiltrates.