Inkjet printing of polyvinyl alcohol multilayers for additive manufacturing applications

Here we demonstrate that inkjet printing technology is capable of producing polyvinyl alcohol (PVOH) multilayer structures. PVOH water-based inks were formulated with the addition of additives such as humectant and pigments. The intrinsic properties of the inks, such as surface tension, rheological behavior, pH, wetting, and time stability were investigated. The ink's surface tension was in the range 30–40 mN/m. All formulated inks displayed a pseudoplastic (non-Newtonian shear thinning and thixotropic) behavior at low-shear rates and a Newtonian behavior at high-shear rates; were neutral solutions (pH7) and demonstrated a good time stability. A proprietary 3D inkjet printing system was utilized to print polymer multilayer structures. The morphology, surface profile, and the thickness uniformity of inkjet printed multilayers were evaluated by optical microscopy and FT-IR microscopy