Influence of Machine Parameters on the Physical Characteristics of 3D-Printed Sand Molds for Metal Casting

3D sand printing is an emerging technology that is enabling new possibilities in metal casting with respect to part complexity, casting design, and rapid mold production. The 3D printing technology, also known as additive manufacturing, is a binder jetting process which involves selectively depositing a furan-based binder into a sand bed one thin layer at a time. Over the course of the process, layers are subsequently added until the entire part has been fabricated. Although the use of 3D-printed sand molds in the foundry industry is growing, significant hesitation to widespread implementation remains. In this work, an investigation was conducted to determine the influence of machine settings on the physical characteristics of 3D-printed sand. Two factorial matrices were constructed to directly measure the significance of six settings that change the resin content and compaction characteristics of the bonded sand. Factors include: X-resolution, printhead voltage, layer thickness, and the frequency, speed, and angle of the recoater blade. Responses include: density, permeability, strength, scratch hardness, loss on ignition, and print resolution. Several relationships are reported between machine settings and physical properties of the product. These results will help inform mold manufacturing as the foundry industry continues to adopt additive technologies.