Applications of three-dimensional printing (3DP) to sand casting have been well-established in the last two decades. The preferred raw material is silica (quartz) sand, as it is the most readily available and cost effective sand. However, silica sand as a refractory material has some technical limitations, including high thermal linear expansion, low refractoriness, and thermal conductivity. Therefore, it is not suitable for all castings. Other refractory sand types are available, including chromite sand, which is abundantly available in South Africa. Analysis of the physical and chemical properties of in-laboratory coating of a locally available chromite sand was conducted through known metal foundry tests that provide an understanding of the quality and suitability of the use of chromite sand as a potential substitute for silica material for rapid sand-casting applications. The results of this study will inform the industry about the optimisation of parameters for the manufacturing of a resin-coated chromite sand and its use in additive manufacturing using a Voxeljet VX 1000 printer.

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This paper compares two commercial acid-cured furfuryl alcohol resins. The first material is used for conventional sand moulding (CSM), while the second material was manufactured for the binder jetting process (BJP) using a Voxeljet VX 1000 printer. To that end, chromite sand test specimens were prepared following the American Foundry Society (AFS) procedures to assess various foundry properties, including flowability and flexural strength. The study provides valuable insight into furan resins' properties and differences. In addition, the investigation provides an understanding of the requirements for a suitable local furfuryl alcohol resin for the binder jetting process to produce quality three dimensional printed sand parts.

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