Effects of used sand recycling on the foundry properties of three-dimensional printed sand moulds and cores

Sand casting is one of the important metal casting processes that involves hard labour and patternmaking to produce sand moulds. However, it has evolved considerably since the adoption of rapid sand casting, a type of additive manufacturing. This advancement has reduced costs and improved lead time by eliminating tooling. Nevertheless, there are still some challenges that are being experienced, such as the recyclability of the waste sand produced by the foundry. With high costs of virgin sand and sand disposal, reusing the used sand is important. The objective of this paper is to evaluate the feasibility of adding new sand to the used sand during rapid sand casting. The results indicate that the semi-activated sand collected from the hopper can be reused to produce sand moulds and cores if new sand is added to it.