ADDITIVE MANUFACTURING FOR INVESTMENT CASTING: ECONOMIC COMPARISON BETWEEN DIGITAL LIGHT PROCESSING AND WAX MOULDING

Additive manufacturing (AM) is rapidly gaining popularity and is used to create finished goods or moulds (rapid tooling). AM is also frequently employed for generating patterns and moulds, often in conjunction with casting to produce massive metal components to overcome the drawbacks of casting techniques. Compared to wax injection, Rapid Investment Casting (RIC), which is the application of AM in Investment Casting, may guarantee a significant reduction in lead time. Given the innovative nature of this technology, the scientific literature lacks in providing techno-economic evaluations concerning adopting Digital Light Processing (DLP) technologies for RIC. This study examines the techno-economic implications of using additive manufacturing (i.e., DLP) to create wax or resin models. The article provides a decision-making tool to help stakeholders assess AM’s benefits for manufacturing wax patterns instead of wax injection. Analytical cost models are provided for estimating the manufacturing time and cost of the compared technologies. The study considered two production scenarios distinguished by the machine load factor for DLP (10% and 50%). Mainly, the technology comparisons are based on production costs and times. The study takes into account parts from the fashion and mechanical sectors. Results indicate that AM is faster and cheaper than injection moulding for production batches up to 10E2 (as an order of magnitude) for small-size components and 10E1 for large parts. This outcome derives from the avoided cost for the moulds required for the injection process. Regarding cost and time, the batch cross-over points decrease when the dimensions of components are increased.