A Modelling-Based Framework for Carbon Emissions Calculation in Additive Manufacturing: A Stereolithography Case Study

Manufacturing is one of the most heavily contributing sectors to global warming via its high carbon emissions. Initiatives such as the Green Deal and Sustainable Goals by the United Nations are supporting the reduction of carbon emissions in the manufacturing sector, which can be completed by making manufacturing processes more sustainable and with less carbon footprint. This also applies to novel manufacturing processes such as additive manufacturing (AM). In this work, a previously developed framework for carbon footprint calculation was tailor-made and applied to a specific stereolithography (SLA) case. The different steps of the SLA were categorised per process, machine tool and system level, and the respective carbon emissions were calculated, either theoretically or via a life cycle assessment software. The carbon emissions at the process level were significant when compared to the total carbon emissions, and the carbon emissions of the isopropanol (IPA) bath accounted for more than 50% of the total carbon footprint of the SLA. These results demonstrate that the AM process may not be as environmentally friendly as it was assumed to be, especially if post-processing and finishing steps are carbon-intensive, because of the liquids used for the baths.