Ascertaining Life Cycle Inventory Data for Electrical Discharge Machining

Sustainable manufacturing systems require accounting for both product and process level environmental impacts. Established methods and databases are available for product level environmental impact assessment. However, there is a lack of data for process level or use phase assessments despite these being responsible for a significant share of the total environmental impact. This lack of data is even further exacerbated for unconventional machining (UCM) - unit process Life Cycle Inventory (LCI) data for UCM processes has particularly limited records in LCI databases. Electrical discharge machining (EDM), which is the most widely used UCM process, is reported as much less energy efficient compared to conventional machining processes. In addition to that, EDM produces wastes in solid, liquid, gas and aerosol form increasing its environmental footprint. The purpose of this study is to ascertain LCI data for EDM processes and thus to facilitate improved life cycle assessment during the use phase. The study takes insights of CO2PE!-methodology, a systematic inventory analysis of the use phase of manufacturing unit processes. Case studies are carried out with an industrial die and mould manufacturer. The resultant data for die sinking and wire EDM is then compared with publicly available data. Challenges of generalising LCI data are discussed with future improvement potentials.