A framework to reduce product environmental impact through design optimization for additive manufacturing

Abstract

Additive Manufacturing (AM) also known as 3D printing technology has drawn increasing attention from the industrial world. It provides the capability of freeform fabrication to achieve high complexity as well as significant reduction of a supply chain which further enhances the profit margin for manufacturers. However, while claiming on the advantage on the environmental aspect, there is very limited research on the environmental impact of AM technologies. Most of existing environmental assessment models for AM processes are developed based on a general Life Cycle Assessment (LCA) framework. Due to the limited scope and boundary of these models, design results are usually taken as the input. These existing models may work well for traditional manufacturing processes. However, when it comes to AM process, these methods are no longer valid, since the design freedoms which may have a great impact on sustainability are always neglected. To deal with this issue, a general framework which can integrate a design stage in LCA for minimizing the product environmental impact of AM process in particular for binder-jetting process is proposed. The detailed description of each major stage of the proposed framework is presented. This framework has been applied to evaluate the environmental impact of fabricating an engine bracket by binder-jetting process. In this case study, a comparison of environmental impact between CNC and binder-jetting fabrication process is made. The result shows that binder-jetting consumes significantly less energy and produce less CO2 to produce a topologically optimized part than CNC milling for the same product. This case study demonstrates a key role of design optimization in the proposed framework. This proposed framework can be further modified for other typical AM process in the future.