Energy consumption analysis for additive manufacturing processes

Additive manufacturing (AM) is defined as the process of joining materials to make objects from 3D model data, usually layer upon layer, in contrast to subtractive or forming manufacturing methodologies. In studies of energy consumption in AM systems reported in the literature, the electric energy consumed by different technologies was measured directly in the main electrical supply wires of the machines, which does not represent the process energy consumption, because there are peripheral devices that do not have an influence on the process. In order to generate a better approach to the energy consumption of the AM process, this paper presents a proposal to measure the energy consumption directly in the system stage in which the AM processes are performed: preparing the material for extrusion, deposition, selection, gluing, curing, and so on, obtaining the geometry of a layer defined by an area with a certain thickness, and carrying out bonding between the layers to form a solid part. Because the combination of material and manufacturing processes determine the mechanical properties of a built part and because different materials and processes could be used to obtain these mechanical properties with different energy consumption values, the authors suggest mathematical models for three AM processes (material extrusion, vat photopolymerization, and material jetting) which predict the energy consumption and then compare the values with their experimental results, obtaining a difference of less than 10%, and find the parameters which define the differences in energy consumption among the processes.