Fused pellet modeling (FPM) is an important method in additive manufacturing technology, where granular material is used instead of filaments. In FPM, prototypes are constructed by the sequential deposition of material layers. As the size of the part increases, the problem of long build times and part deformation becomes critical. In this paper, methods for eliminating the void density during deposition and accuracy control principles for large scale FPM processes are studied. By analyzing the ab initio principles of this process, a mini extruder with variable pitch and progressive diameter screw for the large scale fused deposition is proposed. Based on polymer extrusion theory and non-Newtonian fluid properties, each of the design parameters are analyzed, such as the length of different function sections of screw, die shape of extruder nozzle, and the material properties. According to these analysis results, an extrusion process simulation for controlling the filament shape is carried out with multi-physics modeling software and proved the FPM could increase the building efficiency and deposition quality for large size parts.
Z. Wang et al., "A Framework for Large Scale Fused Pellet Modeling (FPM) by an Industry Robot," Proceedings of the 26th Annual International Solid Freeform Fabrication Symposium (2015, Austin, TX), pp. 411-421, University of Texas at Austin, Aug 2015.
26th Annual International Solid Freeform Fabrication Symposium -- An Additive Manufacturing Conference, SFF 2015 (2015: Aug. 10-12, Austin, TX)
Mechanical and Aerospace Engineering
Article - Conference proceedings
12 Aug 2015