Design and development of solid particle ejector for an FDM 3D printer

Abstract

Fused deposition modelling (FDM) printed polymeric parts are weaker compared to injection moulded counterparts.  Reinforcing polymers with additional materials during 3D printing is one of the possible methods to improve the mechanical properties of FDM printed polymers. In this study, an innovative ejector for short fibres was developed that can be connected to existing FDM 3D printers. The additional ejector is capable of depositing short fibres during printing to produce short fibre reinforced thermoplastic (SFRT) composites. The main advantage of this ejector is that it can be mounted on the commercial FDM 3D printers and the existing thermoplastic extruder does not need to be modified. A prototype of the ejector was built and tested. The fibre deposition rate of the ejector was tested and compared to the designed specifications. The results of prototype testing show that the fibre deposition rate is consistent with the designed value. Along the way, there are some challenges such as ejector reliability and deposition rate. These challenges will be discussed in detail.