Extruder Design in Pellets Operated 3D Printers: A Review

The pellets/granulate/flakes operated 3D printer is a novel layer by layer part fabrication technique based on the extrusion of the pellets particles using the mechanism of screw extrusion and positioning system. When the mechanism of the screw extrusion has been complete in a single stage, the single screw design could be included to form a group of pellets operated 3D printers. Similarly, in the case of a double-stage screw extrusion system, two screws 3D printers could be used with a relatively large diameter for the first stage screw. The hopper, screw, heating system, temperature sensor, barrel, nozzle, and positioning system are the most common elements in the design of pellets operated 3D printers. Materials with high flexibility will have great potential as pellets operated 3D printer materials. In this paper, a single-stage screw extrusion, double-stage screw extrusion, flexible, and non-flexible material extruder designs for pellets operated 3D printers have been studied. Apart from this, the process parameter behaviour of the pellets operated 3D printers has also been studied. Literature showed that the based on the variation in the extruder design number of the process parameters varies. The number of the elements in the design of the extruder responsible for the overall build volume or size of the machine which greatly varied when compared with the conventional 3D printers. This effect may lead to an increase in resistance to large part fabrication, and thus increase the portability resistance of the pellets operated 3D printers.