Analysis of the Influence of the Exit Geometry and Nozzle Orientation on the Strand Quality When Depositing Curves and Layers in the FLM Process

The aim of this paper is to investigate the effects of different nozzle exit geometries in the FLM process on the deposition of curves and the interconnection of multiple lanes. To investigate the effects of the different nozzle exit geometries, curves were printed with different nozzles, as well as compounds of lanes next and on top of each other. Three unusual exit geometries, triangle, square and hexagon, were compared with the usual circular nozzle shape. Furthermore, the effects of a rotating nozzle were investigated when printing the curved lanes. The results show that the hexagonal exit geometry is the only exit geometry that produces an almost constant profile contour independent of orientation, which strongly resembles the profile contour produced with a circular exit geometry. Both, the triangular and the square exit geometry, exhibit strongly differing profile contours, due to the orientation during the curved deposition process. The evaluation of the multilayer specimens underlines the influence of the exit geometries on the contact areas, void sizes, and the distortion of the profiles.