Effects of Nozzle Geometries on 3D Printing of Clay Constructs: Quantifying Contour Deviation and Mechanical Properties

In this research, ready-to-print clay was employed to 3D print cylindrical constructs using two different nozzle geometries. The cylinders were printed using a direct ink writing (DIW) 3D printer with similar printing parameters such that the impacts of using different nozzle geometries in contour deviation and mechanical properties of the printed constructs can be quantified. Choosing the right nozzle geometry before printing is critical as it affects the surface finish as well as the mechanical properties of the constructs. This study utilizes point cloud data of the printed samples obtained from a scanning system to measure the contour deviation and surface roughness. According to the results from the point cloud analysis, for cylindrical constructs, circular nozzle imparts less surface roughness and contour deviation whereas square nozzle imparts higher compression strength but with comparatively higher contour deviation and surface roughness. The study provides framework to determine the deviations and mechanical properties of the free form constructs. The work has provided a guideline of nozzle selection in 3D printing of clay constructs for civil infrastructures.