3D printing clay extrusion study

Machine was an introductory workshop to introduce technologies, techniques, and materiality on deposition modeling and its implication in the design.

With the setup of a standard form that could return in various shapes, research groups experiment with different parameters of the material itself or the machine. The result is a matrix of primary geometries with different characteristics from which could be extracted machine parameters and setup conclusions.

Viscous enough, it needed to reach its perfect plastic state in order to be extruded – exploration was designed using only clay. The tactile sense was an important decisional factor in creating the ideal paste made of clay powder and water.

Setting up the machine with only the following nozzle diameters (N) ⌀2 / 3 / 4mm led us to define a ratio between them and the slicing distances (Sd) and explore its questionable similarity and applicability in a larger scale prototyping. Thus, for a more optimized conclusion, the sliced geometry was defined by a ratio (Sd/N) of ca. 0.5  / 0.7 / 0.9 / 1.0 for every nozzle diameter available – resulting in various slicing distances, always maintaining the rest of the parameters at the same rates.

Example of printing parameters:

• Feedrate (F mm/s): 1000
• Jog Speed: 4000
• Extruding Speed (E): 5
• Retraction Setting: 0
• Safety Offset: 5
• Pressure (Bar): 2.5

After printing multiple samples, the evaluated 3D printed clay iterations drove to the conclusion that a ratio close to 0.5 is better to achieve the best results in pieces. This conclusion was made considering aesthetics and structural factors such as lesser cracks in the extruded material, or thicker connection between the layers.