3D Printing of Rheologically Complex Materials Through Extrusion Processes

This project aims to enhance the quality of 3D-printed objects by investigating the fluid dynamics of non-Newtonian fluids during the printing process. The properties of these fluids change throughout the printing process due to their transient non-linear rheology.
By studying the properties of these materials, yield stress, thixotropy, and shear thinning behaviour, we aim to improve the quality of printed objects.
For example, a paste with high-yield stress will prevent dripping from the nozzle and allow for the construction of tall objects before slumping occurs. Shear thinning behaviour enables the material to be extruded more efficiently, while thixotropy helps the material quickly regain high viscosity, preventing immediate slumping and maintaining its shape.
This project will integrate theoretical models of constitutive laws into the open-source software OpenFOAM to simulate the flow. Initially, the simulations will be implemented in 2D to study how the complex fluid is extruded from the nozzle. The study will then extend to 3D simulations to model the slumping effects of the material. A detailed understanding of material rheology will allow for the development of material-specific protocols to achieve higher-quality final products.