The Fuse Filament Fabrication (FFF) technology is evolving in terms of processable materials, print resolution, build volume, and print quality. However, the existence of many processing parameters, each having a wide range of operable limits, makes FFF a process that is often subjected to trial-and-error, which has led to 3D-printed parts with poor quality and inconsistent results. Additionally, it is difficult to predict the FFF thermoforming process using conventional theories and models developed for traditional thermoforming processes. This has created a huge drawback for the adoption of FFF as a mainstream manufacturing process due to the lack of in-depth theoretical understanding and the potential disconnect between material and process aspects. To bridge this gap, a holistic analysis of the rheological properties of the entangled viscoelastic polymer melts and the complex multiphysics associated with the process using theoretical and computational models is required. Hence this presentation covers four aspects (1) Investigation of the rheological properties of polymer melt to identify bounds on viscosity. (2) Investigation of thermal evolution and fluid flow in the hot-end of a material extrusion 3D Printer using a melting model. (3) Applying the enthalpy-porosity method to model the complex flow through the hot-end in material extrusion additive manufacturing. (4) Model the effect of nozzle diameter and heat flux on the polymer flow in FFF. The presented model suggests that improving the understanding of the complex flow physics in the hot-end for melting polymers can assist in faster and closed dimensional tolerance of the printing parts, redesigning of the hot-end, inline process parameter monitoring, and control. This work facilitates Computational/Design for Additive Manufacturing (CDAM & DfAM), impacting, directly and indirectly, FFF-related industries e.g., healthcare, automotive, and aerospace.
Learning Objectives:
- Upon completion, participants will be able to list all process parameters that constitute the printability of material using fuse filament fabrication additive manufacturing.
- Upon completion, participants will be able to define and formulate the constitutive physics- based models required to model the complex flow through the hot-end in material extrusion additive manufacturing.
- Upon completion, participants will be able to describe and correlate the rheological properties of the entangled viscoelastic polymer melts and the complex multiphysics associated with the process using computational models.
