Numerical Prediction and Experimental Validation of Deposited Filaments in Direct Ink Writing: Deposition Status and Profile Dimension

The deposition status and profile dimension of deposited filaments have an impact on the quality of the printed parts fabricated by direct ink writing (DIW). Previous works often failed to realize the full quantitative characterizations of the detailed influence of the process parameters on the deposition status and profile dimension. Herein, we predict and analyze the deposition status and profile dimension by proposing an improved three-dimensional (3D) numerical model. The prediction accuracy of the proposed numerical model is verified through filament deposition experiments. The maximum relative errors of width and height between the experimental and simulation results of cross-sections are 10.13% and 7.37%, respectively. The effect of process parameters on the deposition status and profile dimension has been quantified. Critical process parameters are identified as the dimensionless nozzle velocity (V*) and the dimensionless height (H*). Three deposition statuses named over-deposition, pressed deposition and freeform deposition are characterized depending on the combination of V* and H*. The current work demonstrates an effective approach for the prediction of the deposition status and profile dimension of the deposited filaments along with the investigation of the effects of process parameters in DIW based on numerical simulations.