Phase-field modeling of liquids splitting between separating surfaces and its application to high-resolution roll-based printing technologies
Dr. Fahri Erinç Hızır
An in-depth understanding of the liquid transport in roll-based printing systems is essential for advancing the roll-based printing technology and enhancing the performance of the printed products.
In this study, phase-field simulations are performed to characterize the liquid transport in rollbased printing systems, and the phase-field method is shown to be an effective tool to simulate the liquid transport. In the phase-field simulations, the liquid transport through the ink transfer rollers is approximated as the stretching and splitting of liquid bridges with pinned or moving contact lines between vertically separating surfaces. First, the effect of the phasefield parameters and the mesh characteristics on the simulation results is examined. The simulation results show that a sharp interface limit is approached as the capillary width decreases while keeping the mobility proportional to the capillary width squared. Close to the sharp interface limit, the mobility changes over a specified range are observed to have no significant influence on the simulation results.
Next, the ink transfer from the cells on the surface of an ink-metering roller to the surface of stamp features is simulated. Under negligible inertial effects and in the absence of gravity, the amount of liquid ink transferred from an axisymmetric cell with low surface wettability to a stamp with high surface wettability is found to increase as the cell sidewall steepness and the cell surface wettability decrease and the stamp surface wettability and the capillary number increase.
Strategies for improving the resolution and quality of roll-based printing are derived based on an analysis of the simulation results. The application of novel materials that contain cells with irregular surface topography to stamp inking in high-resolution roll-based printing is assessed.
Dr. Fahri Erinc HIZIR received PhD and MS degrees from the Massachusetts Institute of Technology (MIT) and an MS degree from the Pennsylvania State University (PSU), all in mechanical engineering. His research interests include liquid ink transport in roll-based printing systems; metamaterial-based acoustic imaging; and water management in fuel cells. He conducted research in the Laboratory for Manufacturing and Productivity (MIT); Nanophotonics and 3D Nano-manufacturing Laboratory (MIT); and Fuel Cell Dynamics and Diagnostics Laboratory (PSU).