Analysis of ink transfer process for R2R printing applications with non-Newtonian ink property

FSI occurring in the ink transfer process from the printing roll to the moving web was investigated using a CFD technique for the application in R2R printed electronics. Analysis for the flow-structure interaction was conducted to assess the deflection and stress distributions of the web. In order to make the present analysis more realistic, the metallic ink was idealized by a non-Newtonian fluid and, the numerical geometry and the ink properties were selected to match those of the real printing production system. Our numerical results showed that both web handling speed and non-Newtonian assumption significantly influenced the shape of the transferred ink. As the web moving speed increased beyond 5m/min, a significant distortion of the transferred ink shape occurred. Also, non-negligible web deflection occurs in all the geometries considered in the present work but the ratio of the web deflection to the line width gets smaller as the web handling speed becomes higher.