Liquid transfer in gravure printing processes: A new numerical approach to study the effect of cavity shape

DIEGO MARTIN CAMPANA; MARCIO S. CARVALHO

Atlanta, Georgia

Simposio; 16th International Society of Coating Science and Technology Symposium; 2012

International Society of Coating Science and Technology

Industrial printing processes, such as gravure and flexography have gained great attention in last years because of its potential applicability to the fabrication of polymeric solar cells and other flexible electronic devices, which are basically printed on a flexible substrate. Dodds et al. (2009) have used a 2D-axisymmetric numerical model to study the liquid transfer from a cavity full of liquid to a flat moving plate. The model supposes a liquid bridge formed between both the cavity and the plate, which eventually brakes when the plate is moving away from the cavity at constant velocity (only under extension). They did a careful parametric study to investigate the effect of wettability, capillary number, cavity shape and other parameters on the fraction of liquid  transferred from the cavity to the plate. The results show that the amount of liquid transfer is primary controlled by the cell shape and surface properties, being extremely important the pinning experienced by the contact line on the cavity wall. Although they suggested a cavity with steeper wall and sharp corners could promote more severe pinning effect, no results were included to support this suggestion. In this work we present a new numerical technique that overcomes some limitations of the previous one and new results that are in agreement with the aforementioned sugestions.