Dynamic effect of surface contact angle on liquid transfer in a low speed printing process

In this study, experiments on liquid transfer were performed to observe the change of the surface contact angle with respect to the process speed. The liquid transfer ratio from the experiments was compared with that from numerical simulation for low speed ranges. While the surface contact angle on the lower plate was almost constant in the experiment regardless of operating speed, the surface contact angle on the upper plate was found to be significantly changed during the process at the low speed ranges. This resulted in a reduction of the transfer ratio. By applying the time-dependent values of contact angle to the numerical simulation model, the transfer ratio showed better agreement with the experimental results. The dynamic effect of surface contact angle should be considered as an additional variable, especially for the analysis of liquid transfer in a low speed printing process. (C) 2014 The Japan Society of Applied Physics