The force required to pull two plates apart with liquid in between, at zero contact angle, depends on the speed of separation. For slow separation, the Laplace Young equation can be used to derive the force based on the curvature of the liquid bridge and the pressure difference. In contrast, for rapid separation, the situation is modeled as a squeeze film, requiring solutions from the Navier-Stokes equations and considering axi-symmetry. The capillary number plays a crucial role in determining the separation speed and the corresponding force calculations. Understanding these dynamics is essential for accurately predicting the force needed to separate the plates.
