The growth, drainage and breakdown of foams

At the higher gas rates, there is a change in the slope of the foam height versus time plot, though with the exception of a transition region, this relationship remains a linear relationship one. The difference between these slopes can be used to estimate the pressure exerted on the films at the top surface of the foam. Since these bubbles are bursting, this is the critical pressure required to cause film failure within the foam. When compared to the stability of films in single film experiments, those in the foam, not unexpectedly, demonstrate lower stability. This is due to vibrations and other disturbances that are present within flowing foams.