Coalescence process of two fluid particles is very complicated. This paper tries to integrate the approaching process of two fluid particles and the draining process of the intervening liquid film between two particles

by using the assumption of plane film and taking into consideration the change of the radius of plane film and the interaction force between two fluid particles with time. Thus

an integrated model for the minimum thickness of the intervening liquid film between two contacting fluid particles is developed.The effects of size ratio

initial relative velocity

interface tension and viscosity of continuous phase on minimum film thickness are discussed based on the integrated model. The comparison between the model calculation and the data from Scheele and Leng shows that this model is reasonable.The Stefan-Reynolds equation is only fit for draining of plane film which has been formed already

so its time coordinate is not identical to that of the contact interaction plane film model.Accordingly a time difference should be allowed for in advance in this model.