Plate-out modelling for cold-rolling systems lubricated with oil-in-water emulsions

Oil-in-water (O/W) emulsions are widely used for steel-rolling processes. An efficient lubrication is required to control the oil film deposition on the strip surface. This article deals with phase separation in lubrication film formation before roll bite (plate-out). A model has been developed to simulate the behaviour of an emulsion droplet that impacts onto a moving plate. The typical configuration of emulsion droplet impact is considered in a calculation which controls the initial formation of the film. To describe hydrodynamic phenomena, wetting and three-phase contact line models have been integrated in a Navier-Stokes-based computational fluid dynamic code. Both models have been validated against data from the literature. Numerical studies carried out with the model have highlighted the importance of the oil concentration in the droplet on the plate-out occurrence. A ballistic study has also been performed to evaluate the influence of the droplet velocity on the film formation.