Dip coating is the immersion of a substrate into a tank containing coating material, removing the piece from the tank, and allowing it to drain. Transient coating problems such as this can be solved simply and efficiently using FLOW-3D because the motion of fluid within a stationary mesh is determined (not the motion of a fluid following mesh).
This 3D simulation shows a dip coating process with concomitant evaporation. A wet film is deposited by withdrawal of a small discrete substrate from a solution. The model additionally accounts for the evaporation of the solvent. This is relevant in the case of volatile solvent, for which evaporation overlaps with fluid mechanics during film deposition. The residue model provides the unique capability to calculate the profile of the coated dry film. The correct evaluation of the “edge effects” allows engineers to analyze the influence of process parameters or fluid properties on the final thin film geometry and homogeneity. Modeling courtesy of Roche Diagnostics.