Withdrawal and dip coating of an object from a yield-stress reservoir, Wilbert J. Smit, Christophe Kusina, Annie Colin, and Jean-François Joanny Phys. Rev. Fluids 6, 063302 (2021)

Withdrawal and dip coating of an object from a yield-stress reservoir, Wilbert J. Smit, Christophe Kusina, Annie Colin, and Jean-François Joanny Phys. Rev. Fluids 6, 063302 (2021)

https://journals.aps.org/prfluids/abstract/10.1103/PhysRevFluids.6.063302

Résumé :

The dip-coating process consists of withdrawing immersed objects from a liquid reservoir. After withdrawal, a significant layer of liquid remains on the object. Various industrial processes (food and beverage industry, automotive industry) use this technique to coat or treat surfaces. Recent studies have shown that the thickness of deposit is determined by the flow inside the reservoir for yield-stress fluids. This is different from the behavior of simple liquids for which the coating thickness is solely determined by the flow inside the meniscus. In this work, we reexamine this question and propose a complete phase diagram linking the Newtonian case and the yield-stress fluid case. We provide asymptotic scaling laws for extreme cases. A good agreement with experiments is obtained.