Emulsifying is the process of mixing two liquids that are difficult to mix. The main focus of emulsifying is the dispersion of the discontinuous phase into preferably fine droplets. Rotor-stator machines are particularly well-suited for emulsifying tasks. The combination of high shearing and expanding forces in the mixing head allows for very fine droplets. High turbulences also enable rotor-stator machines to contribute to a quick transport of emulsifier molecules to the newly-formed surfaces.
Numerous medical ointments, cosmetic products, milk, mayonnaise, and dressings are emulsions. The emulsifying process can be visualized by looking at mixing water with oil, or fat. How do you mix oil and water? Even after intensive stirring for a long period of time, the oil swims at the water’s surface once again. The energy input is important here, but also the employed technology, the emulsifying.
Emulsions are usually stabilized by emulsifiers such as tensides, which are mixed into one of the two phases before emulsifying. Emulsifiers are one part water-loving (hydrophilic) and one part fat-loving (lipophilic). One side of the emulsifier molecule bonds with the water and the other one with the oil. In this manner, emulsifiers stabilize the produced droplets and therefore counteract a segregation of the emulsion.