Emulsifying equipment
The main mechanical equipment for preparing emulsion is emulsifying machine, which is a kind of emulsifying equipment for mixing oil and water evenly. At present, there are three main types of emulsifying machine: emulsifying mixer, colloid mill and homogenizer. Emulsifying machine type and structure, performance and the size of the emulsion particles (dispersion) and the quality of the emulsion (stability) has a great relationship. Generally, such as now widely used in cosmetics factory stirring emulsifier, the emulsion produced by the poor dispersion. The particles are large and coarse, with poor stability and easy pollution. But its manufacture is simple, the price is cheap, as long as you pay attention to the reasonable structure of the machine, use properly, but also can produce a general composite quality requirements of the popular cosmetics. Colloid mill and homogenizer are better emulsifying equipment. In recent years, emulsifying machinery has made great progress, such as vacuum emulsifying machine, the emulsion prepared by the dispersion and stability of excellent.
The temperature
The emulsification temperature has a great influence on the emulsification, but there is no strict limit on the temperature. If oil and water are liquid, they can be emulsified by stirring at room temperature. Generally, emulsification temperature depends on the melting point of substances with high melting point in the two phases, and factors such as the type of emulsifier and solubility of oil phase and water phase should be considered. In addition, the temperature of the two phases should be kept nearly the same, especially for the wax and fat phase components with high melting point (above 70℃), when emulsifying, the low temperature water phase should not be added, in order to prevent the wax and fat from crystallizing out before emulsification, resulting in massive or coarse and uneven emulsion. Generally speaking, when emulsifying, the temperature of oil and water can be controlled between 75℃ and 85℃. If the oil phase has high melting point wax and other components, the emulsifying temperature will be higher at this time. In addition, if the viscosity increases greatly in the emulsification process, the so-called too thick and affect the mixing, some emulsification temperature can be appropriately raised. If the emulsifier used has a certain phase transition temperature, the emulsifying temperature is also best chosen around the phase transition temperature. Emulsification temperature sometimes also affects the particle size of the emulsion. If the anionic emulsifier of fatty acid soap is generally used, the particle size of emulsion is about 1.8-2.0μm when the emulsification temperature is controlled at 80℃. If the particle size is about 6μm when the emulsification is carried out at 60℃. The effect of emulsification temperature on particle size is weak when non-ionic emulsifier is used for emulsification.
Emulsifying time
Emulsification time obviously have an impact on the quality of the emulsion, and the determination of emulsifying time is according to the volume ratio of oil phase water phase, two phase viscosity and generate the viscosity of the emulsion, the type and dosage of emulsifier, emulsifying temperature, emulsifying time of how many, is sufficient to make the system of emulsification, is closely linked to the efficiency of emulsification equipment, Emulsification time can be determined according to experience and experiment. Emulsification with homogenizer (3000 RPM) takes only 3-10 minutes.
Mixing speed
Emulsification equipment has a great influence on emulsification, one of which is the influence of stirring speed on emulsification. Moderate stirring speed is to make the oil phase and water phase fully mixed, too low stirring speed, obviously can not achieve the purpose of full mixing, but too high stirring speed, will bring bubbles into the system, so that it becomes a three-phase system, and make the emulsion unstable. Therefore, air must be avoided in mixing, and vacuum emulsifying machine has very superior performance.
Post time: Oct-19-2021