Definition
A dispersion emulsifier is a mechanical equipment used to mix, disperse, and form a stable milky liquid between two or more immiscible liquids, such as oil and water. In laboratory and industrial processes, it is used to emulsify, homogenize, or disperse by applying high shear forces to evenly disperse one phase in the form of tiny droplets in the other. The equipment has a wide range of applications in many non-medical fields such as food, cosmetics, chemical industry, materials science and environmental testing.
Principle
The core working principle of the dispersion emulsifier is based on mechanical shearing. The equipment is usually composed of a rotor and stator rotating at high speed, when the rotor runs at high speed in the stator, the material is sucked into the working cavity, and in the narrow gap between the rotor and the stator, it is subjected to strong shear, impact and turbulence. This high shear force is able to break up particles or droplets in a liquid, reducing their size and dispersing them evenly in the continuous phase. The emulsification process can be described as a dynamic equilibrium between droplet breakage and reaggregation, and the stability of the final emulsion depends on the energy input provided by the equipment and the interfacial properties of the system itself.
Measurement and evaluation methods
The evaluation of the dispersion emulsification effect is usually achieved by measuring the particle size distribution, stability and rheological characteristics of the emulsion. Particle size analysis can be done by laser diffraction or dynamic light scattering, and its distribution width can reflect the uniformity of emulsification. Stability can be assessed by centrifugation acceleration experiments or by long-term standing observation of stratification. In addition, viscosity measurements can be used to characterize the rheological behavior of emulsion systems. These parameters can be measured according to relevant industry standards such as ISO, ASTM or national standards to provide a basis for process optimization.
Influencing factors
The dispersion emulsification effect is affected by a variety of factors. Equipment parameters include rotor speed, stator and rotor clearance design, processing time, and operating temperature control. Process conditions such as feed speed, material ratio and emulsification times also affect the final result. In terms of material properties, the viscosity ratio, interfacial tension, and emulsifier selection and concentration of the two phases play a key role in the size and stability of the droplets. In actual operation, these factors need to be comprehensively adjusted according to the characteristics of the material and the requirements of the target product.
Applications
In the food industry, dispersion emulsifiers are used in the production of sauces, dairy products, and beverages to optimize taste and texture. The cosmetics sector relies on it to prepare creams, lotions, and other products to ensure uniformity and stability in ingredients. In the chemical industry, it is used for the dispersion process of synthetic resins, coatings, and inks. In materials science laboratories, the preparation of nanomaterials or composites often requires high shear emulsification to achieve uniform dispersion. In terms of environmental testing, it can be used to prepare standard samples or emulsify water treatment reagents.
Selection considerations
When choosing a dispersion emulsifier, it is necessary to comprehensively consider the physical and chemical properties, target particle size range, processing volume and process requirements of the treated materials. Laboratory-scale equipment should focus on operational flexibility and parameter controllability, such as speed range, temperature control capabilities, and easy-to-clean design. Industrial models need to focus on capacity, energy consumption and durability. In addition, the equipment material must be compatible with the material to avoid corrosion or contamination. It is recommended to refer to the technical requirements of emulsification equipment in relevant industry standards and make a choice based on the actual process test results.