Definition
The laboratory multi-function stirring and dispersing machine is a kind of laboratory equipment that integrates various functions such as stirring, dispersing, homogenizing, and emulsification. It treats liquids, slurries, or solid-liquid mixtures through mechanical action to achieve material mixing, particle refinement, system homogenization, and other purposes. The equipment is widely used in sample preparation and process research in many fields such as chemical, food, coatings, new energy materials, cosmetics, and scientific research and education.
Principle
The working principle of the laboratory multi-function mixer disperser is mainly based on the mechanical force and hydrodynamic effect generated by high-speed rotation. The core component of the equipment is a motor-driven mixing shaft at the end of which can be fitted with different types of mixing paddles or dispersion discs as needed. When the motor drives the stirring shaft to rotate at high speed, the dispersion disc or paddle transmits mechanical energy to the material, generating strong shear force, impact force and turbulence. In the shear area, the material is subjected to high-speed relative motion, and larger particles or droplets are torn and broken, so as to achieve dispersion and homogeneity. For high-viscosity materials, the equipment usually adopts a stator-rotor structure, and the material is subjected to high-frequency shear as it passes through a narrow gap, further enhancing the dispersion effect. Its basic power transfer relationship can be expressed as:
P = K ρ N³ D⁵
where P is the stirring power, K is the power accuracy, ρ is the fluid density, N is the stirring speed, and D is the diameter of the agitator. This formula reflects the impact of device parameters on processing power.
Measurement and evaluation methods
The evaluation of the dispersion effect of agitation often relies on the measurement of a range of physicochemical parameters. Common measurement methods include particle size analysis, which uses laser diffraction or dynamic light scattering techniques to determine the particle size distribution of treated samples, and characterizes the dispersion fineness with D50 or D90 values. For emulsion systems, the shape and size of droplets can be observed under a microscope or their stability over time can be measured. For viscosity measurement, a rotating viscometer is used to investigate the change of rheological properties of the material after treatment. In addition, mixing and dispersion effects can be indirectly evaluated by measuring the optical clarity, conductivity uniformity, or consistency of specific component concentrations of samples. During operation, the time and energy consumption required to achieve the target dispersion are often recorded as a reference for process efficiency.
Influencing factors
The stirring and dispersion effect is affected by multiple factors. In terms of equipment parameters, the structural form, diameter, blade angle and rotation speed of the agitator are the key variables. In general, higher speeds provide stronger shear forces, but may introduce too much heat or cause foam to form. Material properties have significant influences, including initial particle size, solids content, viscosity, surface tension, and compatibility between components. The geometry of the handling vessel, the baffle setting, and the amount of material filled affect the flow field shape and mixing efficiency. Process conditions such as processing time, temperature control, and dosing sequence also need to be optimized according to the specific system. There is an interaction between various factors, and the appropriate operation window needs to be determined through systematic experiments.
Applications
Laboratory multifunctional stirrer disperser is widely used in the field of non-medical drugs. In the chemical industry, it is used to prepare nanomaterial dispersions, catalyst slurries, or polymer solutions. In the field of coatings and inks, it is used for pre-dispersion and grinding of pigments and fillers to ensure uniform color and performance. In the food industry, it can be used for homogenization research in the manufacture of sauces, dairy products and beverages. In the field of new energy, such as the preparation of battery electrode paste, it is a typical application. The cosmetics industry uses it to develop emulsification processes for creams and lotions. In addition, it is used in environmental science to prepare standard suspensions and in scientific research institutions for the study of basic fluid mechanics and mixing processes.
Selection considerations
Choosing the right multi-function mixer disperser for your laboratory requires a comprehensive evaluation of multiple indicators. First of all, the properties of the main materials to be processed, such as viscosity range, corrosiveness, and whether they contain abrasive particles, which determine the resistance requirements of equipment materials, motor power and mechanical structures. In terms of functional requirements, it is necessary to consider whether additional modules such as vacuum defoaming, temperature control or online monitoring are required. The speed range and speed regulation should meet different experimental scenarios, from gentle mixing to high-speed dispersion. Safety features such as overload protection, mechanical stability, and electrical safety certifications cannot be ignored. The user-friendly design of operation, including the clarity of the control interface, the stability of the lifting mechanism, and the convenience of cleaning and disassembly, affects the long-term use experience. Finally, it is necessary to refer to relevant international or national standards to ensure that the design and performance of the equipment meet the requirements of common test methods in the industry.