Definition
The shear grinding and dispersing machine is a composite laboratory sample preparation equipment that integrates high-speed shearing, fine grinding and efficient dispersion. It uses a synergistic combination of mechanics and fluid mechanics to homogenize, emulsify, pulverize and disperse various samples, aiming to obtain homogeneous and stable mixtures or suspension systems. This equipment is widely used in laboratory sample preparation in various fields such as materials science, food testing, chemical research and development, environmental analysis, and coating inks.
Principle
The working principle of the shear grinding disperser is based on the high-frequency mechanical action and fluid shear force generated by the rotor-stator structure. The motor drives the rotor to rotate at high speed within the stator, creating a strong radial suction force that draws the sample into the working chamber. In the narrow gap between the rotor and the stator, the sample is subjected to extremely high shear rates and impact forces, resulting in the breakage of solid particles, the refinement of droplets, and the uniform mixing of different components. Its core role can be summarized as the combination of mechanical crushing and fluid dispersion, and the process follows the basic fluid mechanics and particle crushing energy transfer laws.
Evaluation methodology
The evaluation of the treatment effect of the shear grinding and dispersing machine usually relies on the determination of the physical index of the output sample. Particle size distribution is the core evaluation parameter, which can be measured by laser diffraction or dynamic light scattering method, and the pulverization fineness can be characterized by characteristic particle sizes such as D50 and D90. Dispersion stability can be judged by standing observation of stratification time, centrifugal sedimentation experiments, or zeta potential measurements. In addition, viscometers can be used to evaluate changes in the rheological properties of systems before and after treatment, and microscopic observation can intuitively judge the uniformity and morphology of particles or droplets. These methods are implemented according to specific industry standards or internal specifications.
Performance Factors
The treatment effect of the equipment is affected by multiple factors. In terms of equipment parameters, rotor line speed, rotor-stator clearance design and shape, processing time and number of cycles are the key variables. The sample characteristics include initial particle hardness and size, material concentration, system viscosity and temperature sensitivity. Operating processes such as feeding sequence and cooling control also affect the final result. There is an interaction between various factors, and it is necessary to determine the appropriate process window under a specific system through systematic experiments.
Typical application areas
In the field of materials, it is used for the preparation and dispersion of slurries of nanomaterials and composite materials. In the food industry, it is suitable for homogeneous emulsification of sauces, dairy products and other samples. In the chemical and coatings industry, it is used for dispersion and stability testing of pigments and fillers in bases. In terms of environmental detection, it can be used for grinding and homogenizing solid samples such as soil and sediment for subsequent analysis. Its versatility makes it a common device in laboratories requiring efficient mixing and particle size control.
Key points for equipment selection considerations
Selection should be based on specific sample characteristics and treatment goals. The physical and chemical properties of the sample, such as hardness, viscosity, sensitivity to temperature, and processing volume, need to be considered. The technical parameters of the equipment, such as power, speed range, corrosion resistance of the rotor stator material, and whether it has vacuum defoaming or temperature control functions, should match the application requirements. In addition, the ease of operation, the complexity of cleaning and maintenance, and the safety protection design of equipment are also important practical considerations. It is recommended to verify the suitability of the equipment through sample trial treatment.