Overview of the principles of dispersion
Laboratory dispersers achieve uniform distribution of coating pigments in liquid media through mechanical action. Its working principle is based on the combined effect of shear, impact and friction to destroy the pigment aggregates and achieve the desired fineness. The dispersion process is usually divided into three stages: wetting, dispersing, and stabilizing. The wetting stage allows the pigment surface to be fully encased by the medium; The dispersion stage produces strong shear through the rotor rotating at high speed to break the agglomeration. The stabilization phase prevents particles from reaggregating with additives.
Key parameter impact
The dispersion effect is affected by multiple parameters. Rotor line speed is one of the important factors, and its calculation formula is:
v = π × D × n / 60
where v represents the linear speed (m/s), D is the rotor diameter (m), and n is the rotational speed (rpm). Increasing the linear speed appropriately enhances the shear force, but too high can lead to a sharp rise in temperature or foam formation. In addition, the dispersion time, medium viscosity, pigment concentration and solid content need to be optimized and adjusted according to the specific system.
Equipment selection guide
Choosing the right dispersion equipment requires comprehensive consideration of material characteristics and process requirements. For high-viscosity systems, it is advisable to choose models with strong axial circulation capabilities. For materials that are easy to settle, it is necessary to pay attention to the suspension capacity of the equipment. The following comparison is for reference:
| Material viscosity range | Recommended device type |
| Low viscosity (<1000 mPa·s) | High-speed dispersion disk |
| Medium viscosity (1000-5000 mPa·s) | Serrated rotor |
| High viscosity (>5000 mPa·s) | Multi-stage shear rotor |
| Contains fiber or granular materials | Special tooth design |
Process optimization methods
Optimizing the dispersion process improves efficiency and ensures batch consistency. It is recommended to use the step-by-step speed method: the initial low speed makes the pigment initially wetted, and then gradually increases the rotation speed to the process value. Temperature control cannot be ignored, and the system temperature can be maintained by jacket cooling or intermittent operation. Dispersion endpoint judgment can be combined with fineness plate measurements, viscosity monitoring, or optical methods to avoid energy efficiency waste or performance changes due to excessive dispersion.
Maintenance & Safety
Regular maintenance ensures long-term stable operation of equipment. It should be cleaned in time after each use to prevent the material from solidifying and affecting the balance. The mechanical seal part needs to be inspected periodically, and the bearing should be kept in good lubrication. Safety regulations must be observed during operation: ensure that the protective cover is intact, and avoid long hair and loose clothing from touching rotating parts; The treatment of volatile media should be carried out in a ventilated environment; Abnormal vibration or noise should be stopped immediately for inspection.
Technology development trends
At present, decentralized technology is developing in the direction of intelligence and refinement. Integrated sensors monitor viscosity, temperature, and power consumption in real time for closed-loop process control. The modular design allows the same host to be adapted to multiple dispersion heads, increasing equipment flexibility. In terms of energy consumption optimization, the new rotor design reduces power consumption while ensuring dispersion. These advancements provide more reliable tools for coating pigment R&D and quality control.
Quote the instructions
The overview of the dispersion principle refers to the application of fluid mechanics in the mixing process. The formula in the influence of key parameters comes from the basis of rotating mechanical kinematics. The data of the equipment selection guide table is integrated from a number of technical reports on industrial dispersion equipment; The process optimization method draws on the chemical process optimization case set. Maintenance and safety content is in accordance with the general laboratory equipment operating specifications; The information on technology development trends comes from the literature review of scattered technologies in recent years.