The dispersion method of the filler disperser can be selected based on the filler type, dispersion scale, and process requirements, including mechanical shearing, ultrasonic cavitation, grinding refinement, electric/magnetic field assistance, or chemical modification, or through the combination of multiple methods to achieve efficient dispersion. The following are specific methods and principles:
1、 Mechanical dispersion method
High speed mixer: By generating strong shear force through a high-speed rotating rotor, the filler particles are subjected to intense friction and collision in the material, thereby breaking the agglomeration between particles and achieving dispersion. This method is suitable for materials with low to medium viscosity, with good dispersion effect, but may have limited effectiveness for high viscosity materials.
Roller grinding method: using the shear force between rollers to disperse the filler. The raw materials are subjected to strong compression and shear between the rollers, causing the particles to break and disperse evenly. This method is suitable for high viscosity materials such as rubber, plastic, etc., with stable dispersion effect, but high equipment cost.
Sand grinding method: using a sand grinder, the material is input into a closed grinding chamber through a pump, causing strong collision, friction, and shear between solid materials and high-speed rotating grinding media (such as sand particles), accelerating the dispersion of aggregates. This method is suitable for applications that require high fineness dispersion, such as coatings, inks, etc.
High pressure homogenization and dispersion method: Using a high-pressure homogenization and dispersion machine, the material is subjected to the combined forces of turbulence, cavitation, shear, etc. through a high-pressure homogenization valve, thereby achieving ultrafine refinement of liquid substances or solid particles carried by liquids. This method is suitable for applications that require ultrafine dispersion, such as nanomaterials, biologics, etc.
2、 Ultrasonic dispersion method
The ultrasonic dispersion method utilizes the cavitation effect and mechanical vibration generated by ultrasound in liquid to subject the filler particles to strong impact and shear, thereby disrupting the agglomeration between particles and achieving dispersion. This method is suitable for the dispersion of nanoscale fillers, such as carbon nanotubes, nano silica, etc. Ultrasonic dispersion method has the advantages of good dispersion effect and easy operation, but it may require high equipment requirements and may generate heat during the dispersion process, requiring attention to heat dissipation.
3、 Grinding dispersion method
The grinding and dispersion method uses grinding media (such as grinding balls, grinding rods, etc.) to grind and shear the fillers, causing the particles to be crushed and uniformly dispersed. This method is suitable for applications that require high fineness dispersion, such as ceramics, pigments, etc. The grinding dispersion method has the advantages of good dispersion effect and controllable particle size distribution, but it may cause significant equipment wear and may generate heat during the grinding process, requiring attention to cooling.
4、 Electric or magnetic field assisted dispersion method
For certain fillers with conductivity or magnetism, dispersion can be achieved through the action of electric or magnetic fields. For example, by applying an electric or magnetic field, the filler particles are subjected to force in the electric or magnetic field to undergo directional movement or rotation, thereby disrupting the agglomeration between particles and achieving dispersion. This method is suitable for specific types of fillers, such as conductive fillers, magnetic fillers, etc.
5、 Chemical dispersion method
Chemical dispersion method changes the surface properties of filler particles by adding dispersants or surfactants, making them easier to disperse in the matrix. Dispersants or surfactants can adsorb onto the surface of filler particles, forming a protective film to prevent agglomeration between particles. Meanwhile, they can also reduce the viscosity of the matrix and improve the dispersibility of the filler. This method is applicable to various types of fillers, but attention should be paid to the selection and dosage of dispersants or surfactants to avoid adverse effects on the matrix properties.