High-speed mixer is the simplest type of dispersing equipment. Its main function is to pre-disperse the pigment and then disperse the pigment in conjunction with a sand mill.

High-speed mixer forms a turbulent zone through the high-speed rotation of a disc-toothed special impeller in the material. In this zone, the pigment particles are subjected to strong shear and impact, so that they are quickly dispersed into the paint slurry. However, no high pressure is generated at this time, and the pigment particles cannot be well deagglomerated. Outside this zone, a laminar flow is formed, which is divided into two upper and lower streams, so that the paint slurry is fully circulated and turned and mixed evenly.

The advantages of high-speed mixer are: simple structure, easy operation, maintenance and maintenance; flexible use, mixing, dispersing and blending processes can be used; easy cleaning and high production efficiency. High-speed mixer is one of the main production equipment currently used in architectural coatings factories.

High shear mixer is a rotor/stator mixer used for more challenging solid-liquid dispersions and emulsions, which cannot be fully handled by these high-speed dispersers. The typical feature of this type of mixing device is that the four-blade rotor rotates at high speed in a stationary stator. As the blades rotate, material is continuously drawn into the mixing head and gas is expelled at high speed through the opening of the stator (Figure 2). The resulting hydraulic shear promotes rapid homogenization, deagglomeration and emulsification. Typical rotor tip speeds are 3000-4000 feet per minute.

When large quantities of powder need to be added to liquids quickly, or when difficult-to-disperse solids take a long time to be fully incorporated, it is necessary to consider a high shear mixer with a built-in device for adding powder below the liquid surface. Ejector-based powder injection systems, although effective in removing floating solids and providing more precise control during mixing, do suffer from frequent clogging and intensive equipment maintenance issues. In addition, these systems require experienced operators to handle the often difficult task of balancing the performance of three separate devices in series: ejector, pump and agitator. High shear mixers with integral powder injection are more reliable and easier to operate.