In the process of powder coating manufacturing, the function of the raw material premixing equipment is to mix the solid particles or powdered raw materials such as resins, curing agents, pigments, fillers and additives in the powder coating formula evenly, and then provide for the next melt extrusion mixing process. Therefore, this powder device requires the ability to evenly mix and disperse solid particles or powdered materials in a short time.
There are many kinds of powder equipment that can be used for powder coating raw material pre-mixing, including cylindrical mixer, conical mixer, square mixer, double-barrel V-shaped mixer, barrel mixer, mixing mixer, twin-screw mixer (horizontal), screw mixer (vertical), ball mill, high-speed mixer, etc. According to the function of these equipment can be divided into three categories: roller mixer, stirring mixer and high speed mixer.
Among the above equipment, cylindrical, conical, square, double-cylinder V-shaped, barrel type and ball mill type mixers belong to roller type mixers, most of which only have mixing function without crushing function, only the ball mill has mixing and crushing dual function, and the mixing time of these equipment is 10? 30 minutes. The equipment used in the production of powder coatings are the improved three dimensional rotary water cooled mixer of cone type mixer, double barrel V type mixer and barrel type mixer. Most manufacturers use these devices for the blending of finished powder coatings or for the manufacture of fine art powder coatings (including metal powder coatings), while a few manufacturers use them for the pre-mixing of raw materials. When the resin and auxiliary particles are too large, the roller mixer is not suitable for pre-mixing raw materials. This is because this equipment has no crushing function, when the raw material has large particles of resin, especially polyester resin softening point and melt viscosity of high resin, in the process of melting extrusion too late to break and melt dispersion.
The undispersed resin particles are easy to appear in the extruder, and the shrinkage holes of the film are easy to occur.
Powder equipment of high speed mixer has both mixing function and crushing function. Generally, the mixing time is 3? Five minutes is a powder mixing equipment for making powder cooking.
This powder equipment is generally equipped with two or three motors, installed in the center of the mixing tank motor is to drive the mixing blade, the general speed is below 20 r/min, mainly plays a mixing role; The other one or two motors are installed on the side of the mixing tank, the general speed is 2900r/min, which drives the powder crushing hammer and mainly plays the crushing role. For the mixing tank with a capacity of more than 500L, two motors are installed. High speed mixer for thermosetting powder coating, generally not equipped with cooling device, this mixing equipment structure is simple, there is no dead Angle in the tank, cleaning machine, color change and paint varieties are convenient, most of the domestic manufacturers use this equipment for raw material mixing. In addition, there are also some foreign factories and some large powder manufacturers in China choose the automatic mixer as the hopper mobile (tipping bucket) mixer.
Domestic large manufacturers have such equipment. The working principle of this mobile mixing hopper is that after the hopper is pushed to the station, it is lifted by the automatic control system, combined with the mixing cap and locked. The hopper is turned over with the stirring cover, mixing as it is turned over. After the mixing process is completed, the hopper automatically returns to its original station. The whole working cycle is automatically controlled by PLC. Mixed evenly, high production efficiency, no solidification particles.
The advanced technical characteristics of the rotary automatic mixer are: the hopper flipping and mechanical mixing at the same time; Multi-hopper continuous cycle operation, convenient color change; Mixed evenly, no solidified particles; High productivity, electromechanical control hopper positioning, lifting, clamping and loosening; Using programmable logic controller (PLC) to realize automation; Easy to clean and repair.
Because the powder equipment of the powder coating factory size, variety and economic conditions of the difference is larger, and the difference between the traditional habits and economic conditions of the factory is larger, and the traditional habits and experience of the factory is not exactly the same, so according to the actual situation of the factory, choose suitable mixing powder equipment.