The production of metal powder coatings includes melt extrusion method, dry mixing method, and bonding technology. The melt extrusion method is consistent with the traditional powder preparation process, except that metal pigments are added to the raw materials, and then high-speed pre dispersion, melt extrusion, tablet crushing, powder grinding and screening are used to produce finished products. Although this method is simple and the metal powder and base powder are uniformly mixed, the production process has a high-temperature basis and high-temperature shear, which can easily cause metal surface oxidation, metal particle crushing and deformation, and the sprayed profiles often do not achieve ideal metal effects. The dry mixing method is to add metal powder into a pre prepared base powder and mix it at high speed to produce finished products. The advantage of this method is that the metal powder is not easily damaged, and the metal effect after spraying is fully exerted. Its obvious disadvantage is that the separation phenomenon between the metal powder and the base powder is very obvious, especially during the spraying process, due to the inconsistency of gravity, shape, and charge with the base powder particles, the surface color difference of the profile and the metal effect are inconsistent. At the same time, it is easy to cause wear on the powder pump, Wenqiu tube, spray gun electrode needle, and flat nozzle. Bonding technology is an improvement on the basis of dry mixing method. After mixing metal powder and base powder evenly, the temperature is uniformly and stably raised to the softening point of the resin under inert gas protection, so that the base powder particles and metal powder particles adhere to each other, and even partially wrap the metal particles, thereby making the physical and chemical properties of the metal powder and base powder more consistent. This enables the metal powder to be well dispersed on the surface of the profile during the spraying process, achieving a good metal effect. Compared with bonding technology, the amount of metal powder added in dry mixing can only be controlled below 7%, while bonding technology can add up to 20%. With the maturity of its process, the application of bonding technology will be more extensive. In order to achieve the surface effect required by users, the material, specifications, and quality of metal powder are carefully selected. At present, there are many pigment factories worldwide, providing various types of metal powders. The more common types are aluminum silver powder, copper gold powder, and pearl mica powder. Aluminum silver powder is divided into floating and non floating types. Floating aluminum silver powder is easy to float to the surface of the coating, forming a layer of metal surface, but has poor chemical and weather resistance; The tendency of non floating aluminum powder is relatively weak, but it can bond well with the base powder. The physical and chemical properties of the coating are good, and it can achieve good metal effect. Non floating aluminum powder is usually surface treated, commonly including TiO2 coating, sol coating, and organic polymer treatment. The composition of copper gold powder is mainly copper or copper zinc alloy. In order to achieve a better copper gold effect, the surface of copper powder particles is often covered with a protective film, and the thickness of the protective film affects its light reflection and diffraction, resulting in a surface color of gold, red, antique copper or blue gold. The cross-section of mica powder is similar to the structure of pearls. Based on this principle, artificial mica powder wraps a layer of metal oxides with high refractive index, such as TiO2, Fe2O3, etc., on the mica chip. The high refractive index metal oxides and low refractive index mica chips are arranged in parallel, resulting in a visible rainbow color. If the thickness or ratio of metal oxides is controlled, the color of mica powder is more abundant.