Powder coatings are powder coatings, which are mainly divided into thermoplastic powder coatings and thermosetting powder coatings according to different film-forming materials.
The former is limited in application due to its poor glossiness, leveling and adhesion with metal, and is mainly used in the painting and finishing of automobiles and electrical appliances.
Next, we will explain the role of low viscosity oxidized polyethylene wax in powder coatings:
Conventional powder coatings contain 50-60% of adhesives, resins and hardeners, 40-50% of pigments and fillers, and 1-2% of additives. These ingredients are mixed in a mixer of appropriate size to obtain the so-called root compound, and then the root compound is extruded. During this process, the raw materials are condensed and blended into an average lump. After a few seconds, the temperature of the material reaches about 100 ° C after passing through the extruder, In the extrusion process, the oxidized wax acts as a smoothing agent to reduce the pressure and increase the output.
The oxidized wax also helps to improve the wetting of the resin mixture to pigments and fillers.
The slurry is pressed by a pair of cooling rollers and cooled on the cooling belt. After the material is cooled and crushed, it is ground to the particle size required by the customer. Since the oxidized wax is crystalline, the efficiency of the grinding stage is increased.
The powder coating is fluidized or mixed with compressed air so that it can be pumped into the spray gun and then charged. During the construction, the oxidized wax reduces the risk of block, and the nozzle will not wear out quickly.
During heating, the powder wax particles solidify and blend into a hard solid coating, which can improve the external hardness, scratch resistance, scratch resistance and glossiness of the final coating film.
The oxidized wax powder can also play the role of an active agent, which reduces the viscosity of the system, thereby reducing the mobility of the resin, so that the appearance is more even and the glossiness is higher.
The addition amount of oxidized wax in powder coating varies from 0.2% to 1.5%.