Why thermal spraying is still so popular in the paint industry

       In the past, paint was brushed. This is limited to wood and home decoration. For car paint, only the method of spraying is beneficial for long-term maintenance. The method of thermal spraying for paint has a history in the early 20th century. Why is it still used today?



Mainly because thermal spraying uses oxygen-acetylene combustion as a heat source, and the spraying material is a thermal spraying method of wire. The spray gun introduces acetylene, oxygen and compressed air respectively through siphoning, and the acetylene and oxygen are mixed to generate a combustion flame at the nozzle outlet. The wire feed wheel drives the wire to continuously send the flame through the center of the nozzle, and it is heated and melted in the flame. The compressed air forms a conical high-speed airflow through the air cap, and the molten wire is atomized into fine particles. Molten particles are sprayed onto the pretreated substrate surface to form a coating.



The coating structure of linear flame spraying of paint is an obvious layered structure, and the coating has more pores and oxide slag. For zinc and aluminum coatings, the porosity is 10%~15% during the spraying process. , The flow and pressure of the compressed air must be kept constant, otherwise the wire feeding will be fast and slow, which will seriously affect the melting effect of the wire.



These are the reasons why thermal spraying is still used for paints today, and the techniques for using thermal spraying.