The purpose and content of automotive pre-treatment
Painting is an important link in the surface manufacturing process of products, and it is an important way to obtain the decorative, weather resistance, corrosion resistance, durability and certain special functions of industrial products. It is widely used in automobiles, construction machinery and ships. In the big industry. For the automotive industry, pre-treatment is an important process section of a coating production line. It is a basic process that provides a clean coating substrate and ensures the adhesion of the coating film. It plays a decisive role in the performance of the coating film. Next, I will introduce the purpose and content of pre-treatment of automobile.
1. Purpose of pre-painting
The pre-painting treatment is mainly to remove all dirt on the surface of the coated object (such as turbidity, rust, scale, dust, molding sand, welding slag, salt and alkali spots, etc.). By using a chemical method to generate a layer of non-metallic conversion film that is beneficial to improving the corrosion resistance of the coating, it is ensured that the coating has good corrosion resistance and decorative performance.
2. The main contents of pre-painting
Generally speaking, before entering the pre-treatment of any material workpiece, it should be pre-cleaned to remove excessive dirt that cannot be removed by cleaning. Pre-cleaning can greatly reduce the pollution of the subsequent pre-treatment and reduce the burden of each process tank of the pre-treatment. Pre-cleaning is generally performed manually.
Degreasing is the removal of oil from the surface of the workpiece. Various oil stains on the workpiece not only hinder the formation of the phosphating film, but also affect the adhesion, drying performance, decorative performance and corrosion resistance of the coating. Degreasing, degreasing and phosphating are very important to the performance of the entire coating.
(3) Surface adjustment
The use of surface modifiers to adjust the metal surface can eliminate the unevenness of the surface state caused by processes such as lye degreasing or pickling and rust removal, so that the metal surface forms a large number of extremely fine crystal centers, thereby accelerating the phosphating reaction , Facilitates the formation of phosphating film. For high-quality automotive painting, surface adjustment before phosphating has become an indispensable process.
The so-called phosphating treatment refers to a surface chemical treatment method in which a metal surface is brought into contact with an acidic solution containing a dihydrogen phosphate and a chemical reaction occurs to form a stable insoluble inorganic compound film layer on the metal surface. The resulting film is called phosphorus Chemical film. Phosphated film has a microporous structure, is relatively stable under normal atmospheric conditions, and has a certain rust resistance. Used as the bottom layer of a paint film, it can significantly improve the adhesion and corrosion resistance of the coating. As the bottom layer of electrophoretic paint, phosphating film has been used almost 100% in the automotive industry.
In the pre-treatment process of coating, the main purpose of water washing is: one is to wash the residual drugs from the previous process to avoid bringing them to the next process; the other is to prevent the workpieces from drying during the process and causing poor quality. Wash at room temperature.
The above is the related content of "the purpose and content of pre-treatment of automobile painting". The information is provided by Guangdong Chuangzhi, a 25-year painting production line manufacturer. For more information about the painting production line, please follow us for updates!