What are the functions and performance requirements of primer?

[DawsonLee]

Primer is the first layer of the paint system, mainly used to improve the adhesion of the topcoat, enhance the fullness of the topcoat, provide alkali resistance, and offer anti-corrosion functions. Below is an introduction to primer: 1. Concept: Primer refers to the coating directly applied to the surface of an object as a solid foundation for the topcoat. It must adhere firmly to the surface to enhance the adhesion of the upper coating and improve the decorative quality of the topcoat. Depending on the painting requirements, primers can be categorized into first-coat primers, second-coat primers, etc. 2. Functions: As the first layer of the paint system, primer is used to improve the adhesion of the topcoat, increase its fullness, provide alkali resistance and anti-corrosion functions, while ensuring uniform absorption of the topcoat for optimal performance of the paint system. The notion that a high-quality topcoat eliminates the need for primer is incorrect, as the functions of the topcoat and primer differ. The topcoat focuses more on final decoration and appearance, whereas the primer emphasizes improving adhesion, anti-corrosion functions, alkali resistance, etc.