Why Can't the Yellow Stains on the White Car Be Washed Off?

[LeilaniAnn]

White cars with yellow stains that cannot be washed off are likely due to oxidation and yellowing of the white paint, often caused by inadequate paint maintenance. Below is an introduction to automotive paint: 1. Definition: Paint is a chemical mixture coating that firmly adheres to the surface of an object, serving purposes such as protection, decoration, marking, and other special uses. The authoritative book "Paint Technology" in China's coatings industry defines it as: "Paint is a material that can be applied to the surface of an object through various construction processes, forming a solid film that adheres firmly, has a certain strength, and is continuous. This film is commonly referred to as a coating, also known as a paint film or layer." 2. Composition: Paint generally consists of four main components: film-forming substances, fillers (pigments), solvents, and additives. Depending on performance requirements, the composition may vary slightly. For example, varnish lacks pigments, and powder coatings may not contain solvents.