The first is the smoothness of the paint surface. The paint surface is free of pits, bubbles, impurities and "flowing paint". These problems may exist. It is said that car painting is dust-free operation, but in 4S shops or repair shops, there will inevitably be some impurities and floating dust in the air, which will stick to the paint surface if it is not handled well. Moreover, if the thickness of the paint surface is not well grasped in the process of painting, if there is too much painting, the paint surface will have flowing traces, which will greatly affect the appearance. If there is dust on the paint surface, it can be solved by grinding the paint surface. If the paint quality is obviously too poor, you can ask for repainting, which is the right of consumers.
Matters needing attention in automobile painting: composition of coatings
Automobile paint generally has four basic components: film-forming substance (resin), pigment (including car body pigment), solvent and additive.
(1) Film-forming substance is the main component of paint, its function is to keep the pigment bright, firm and durable, and it can be attached to the surface of objects, and it is the substance that determines the type of paint. Generally, it is made of drying oil or semi-drying oil modified natural resin (such as rosin), artificial resin (such as dehydrated malic acid resin) and synthetic resin (such as methyl methacrylate, polyurethane, polystyrene, polyvinyl chloride, etc.). ). Its durability, adhesion, corrosion resistance, wear resistance and toughness are usually adjusted and improved by adding plasticizers and catalysts.
(2) Pigment is one of the two non-volatile substances in the paint, which endows the topcoat with color and durability, at the same time makes the paint have hiding power, improves strength and adhesion, changes luster, and improves fluidity and painting performance.
(3) Solvent is a volatile component in the paint, and its main function is to fully dissolve the resin in the paint film, so that the paint can be applied normally. High-quality solvent can improve the daubing performance and paint film characteristics of topcoat, enhance gloss and reduce paint reticulation, thus reducing polishing workload and contributing to more accurate color matching. In addition to the existing solvent in the coating, it is also used as a diluent to dilute the coating to make its viscosity suitable for painting requirements.
(4) additives. Great changes have taken place in coating technology in recent ten years, and the use of additives has become more and more common. Although the proportion of additives in coatings does not exceed 5%, they play various important roles. There are curing agents that can accelerate drying and enhance gloss, retarders that can slow drying, and matting agents that can weaken gloss. Some additives have comprehensive functions: reducing wrinkling, accelerating drying, preventing whitening and improving chemical resistance.