Coating production line suppliers provide you with auxiliary processes in coating process

What are the auxiliary processes in painting process? Our company's personal explanation:

With the rapid development of domestic coating technology and management, great attention has been made. The coating process is generally composed of the main process. The number of the process depends on the decoration and the function of the coating. There are dozens or even hundreds of processes for the occasions with high requirements. However, in terms of the content and essence of the process, the coating process is composed of three basic processes, including coating pretreatment, coating and drying, and several auxiliary processes.

The auxiliary process is not an indispensable process to form the coating process, but a coating process that plays an auxiliary role in the main process or has special requirements for a certain product. It includes grinding, polishing, waxing, waxing, coating and sealing. Because it is an auxiliary process, many manufacturers do not pay enough attention to these processes.

1、 Burnish

Grinding is divided into dry grinding and wet grinding. Dry grinding does not need to be wetted by water. Wet grinding is to lubricate the coating with water or other wetting agent at the same time, so as to obtain a smoother surface and wash off the grinding dust. For example, when wetting nitro lacquer and perchloroethylene paint, it is not only wetted with water, but also moistened with pine perfume. In order to improve the decoration of the top coat, it can be ground with very fine sandpaper before polishing, or soapy water as wetting agent. The main purpose of grinding is to:

1. Remove the burrs and sundries on the surface of substrate, such as floating rust, etc;

2. Eliminate the particles, roughness and unevenness of the coating surface of the workpiece. For example, the surface scraped by putty is generally rough and uneven after drying, and it needs to be polished to obtain a smooth surface;

3. Enhance the adhesion of the coating. The adhesion of the coating on the smooth surface is poor, and polishing can enhance the mechanical adhesion of the coating, so polishing is one of the important operations to improve the coating effect.

Generally, rough or fine abrasive cloth, wood sandpaper, etc. are used to polish the surface of substrate. The putty layer for grinding and filling pits is generally made of fine emery cloth or grindstone. Emery cloth and wood sandpaper are only suitable for dry grinding. Water resistant sandpaper (water sandpaper) shall be used for wet grinding of intermediate coat and topcoat coat. According to the abrasive particle size of water-resistant sandpaper, there are several numbers. The higher the number, the smaller the abrasive particle size and the finer the sandpaper.

When grinding, the matters needing attention mainly include:

1. Grinding materials shall be selected in strict accordance with the process requirements. Dry grinding putty shall use 80 ᦇ 120 ᦇ water sandpaper; wet grinding intermediate coating shall use 240 ᦇ 320 ᦇ water sandpaper; wet grinding topcoat coating shall use 360 ᦇ and 400 ᦇ 600 ᦇ water sandpaper, and no sandpaper traces shall be left. At the same time, the quality of water-resistant sandpaper should be checked before grinding, and there should be no mechanical impurities (coarse sand) to prevent scratching the film. Water resistant sandpaper to tear use, should first wet with water, and then tear or fold use;

2. Attention should be paid to the direction of grinding. It is not suitable to grind randomly in all directions. It is not suitable to press too tightly when grinding. In order to improve the smoothness of the polished surface, cork or rubber grinding block can be padded on the sandpaper during manual grinding. The cork grinding block is suitable for polishing putty in medium coating situation, and the rubber grinding block is suitable for medium coating or topcoat;

3. In the process of grinding, the grinding ash should be removed continuously. After wet grinding, the deionized water should be used to wash thoroughly and blow dry to make the coating dry;

4. The coating can be polished only after it is completely dry, otherwise the sandpaper will stick to the coating during polishing, which will affect the polishing quality.

Because the grinding is generally manual operation, sometimes with the help of pneumatic tools or some simple instruments, so the labor intensity of grinding is high, so we are trying to eliminate this work in the industrial coating of flow production.