99国产视频-www毛片-亚洲黄色小视频-午夜精品国产-超碰首页-在线综合网-久久综合婷婷-超碰777-成人av入口-天天操人人-欧美男女性生活视频-国产精品一级视频-亚洲伦理影院-亚洲丝袜色图-不卡av免费在线观看

 

In the automobile coating process, the top coat is the last process of Z. with the continuous development of the automobile industry, many manufacturers now use baking paint. If there is a problem after finishing, it is Z troublesome. The following atomic ash manufacturers will make a brief introduction according to the problems in production.

 

1. The top coat foams after baking.

 

Scrape off the bubbles after the bubbles of the top coat and see which layer the bubbles are on. If the bubbles appear in the primer layer, the atomic ash is well combined with the primer, and the substrate treatment may not be in place; After blowing off the bubbles, it is found that there is a layer of primer on the atomic ash and the substrate. Then it may be that the primer is too thick or the primer is not dry enough.

 

2. Pinholes and depressions appear after baking the finish paint.

 

First of all, consider whether the pinhole has its own quality. Secondly, if pinholes appear when the quality of atomic ash is qualified, it is generally because the atomic ash coating and grinding technology is poor and the sand holes are not handled well. In addition, during the coating and scraping process, if the coating and scraping tool is improperly selected, it will also cause pinholes.

 

3. "Prickle" after baking the finish coat.

 

First, the climate is too humid and the water absorption of the atomic ash is too large. The polished atomic ash adsorbs a considerable amount of water. The topcoat is sprayed before the water volatilizes. A small amount of water is sealed under the paint film. Once heated, the water volume expands sharply and breaks through the paint film to form a "prickly heat". Second, the water absorption of atomic ash is qualified. After being dried by hot air, spray the top coat, and there is "prickly heat" after baking. Then it is possible that after spraying the top coat, the solvent enters the drying room before it volatilizes fully. In this way, because the surface of the top coat is closed soon, the residual solvent has to break through the paint film to form "prickly heat". Of course, it may also be the quality problem of the topcoat, or the mismatch between the polarity of the solvent and the topcoat