【 Building materials network 】 powder coating It is only a semi-finished product. It can only become a real product after spraying and curing. What consumers pay attention to is coating The effect and quality after coating, that is to say, the use of powder coating is as important as the production of powder coating. Low quality powder, Spraying equipment No matter how good it is, no matter how meticulous the pretreatment is, no matter how strict the coating process is, it will not produce high-quality products; No matter how good the powder quality is, if there are problems with the spraying equipment, process and pretreatment, there will be no high-quality products. However, the reality is that most of the attention of domestic coating enterprises is focused on the powder coating products themselves. If there are quality problems, only look for problems on the powder, but not enough attention and research on the coating construction process, resulting in a large number of coating products can not achieve the desired effect.

Each kind of powder coating has its own curing characteristic curve, which can achieve complete curing within a certain temperature and time range. It is not advisable to shorten the curing time in violation of the law in order to improve the curing rate and reduce costs. If the curing temperature or time is not enough, it will result in incomplete curing, failure to exert its due performance, and its physical characteristics will be greatly reduced, The chemical resistance is not good, and the decoration, corrosion resistance and weather resistance are not as good as expected. Even if the coating cured at low temperature is completely cured, its performance is not as good as that of the coating cured at high temperature. In particular, some workpieces formed after curing will form small cracks at stamping and bending places, and moisture will permeate along the cracks and quickly corrode the substrate. We can see the traffic barriers used outdoors, Soon after being put into use, rust will appear at the arc turning of the intersection, which is directly related to the baking temperature, time and bending after spraying.

Some people think that the heating temperature is lower, the reaction speed is lower, and the leveling can be better. In fact, the opposite is true, because after the powder is sprayed, its melting and curing are almost carried out at the same time, the heating is fast, the temperature rises fast, the system viscosity decreases rapidly, and the leveling process has been completed before gelation. Such a plate has good leveling property, and there are few orange peel substances. At the same time, the coating can wet the surface well, improve its adhesion, and have good durability. Due to rapid curing, the internal stress of the film will be more, but due to the thin film, the physical characteristics will have little impact. On the contrary, if the heating is slow, the viscosity of the system will always remain at a high level. At this time, the curing has begun. With the progress of the reaction, the viscosity will continue to rise, and the leveling effect will not be good.

In a word, if you want to heat quickly to reach the curing temperature in a short time, you can get the ideal coating effect and long-term protection function. If the heating temperature is low and the heating time is too long, the curing will occur before the powder coating melts, flattens and wets the coating, and the physical quality is not ideal. At the same time, volatile matter is difficult to escape, which leads to early damage of the coating under corrosive conditions, and the decorative and protective properties cannot be reflected.