Curing Oven

Curing temperature, time and coating effect:

The powder coating itself is only a semi-finished product. It only becomes the final product after being sprayed and cured. The consumer pays attention to the effect and quality after the coating is applied. That is to say, the use of powder coating is as important as the production of powder coating, low-quality powder,the spraying equipment is good, the pre-treatment is fine, the painting process is strict, and the high-quality products are not produced. The powder quality is good, the spraying equipment, the process and the pre-treatment have problems, and there is no high-quality product. However, the reality is that the attention of domestic coating companies is mostly concentrated on the powder coating products themselves. With the quality problem, only the powder is found, and the coating construction technology is not enough and the research is insufficient, so that a large number of coated products cannot meet the desired requirements. 

Each powder coating has its own curing characteristic curve, which can achieve complete curing within a certain temperature and time range. In order to improve efficiency and reduce cost, it is not advisable to reduce the curing time. If the curing temperature or time shortened, the curing will be incomplete, the performance should not be exerted, the physical properties will be greatly reduced, the chemical resistance will not be good, and the decorative, anti-corrosive and weather resistance will not achieve the expected results. Some low-temperature curing coatings do not have good coating properties after high-temperature curing. Especially for some workpieces formed after curing, fine cracks will form at the stamping and bending, and moisture will penetrate along the cracks. And quickly corrode the substrate, we can see the traffic barrier used outdoors, and soon after it is put into use, there will be traces of rust at the arc of the intersection, which is directly related to the baking temperature and time and the 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, the melting and solidification are almost simultaneous, the heating is rapid, the temperature rises rapidly, and the viscosity of the system decreases rapidly. The leveling process has been completed before gelation, so that the flatness of the plate surface is good and the orange peel is less. At the same time, the coating can be well wetted to the surface, which can improve its adhesion and durability. Due to the rapid curing, the internal stress of the film layer will be more, but since the coating film is thin, the physical properties are little affected. On the contrary, if the heating is slow, the viscosity of the system is always maintained at a high level. At this time, the curing has started, and as the reaction progresses, the viscosity is continuously increased, and the leveling effect is not good.

In general, if you want to heat up quickly and 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 time is too long, the solidification effect occurs before the powder coating melts, levels, wets the coated object and the physical properties are not satisfactory. At the same time, the volatiles are difficult to run away, resulting in premature coating damage under corrosive conditions, and the decorative and protective properties are not reflected.