Effect of drying and curing process on paint surface
Effect of drying and curing process on paint surface can be divided into three aspects, respectively, the heating stage, the insulation stage and the cooling stage.
The heating process refers to the rise of the paint layer from the normal temperature to the temperature that can make it dry. The time required for this process is called the warming time. In the process of temperature rise, the paint layer at normal temperature rises due to the absorption of a lot of heat, and the solvent inside the paint layer is heated and quickly volatilized. The length of the heating time affects the speed of heating, thus determining the speed of solvent volatilization, heating time is short, the speed of heating is faster, and the volatilization of the solvent is faster, and the drying process is greatly shortened. Otherwise, it is extended. Therefore, the heating time has a great impact on the quality of the paint film.
Heat preservation means that when the paint layer reaches the temperature required for drying, it no longer continues to heat up and remains unchanged. The time used in this process is the drying time. In the process of insulation, the solvent in the paint layer will gradually completely volatilize over time until the paint film solidifies. In this process, it is important to master the drying time, because the length of time determines the quality of the paint film formation. The length of drying time is affected by many factors, such as drying temperature, working state, etc., but the most important is the variety of paint. Different coatings have different properties and different colors, which lead to different infrared absorption. The deep color of the paint, the absorption rate is fast, the heat obtained in the low time is more, so that the drying time is shortened, and the light color of the paint is the opposite, its absorption is slow, the drying time is long. The size of the paint absorption spectrum also has an impact on the drying time, some paint absorption spectrum is wider, the absorption of infrared radiation is also more, drying time is short, some paint absorption spectrum is very small, the absorption of heat is less, so that the drying time is longer. Therefore, the choice of paint lamps is particularly critical. In the drying process, drying temperature and time are very important reference data, indispensable. They must meet the standard requirements of baking at the same time in order to achieve the best quality of baking paint. If in the drying process, the drying temperature meets the requirements, but the drying time is too short, it will cause defects of the paint film, such as the hardness of the paint film is small, easy to crack and other problems.
In the cooling stage, the temperature of the film is mainly lowered to normal temperature. There are many kinds of cooling methods, but most of the use of natural cooling, although this method will take a little longer, but it can make the effect of the paint film to the best. A small part of the cooling is artificial cooling, mainly divided into air cooling and water cooling, which method to use, mainly depends on the material of the film. Different material methods are also similar