In the field of electrophoretic coating, the appearance of watermarks on the surface of workpieces is a "major headache" that troubles many people. Those foggy, semi-transparent watermarks that can't be wiped off no matter how hard you try severely affect the appearance quality of products, making them instantly "lose value." Don't worry, today I'm going to share several practical treatment methods with you to help you easily get rid of watermarks on electrophoretic paint.

　　Many times, the complex structure of workpieces, with gaps and recesses, makes them particularly prone to water retention. When workpieces with this retained water enter the high-temperature baking area, the water reaches its boiling point and starts to boil, splashing onto the paint film and causing watermarks. If we can improve the hanging form of the product or drill some process holes without affecting its structural performance, we can prevent water retention in the workpieces. For example, some automotive parts have complex structures. By reasonably designing the hanging method, workpieces can drain water better during the coating process, greatly reducing water retention and the likelihood of watermarks. Just like some automotive components with complex structures, by reasonably designing the hanging method, workpieces can drain water better during the coating process, significantly reducing water accumulation and the chance of watermarks.

　　In addition to structural issues of workpieces, bringing water into the oven is also a common cause of watermarks. After electrophoresis, if the workpiece still has retained water on its surface and enters the high-temperature baking area, the boiling water causes the "biting" phenomenon, making the paint film uneven and forming watermarks. Regarding this situation, we can increase water-blowing equipment in the coating and draining area or enhance the blowing force while extending the draining process. For instance, some large automobile manufacturing plants have installed highly efficient water-blowing devices on the electrophoretic coating line, conducting all-round and thorough water-blowing for workpieces to ensure no water remains on their surfaces before entering the high-temperature baking area, effectively preventing watermarks.

　　Moreover, the environment of the draining area is also crucial. If the draining area is too humid and poorly ventilated, the water on the workpieces can't evaporate in such an environment and will enter the high-temperature baking area with retained water, resulting in watermarks. Therefore, we need to improve the ventilation in the draining area and reduce the air humidity. Industrial dehumidification methods, such as refrigeration dehumidification or adsorption dehumidification, can be adopted according to the actual situation. In some small electrophoretic coating workshops, installing small dehumidifiers can maintain a dry and well-ventilated air environment in the draining area, providing a good draining environment for workpieces.

　　In addition to these methods targeting specific causes, there are also some auxiliary measures to help us prevent and reduce watermarks. For example, when entering the drying oven, avoid over-hasty temperature increases; we can add a pre-heating link to allow the water on the surface of workpieces to evaporate slowly, preventing water droplets from boiling rapidly and leaving traces at high temperatures. At the same time, regular maintenance and upkeep of electrophoretic coating equipment can also improve coating quality and reduce problems like watermarks.

　　Although watermarks on electrophoretic paint are common, as long as we identify the causes and adopt the correct treatment methods, we can effectively solve this problem. In actual production, we should flexibly apply these methods according to the specific situation of workpieces and the requirements of the coating process, and constantly optimize and improve the coating process.

　　The issue of watermarks on electrophoretic paint is common, but as long as we find the root cause and adopt the correct treatment methods, we can effectively solve it. In actual production, we should flexibly apply these methods according to the specific situation of the workpiece and the requirements of the coating process, and continuously optimize and improve the coating process. I believe we can definitely enhance the appearance quality of products and present them perfectly to customers. I hope these methods can be helpful to everyone and free the electrophoretic coating process from watermark troubles.