The cause of the color difference between the coating film and the electrostitive powder coating

In electrostitive powder coating, the color difference between the coating film is possible because of the problems of powder coating and powder coating process control.
From the powder coating itself, the general powder coating production plant is based on the user's requirements, according to the user's color card, model, physical or color card, and according to the user's baking temperature and time and other conditions for preparation. According to the conditions of both sides are consistent, the coating color is not good there is a great color difference
the
. If a color difference is produced in powder coating, one of the possible reasons is that the heat resistance of the raw materials selected in the formulation design, such as pigments, anti-light curing agents, etc., is not ideal, and there is a certain gap between the baking curing conditions of the powder coating plant and the baking curing conditions of the powder coating plant when the color is adjusted.
from the powder coating aspects, the following factors will affect the color difference of the powder coating film.
From the powder coating process, when the thickness of the coating film is not uniform, the color difference between the thin part of the coating film and the thick part is obvious, especially when the covering force of the powder coating is not very strong, the color difference between the coating film spray thinning and the spray thickness coating film is more obvious. In order to minimize the color difference of the coating film, in the powder coating, a certain degree of film thickness must be guaranteed, and the coating film thickness should be uniform.
from the powder coating process, the temperature control sensitivity of the oven is poor, and the coating film is easy to produce color difference when the temperature distribution is uneven. In order to reduce the color difference in baking curing, the temperature control sensitivity of the oven is required to be high, the temperature distribution should be uniform, from the point of consideration of the uniformity of temperature distribution, the film color difference caused by the hot air furnace is smaller than that caused by the infrared heating furnace.
in the powder coating baking process, baking time on the film color difference also has a significant impact. In particular, the thickness of the coating material is different, the heat capacity is different, if the material thickness difference is large coating hanging in the same oven baking curing, the coating reached the set temperature after the effective baking time is short, so that different material thickness between the coating is also easy to produce color differences. Therefore, when the powder is coated with those different materials, thicknesses, shapes and sizes, it should be classified according to the material, thickness, shape and size of the coating, and then set different baking times for baking curing, which can reduce the color difference of the coating film.
In powder coating, when changing the paint color variety, if the powder supply device, spray gun, powder room and powder coating recovery system cleaning is not clean, it is most likely to cause the front use of powder paint color on the back use of powder paint color pollution. In particular, when the color difference between the different paint varieties is large, it is more likely to cause the color difference of the coating film. Therefore, when changing the paint color variety, the powder coating and recovery system must be thoroughly cleaned in order to reduce or avoid the color difference of the coating film.