Baking paint is generally used for HVLP car painting. In the automobile manufacturing plant, after the frame and shell are welded, the next process is painting. Pay attention to the following points in the car painting process.
Before HVLP car painting, the automobile spray gun and related equipment should be clean and in normal working condition. Check whether the car spray gun has an ideal spray shape. The ideal spray shape should be symmetrical, the atomization particle size is evenly distributed, the edge is clear, and there can only be a few paint mists outside the edge of the spray shape. The low atomization air pressure helps to generate the correct and uniform spray shape, reducing rebound and overspray.
The first skill of spraying is how to hold the gun correctly. The automobile spray gun and the workpiece to be sprayed should be kept vertical. When the automobile spray gun moves, its spraying trajectory should be parallel to the spraying surface, trigger the gun after each spraying stroke, release the gun before the end of each spraying stroke, before triggering the gun, the gun should be in motion, otherwise it will produce The local coating is too thick; keep the distance between the automobile spray gun and the workpiece constant; the spray gun should maintain a uniform motion during spraying; the spraying surface of the next spraying stroke should be consistent with the overlap of the spraying surface of the previous spraying stroke; for the same workpiece, the number of spraying strokes remains the same.
It includes the angle of the car spray gun to the surface of the coated object and the running speed of the spray gun. The spray gun should run at right angles and parallel to the surface of the object to be coated. The moving speed of the spray gun is generally adjusted between 30 and 60 cm/s, and is required to be constant.
If the car spray gun is skewed and runs in a circular arc or the moving speed is variable, a uniform thickness of paint film will not be obtained, and streaks and markings will easily occur; if the running speed of the car spray gun is too slow (below 30cm/s), it is easy to Sagging occurs.
There should be an overlap between adjacent spraying strokes, that is, the overlap rate, which should reach 50%-60%. It is not easy to get a smooth paint film if the lap is too fast or not too much. When the uniformity of the thickness of the HVLP automobile spray paint layer is required to be high, the cross spray method should be selected, and then the horizontal spraying should be done.