Car Paint

Many businesses will wonder what are the benefits of pearlescent pigments in automotive paints. Next, I will give you a specific introduction.

There are several general topcoats: ordinary paint; metallic paint; pearl paint. Needless to say, ordinary paints, resins, pigments and additives. The metallic paint has more aluminum powder; so it looks bright after finishing. For pearl paint, mica particles are added. Mica is a very thin piece of material, therefore, the reflection is directional and has a colorful effect. If it is metallic paint plus a varnish layer, the paint on the car looks very bright and beautiful. In terms of color, white is undoubtedly cheap. For example, the world-class brand red pigment is about 25 times more expensive than the world-class brand titanium dioxide; while the amount of titanium dioxide used in white paint is about 5 times that of the red pigment. Therefore, the cost of red paint for color is 5 times higher than that of white paint. This is why some domestic cars have so few color varieties: simple and low cost.

No matter what color paint, its pigment will fade in the sun. In fact, not only paint, but any colored stuff may fade under the sun. At this time, the additives added in the paint are very important. For example, light stabilizers, antioxidants, etc. Unfortunately, good additives are very expensive. In many cases, the quality of the additives determines how the paint feels. People would definitely think that a certain paint that began to show obvious fading in 2 years is as bright as new paint in 5 years. But in fact, there is no non-fading paint. In many cases, the factory is more concerned about: uniform fading. Try not to make chromatic aberrations appear in different parts of the car.

Craft skills:

1. Adjusting the gun for automobile painting process

Before spraying, the spray gun and related equipment should be clean and in normal working condition. Check whether the spray gun produces the ideal spray shape. The ideal spray shape should be symmetrical, the atomization particle size distribution is uniform, the edge is clear, there can only be a small amount of paint mist outside the edge of the spray shape, the low atomization air pressure helps to produce the correct and uniform spray shape, reducing rebound and overspray .

2. Car painting process with gun

The trajectory of the correct spraying is perpendicular to the surface of the workpiece. According to the angle of the coated surface during spraying, the distance between the spray gun and the sprayed surface is generally 15~30cm. To get a wetter, darker, and thicker coating, the distance can be closer; to get a drier, lighter, and thinner coating, the distance can be farther.

3. The car paint process takes the gun

The walking gun includes the angle of the spray gun to the coated surface and the running speed of the spray gun. Keep the spray gun running 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 spray gun is inclined and runs in an arc shape or the movement speed is variable, a uniform thickness of the paint film will not be obtained, and stripes and spots will be easily produced; if the running speed of the spray gun is too slow (below 30cm/s), it will be prone to sagging . 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 when the joint is too fast or not too much. When the uniformity of the paint layer thickness is high, the cross spray method should be used

Then do horizontal spraying.

Precautions.

1. For cars, motorcycles, and a class of objects with high decorative requirements, the pearl powder should be above 200 mesh, otherwise the soft luster similar to silk cannot be obtained. 2. Mica titanium pearlescent pigments must undergo surface modification treatment before they can be used in coatings.

3. Since high-decorative products such as cars have extremely high requirements on the gloss of the paint film, it is necessary to adopt a mechanical dispersion type.

   In addition, the thin layer of titanium dioxide on the surface of the mica titanium pearlescent pigment may be damaged and destroyed under mechanical action. Therefore, excessive shear force should be avoided during mechanical dispersion. A high-speed anchor type cargo frame mixer should be used. Ultra-fine pearlescent pigments need to be dispersed by a three-roll mill.

   The mass ratio of the pearlescent pigment in the pearlescent topcoat is generally controlled at 3%-8%. Through 6%, in order to increase the hiding power of the mica pearlescent pigment, a small amount of aluminum powder of the same particle size (usually 10% of the pearlescent pigment) can be added , The addition of aluminum powder improves the hiding power, but affects the gloss.

   When configuring the transparent topcoat with pearlescent pigments, the mass ratio of the pigment to the carrier is 1-3. The thinner pigment can make the base color more visible through the transparent pearlescent layer.

   Pearlescent pigments are generally put into the paint separately. Can not be mixed with opaque or light-scattering pigments such as titanium dioxide cadmium salt camelic acid pigments, high coloring rate pigments and ordinary iron oxide pigments.