Why does the automobile industry like powder coating?

Who hasn't got a car yet? However, in addition to the performance of the car itself, people often care about its coating, on the one hand, for the sake of good-looking, on the other hand, coating can also play a good role in protecting the car body.

At present, there are many kinds of coatings that can be used for automobile coating, but powder coating is obviously more popular. In Europe and America, the application of powder coating has been widely used; in Asia Pacific, influenced by environmental protection policies and clean production concept, the development potential of coating online coatingol.com can not be underestimated. What makes powder coating become the trend of automobile coating? The characteristics of powder coating powder coating, as the name implies, is a kind of solvent-free, 100% solid coating, which is usually sprayed on the surface of the coating in the form of powder, baked, melted and leveled, and solidified into a film.

It is composed of resin, pigment, filler, curing agent and auxiliary agent, and can be divided into epoxy resin, acrylic resin, polyester resin and other systems. Epoxy resin system is hard and tough, which can provide excellent mechanical properties, chemical resistance and solvent resistance, but its thermal stability, light resistance and weather resistance are poor; polyester resin system has excellent thermal stability and weather resistance; acrylic resin system has good appearance effect and excellent light and color retention, which is commonly used to prepare decorative coatings. With the improvement of spraying technology and powder performance, the application of powder coating in automobile has been able to meet the coating requirements of automobile, such as decoration, weather resistance, chemical resistance, scratch resistance, UV resistance and so on.

At present, it is mainly used in the automobile industry for the coating of automobile engine, chassis, wheel hub, filter, control rod, reflector, wiper, horn and other parts as well as interior decoration. In addition, with the development of coating types, powder coating has been used in the varnish and middle coating parts of automobile body multi-layer coating. Workers are spraying auto parts. At present, powder electrostatic coating technology is widely used in auto industry. Take the hub of spraying car as an example to explain its working principle: the spraying gun is connected with the compressed air pipe, after pressing the trigger, the compressed air enters the spray gun hopper through the pipe, and pushes the powder through the gun barrel. And the electromagnetic coil installed in the barrel makes the powder passing through have positive charge, and at the same time, there is negative charge under the wheel through the wire ground strap, so that the powder can be automatically attracted and coated on the wheel surface. However, it should be noted that the size of powder particles will affect the coating quality.

For example, too large particles will fall off before reaching the workpiece surface due to gravity, resulting in a decrease in the powder loading rate; when the particles are less than 10 μ m, they are basically not charged and easy to absorb moisture and agglomerate, affecting the spraying; therefore, for automotive powder coating, the fineness of powder coating is between 10 and The effect of 80 μ m is the best, and the narrower the distribution, the better the effect. The application advantages of powder coating refer to the advantages of powder coating. First, it does not need to dissolve the film-forming substances in the volatile organic solvent for coating construction, so the obtained coating film has no pinhole defects, which not only saves resources but also avoids environmental pollution. Second, one coating of powder coating can achieve the thickness of several or even more than ten coatings of solvent or water-based coating The third is that the coating of powder coating is not affected by the temperature, and can be effectively recycled and reused by dust collector and other equipment. But most importantly, the physical and chemical properties of powder coating are better than that of traditional solvent coating. For example, wear resistance and weather resistance.

It should be noted that the better the performance of these two aspects of automobile powder coating is, the longer the life of the paint film will be, especially for the car wheels, off-road vehicle metal chassis and roll cage and other parts which have been in the harsh environment of mud, rain erosion and sun exposure for a long time. Their requirements for the paint film will be more stringent than other parts, and polyester powder with better thermal stability and weather resistance will be used The coating shall be applied to avoid rusting. According to the industry survey, the powder coating for wheels accounts for about 25% of the sales volume of the whole automobile powder coating, which is the largest part of the market share. Note that powder coating is not omnipotent. It can't prevent the wheels from entering the high-quality surface. It has excellent corrosion resistance, heat resistance, impact resistance and wear resistance, and a wide range of color choices. All of these reflect the maturity of powder coating. No wonder its momentum is so fierce in recent years. But it doesn't mean that powder coating has no disadvantages at all. Its biggest problem is "heavy". So if you want to use it in some places sensitive to weight, you have to think twice.