Air spraying tips

Although traditional air spraying can provide users with good atomization effect and good coating quality, there are also some serious problems:

1. Low paint utilization rate: Generally, the paint utilization rate of the traditional air spray gun is about 35%, that is to say, nearly 65% of the paint of the traditional air spray is wasted in the operation. Most of them fly in the air, spray room and the floor.

2. Large air consumption: the traditional air spray gun needs 8 ~ 17 cfm of air to atomize the fluid during operation.

3. Low spraying efficiency: Due to the thin film thickness of the traditional air spray gun, it is generally necessary to repeatedly spray to achieve the required film thickness, so it cannot improve the efficiency of production.

In addition, the traditional air spray gun generally requires an air pressure of 40~90 psi to completely atomize the paint. As a result, the traditional air spray gun will produce a large amount of flying paint mist when spraying, which will not only cause environmental pollution, but also cause serious harm to human health. For this reason, the California government issued the "National Emission Standards of Hazardous Air Pollutants (NESHAP)" in 1996, which specifically restricted the paint mist flying during spraying. All painting industries are required to achieve more than 50% paint utilization when spraying, in order to reduce the content of harmful pollutants in the air.

In order to comply with the relevant regulations of paint utilization in NESHAP, scientists all over the world invented "High Volume Low Pressure Air Spraying (HVLP)" in the mid-1990s. The principle is to use a large amount of compressed air and a small amount of atomization pressure (10 ~ 19 psi) to atomize the paint, so as to increase the utilization rate of paint and reduce the paint mist flying purpose.

After HVLP came out, it immediately replaced the traditional air spraying and was used by most of the coating manufacturers in the world. Although HVLP can increase the paint utilization rate to 65%, there are still two serious problems:

1, can not atomize high viscosity paint: Since HVLP atomizes paint by high air volume and low air pressure, rather than high atomization pressure of traditional air spraying, HVLP limits the viscosity of paint during spraying. Generally speaking, its spray viscosity is below 18 seconds of Ford # 4. If it exceeds 18 seconds, the paint cannot be completely atomized. This reduces the applicability of HVLP.

2. Increased investment cost: Compared with the air consumption of traditional air spraying 8 ~ 17 cfm, the air consumption of HVLP 12~25 cfm is significantly larger, which will make the original air compressor is not enough to use, must be replaced with a larger air compressor, such as used in the central air supply system of the plant, the whole plant needs to replace a larger size of the air pipeline, so that, Investment will increase.

In view of the above shortcomings related to HVLP, the European spraying equipment manufacturer designed the "Low Volume, Low atomization pressure Air spray (LVLP)" in 1998 to solve this problem. Its atomization pressure is not much different from HVLP (10 ~ 21psi), but the air consumption is only 12 ~ 17 cfm, and the spray-able paint viscosity is much higher than HVLP's Ford # 4 18 seconds, LVLP's spray-able paint viscosity is up to Ford # 4 25 seconds, plus the high paint utilization rate of 65%, Making LVLP the most outstanding air spraying technology of the late 20th century. But LVLP did not replace the traditional air spraying and HVLP as expected in a short time, the key is speed, although LVLP can improve the utilization rate of paint, reduce the consumption of air, expand the scope of LVLP paint application, but because LVLP is based on the low pressure and low air volume atomization principle, Therefore, the spraying speed is much slower than the traditional air spray gun, which affects the overall production speed and increases the cost of production.

After understanding the advantages and disadvantages of HVLP and LVLP in various aspects, scientists who have accumulated more than a hundred years of experience in air spraying research and development finally invented a new air spraying technology "Low Volume Medium Pressure air spraying" in 2000, which is also a good effect. LVMP for short) ", through the patented air cap and unique gun structure design, so that LVMP not only spraying speed and atomization effect are superior to HVLP and LVLP, and air consumption only 9 ~ 12 cfm, effectively reduce the energy consumption, in addition, Although LVMP has a slightly higher atomization pressure (30 psi) than LVLP, its paint utilization rate is a staggering 72! Based on the above advantages, LVMP has become a representative invention in the painting industry at the beginning of the 21st century.

From the traditional air spray gun LVMP, along the way, this more than 100 years old technology, in order to meet the current of The Times, but also for the vast number of users around the world, constantly change and improve, so that today we can have the honor to enjoy the rich fruits of technology, therefore, we have reason to believe that in the future, Air spraying will continue to provide users with better atomization effect and lower energy consumption, so that the majority of users can really improve the quality of painting, reduce the cost of painting, improve the efficiency of painting.