As environmental protection is becoming more and more demanding in all countries, the requirements for spraying operations are also increasing. Conventional spray guns will be used less and less frequently. High transfer efficiency, eco-friendly, and no harmful spray guns will gradually replace the original high energy consumption of the product. For the two standard atomization spray guns on the market, HVLP and APR (AIR PRESSURE REDUCED), we have conducted a comparative analysis as follows.
What is HVLP?
HVLP is the abbreviation of HIGH VOLUME LOW PRESSURE. High volume means high air volume, i.e., the air consumption can reach 430L per minute. Low pressure means low air pressure, where low pressure refers to the air pressure of the air inlet and atomization group. HVLP type guns can operate with air pressure between 0.5 and 2.3 bar at the air inlet and as little as 0.7 bar when spraying from the nozzle.
- Pros: less flutter, less bounce, paint transfer rate higher than 65%
- Cons: High air consumption, need good air source, the large diameter of the air pipe, so the required large air compressor—low production efficiency.
What is APR?
APR stands for AIR PRESSURE REDUCED, also known as RP/LVMP in the field, is a name for air pressure reduction. This type of gun reduces the air pressure and flow rate so that the overall air consumption is reduced to 290L/min, the air pressure at the inlet and HVLP is not much different, 0.6-2.5Bar, and the air pressure at the nozzle when sprayed with 1.5-2.0Bar. The atomized particles and fineness under this pressure are more uniform, the air compressor requirement is reduced, the working efficiency is enhanced at any time, and the painting rate is almost the same as that of HVLP, which is the more common atomization method at present.
- Pros: Combines advantages of HVLP while improving the transfer speed and speeding up work efficiency.
- Cons: Reduced fineness compared to HVLP
Spray width is more concerned when consumers buy, which is one reason for choosing an HVLP/APR spray gun. Compared to traditional spray guns, eco-friendly guns have a wider spray width, which is determined by the way they atomize and the paint transfer rate. Reduced air pressure and flow rate of the gun when spraying liquid, less dispersion, less bounce, attached to the surface of the paint film is relatively long, so we see the spray width is more expansive.
If you are a professional painter, you may also care about the spraying distance. Different guns are used at suitable distances to ensure perfect performance. It effects by atomization method, structure, paint viscosity, etc. The general spraying distance is around 20cm, which is the best atomization particle and shape—specific reference to the factory manual, or adjust according to the actual situation.
