Question: What kind of compressed air do I need for vehicle body painting?
Answer:
Contaminants in compressed air
The compressed air produced by the compressor contains the same substances as the ambient air. This means, among other things, that the water vapor contained in the air, is compressed and the compressed air, therefore, has a high humidity. Compressed air from an oil-injected screw compressor also contains small oil residues from the compressor lubrication system. The average value, for screw compressors oil content, is about 3ppm. When the compressed air is to be used for eg body painting, there is a higher demand for air quality, than in many other applications. The requirements referred to above apply in particular to what is accepted in terms of contaminants such as water, particles, and oil.
Removing contaminants for vehicle body painting
We recommend that the humidity is always to be reduced by drying. This is easiest and cheapest done with a refrigerant dryer that gives a pressure dew point of about 3 degrees Celsius. We also recommend installing particle filters, to reduce the amount of particles that come into the compressed air. In addition to particle filters, you should also install an oil separating filter, that removes the residual amount of oil, that always comes with compressed air when you have an oil-injected screw compressor. If you want to be absolutely sure, that no oil will be included in the compressed air, you can complete the filters above with an activated carbon filter. When supplementing other filters with an activated carbon filter, one achieves a quality called "technical oil-free" compressed air.
Information provided by Chicago Pneumatic
