What is the air cap? Where is it?
As we all know, the principle of the spray gun is the atomization of the liquid paint by high pressure and adheres to the object’s surface. The air cap achieves the most important and final process. The airflow cap is located on the outermost part of the gun head. There are many secrets of the gun from the outside of the air cap, consisting of tiny air holes and central air holes. At the same time, it has an inseparable link with the gun body, nozzle, needle, air passage, sealing parts, etc., which are directly related to the atomization effect and life of a high-quality spray gun.
Air cap generally comprises several parts: air cap ring, gasket, snap spring, and cap body.
What are the differences in the air cap on the market?
- Materials of the air cap body
Currently, there are two materials of air caps on the market-aluminum and brass made. The external cap ring is all made of aluminum. The material mentioned here refers to the main body of the airflow cap: copper body, wear-resistant, high precision processing. An aluminum body is cheaper and lighter in weight.
- Technique
The classification of airflow caps is divided into three categories, conventional, HVLP, and LVMP.
- Conventional Air Cap
The conventional air cap is suitable for high-pressure guns with inlet air pressure between 3.5Bar to 6.8Bar. The actual air pressure coming out of the airflow cap is between 3 to 10 bar. Those with regular atomization and environmental protection requirements usually choose this gun because it is inexpensive and available for most paints, suitable for beginners and consumers with a limited budget.
- HVLP(High Volume Low Pressure) Air Cap
Compared with the conventional air cap, the HVLP one is more complicated, especially for the size and precision of the air holes. HVLP, as the name implies, is the abbreviation of high volume low pressure, so the inlet air pressure is generally about 2 bar(29Psi), the actual air pressure out of the air cap is 0.7 bar, the air consumption is 430L/min. The central air hole of HVLP is larger than the other two, which is conducive to the airflow and the high-speed spraying of the paint. Its advantages are:
- Good atomization effect.
- Less bounce and overspray.
- Saving paint and appropriate for spraying low viscosity paints.
- LVMP(Low Volume Middle Pressure) Air Cap
The LVMP means low volume medium pressure. Compared to the large diameter of the HVLP, the LVMP central air hole is smaller. The inlet air pressure is 2.5 bar, the actual air cap comes out at 1.8-2 bar, and the air consumption is 290 L/min. The atomization effect is as well as HVLP, but the spraying speed is faster than HVLP. It belongs to the Eco version of spray guns, which less impacts the environment and the painter’s health.
How to maintain the air cap
- Frequent issues – clogging and damage
Clogging on the air cap often occurs due to the lack of thorough cleaning and improperly unblocking after use. Because the holes on the airflow cap are tiny, a long time accumulation will clog. Using a rigid needle tool to remove them will change the shape of the holes and cause permanent damage, thus affecting the condition and effect of the atomization.
- Solution
The correct way should be to clean up after use, add cleaner or water to the paint cup and squeeze the trigger to make a high-speed airflow to spray out any remaining paint in the gun. Repeat until there is no foreign material. If still found the residue on the air cap, use a special soft needle and a small brush to unclog it. With this in mind, our company has developed a particular set of tools for cleaning the small holes, with the following steps.
