There are many key factors that must come together in order to use electrostatic guns effectively. First you should select the proper atomization technology for the coating application needs. There are many electrostatic atomization technologies to select from. The oldest and probably most typical would be the air spray electrostatic guns. These guns use compressed air as their primary and sole means of atomizing the coating. These guns are most commonly found in applications that require a “Class A” automotive finish. The guns offer lots of control at the gun such as for example fluid flow by usage of the fluid needle adjustment knob and fan control through the utilization of the fan adjustment knob. Furthermore, the amount of fluid can be controlled by how far back the operator pulls the trigger. That is referred to as “feathering” the gun.
The key supply of fluid control is decided by the fluid pressure from a low-pressure pump, the air going into a stress pot or with a fluid regulator mounted near, or in the spray booth. The viscosity of the coating and the size of the fluid nozzle also affect the fluid flow. Although air spray electrostatic guns have great atomization, they are also the smallest amount of efficient of electrostatic guns. That is because of the potential usage of high air pressure to atomize the coating. The use of high air pressure can defeat the electrostatic attraction by forcing the charged particles of paint past the part or by creating excessive bounce back or overspray.
An alternative of the air spray electrostatic gun may be the HVLP electrostatic gun. The gun operates almost identically to the air spray gun except so it uses less atomizing air pressure. Instead, the gun uses more cubic feet of compressed air or CFM. The result is a gentler spray pattern which lowers the velocity at that the paint particles travel. polyurea This enables more of the charged particles to remain in the electrostatic field which helps to enhance transfer efficiency. Like any HVLP gun, some coatings may be too viscous or the application rate may be too high, which may allow it to be hard for the HVLP electrostatic gun to supply high productivity and acceptable finish quality for some applications. Furthermore, HVLP guns usually require more CFM that may result in increased electrical costs for compressed air.
For the application of very viscous materials and for very good application rates, some manufacturers use airless electrostatic guns. These guns use pumps to produce very good fluid pressure that is the primary means of atomizing the coatings. Once the gun is triggered, the high fluid pressure is allowed to escape to the atmosphere via a tungsten carbide tip that’s cut to create an elliptical spray pattern. The size of the pattern and the amount of fluid leaving the gun are controlled by the tip. The viscosity of the coating and the fluid pressure used also affects the application rate.
Generally, airless technology does not provide the exact same amount of atomization as air spray or HVLP electrostatic guns nevertheless they work well for some coatings, especially when spraying large products at high rates of speed. Tip plugging is an issue when spraying materials which contain an aggregate such as for example silica or zinc. Air-assisted airless electrostatic is really a hybrid version of the airless electrostatic and the air spray electrostatic. These guns use both fluid pressure and air pressure to atomize the coating. Pumps are needed to produce the fluid pressure. Since these kinds of guns use lower fluid pressure than airless and less air pressure than air spray, they can offer companies an excellent compromise involving the speed of an airless and a finish quality closer to the air spray electrostatic. The best part is that this technology is usually more efficient than either the air spray or the airless electrostatic guns. In some cases they are even more efficient compared to the HVLP electrostatic guns.
However, air assisted airless electrostatic guns do not offer the exact same amount of control at the gun whilst the air spray or HVLP electrostatic guns. The reason being the fluid pattern can not be fully adjusted from very narrow to very wide without changing the tip. Also, like the airless electrostatic gun, the operator cannot feather the gun. This may be problematic when spraying very complex substrates where in actuality the operator needs that type of control at the gun. Tip plugging may also be a concern with some aggregate filled materials.
The absolute most efficient manual electrostatic spray gun is really a portable rotary atomizer. These guns use centrifugal forces and a very good voltage electrostatic field to atomize the material. Since there is no atomizing air the paint particles travel very slowly through the electrostatic field. The result is very good transfer efficiency. However, the gun puts out a doughnut shaped spray pattern which does not work well for many production finishing applications and is employed mostly for the on-site refinishing industry.