A typical marking system is made up of three main components; a marking gun, pressure cup/tank, and controls. While a basic system works for many different types of spray media, some have solid particles that must be kept in suspension to spray consistent marks. One solution to do this is an agitator on the pressure tank. While this thoroughly mixes the media in a tank, if it lingers in the material lines, there is potential for separation to occur there. This is where a recirculation coating system excels.
A recirculation coating system does exactly what it sounds like. It recirculates the spray media through the material lines to ensure that it never stagnates in the line. This maintains the solid particles in suspension through the liquid media and provides more consistent marks. This is typically done with a recirculation pump connected to the marking system.
The pump moves the material from the pressure tank to the marking gun. In order for the marking gun to work properly with a recirculation coating system, it must have a second material port designed for this feature. Out of the other material port, a material line runs back to the pressure tank. This completes the path for the material to flow when the recirculation system is active.
Once the gun is triggered, the recirculation pump shuts off and material flows from the tank through the gun as a typical system flows. Because the recirculation pump is not energized when the spray gun is triggered, there is no pattern pulsing that is typically seen in systems that use a diaphragm pump. You get the benefits of a recirculation coating system without the quality drawback from a diaphragm pump.
Using spray media that contain solid particles in a spray system has many benefits, but proper material agitation must be taken into account when designing a system. Our advanced marking systems offer recirculation options will maintain circulation of media through the system to ensure proper material concentrations.
Anthony Kowalski, Systems Engineer
Coating Equipment Technology, Inc