Find out how simple preventative maintenance can keep your presses running at peak levels and head off costly downtime and quality issues.
By Rick Fuqua
Air that exits the FRL is distributed to parts on the press. In some cases, an incoming air line feeds a large manifold that serves as a reservoir and a distribution center for several airlines that feed multiple points on the machine. If this manifold has a drain, it is good to drain it once or twice a year. Doing so tells you whether a lot of oil and/or water are getting into the press.
Check the air system past the manifold for leaks and kinks in the air lines. Kinks in air lines can cut off air supply, which results in a slow or non-working component. For example, a squeegee may not be pushing down on the substrate at the regulated pressure until mid-stroke when a restricted air line prevents proper pressure buildup. This can lead to problems with ink deposit at the beginning of the stroke, and you’ll notice that print quality improves as the squeegee travels further and further back.
Replacing mufflers on valves isn’t a widely recognized maintenance issue. These bronze mufflers help to quiet the noise of air escaping from the air valve when the valve is actuated. When these mufflers expel air, the contaminants block or restrict the air flow over time, which in turn slows the speed at which the parts operate. These mufflers cost only a few dollars. The closer the valves are to the base of the machine, the more likely they will clog sooner. Replace them every few years.
Evaluate valves that are slow to react or make a humming noise when they attempt to switch. Humming indicates that the electromagnet is having difficulty overcoming the friction in the valve when it tries to pull in the spool. This added friction might be sludge in the valve (oil and water mixture) that is overworking the electrical solenoid. Be prepared to replace the solenoid and/or valve if you don’t attend to this problem. A cleaning of the valve may solve the problem, but some valves are not designed to be serviced. If you take the valve apart, you should use new seals when putting it back together. Repair kits are available for many valves.
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