How Dirty Air Impacts Your Pneumatic Systems
Pneumatic hot melt systems are run by air in both the pump and the applicator guns. One of the most important ways to ensure the longest run time out of any pneumatic system is to make sure that the air is clean and dry. That can be easier said than done. Most all packaging facilities have oil, water, or debris in their air. That is just the way it is. Some factories will install air cleaning systems and then add lubricators to lines to ensure that other equipment that requires oil runs smoothly. But even with the most expensive and elaborate air filtration system, there will always be some type of substance that gets by and can lead to issues in the pneumatic pumps of hot melt units. The simplest solution is to install an oil removal filter regulator to the air line running to the pump.
Oily air is our most commonly found issue inside facilities that have pumps stop up. The reason is because the shifters are manufactured with very specific tolerance clearance between the shifter spool and sleeve. This design is a necessity in order to get the pump to shift. Too much clearance and the air will just blow by the spool, never building up enough air pressure to pump. Too little clearance and the shifter will jam. That being said, if you have oily air or dirty air being run through the shifter, over time, that will cause a film to build up inside the shifter and cause a jam. Depending on the amount of oil or dirt in your air, and the number of hours the systems is run for, will determine how long this will take to happen. However, if you feel like your facility air is questionable, we suggest that you use the oil-removal filter regulator to prevent any shifter stop ups.
Another pump issue that can be caused by dirty or oily air is that it can get into the air motor and damage the rulon seals. The seals need to be tight to snuggly move up and down the air motor and if they get damaged by oil or dirt, that can lead to your pump not efficiently pumping. These seals can be replaced over time and should be checked every 2,000 hours.
Universal Systems offers pump rebuild kits for the seals, as well as sells the shifter valves in case you ever run into a pump issue caused by dirty, oily air. For more information on our pump rebuilding services, or for any technical support you might need, please call (561) 272-5542 or email sales@ussefl.com.
Under Pressure: How changing air pressure impacts your hot glue lines
Universal Systems manufactures pneumatic hot melt systems, which means that our equipment operates via air pressure. It is important to understand how air pressure can put stress on equipment and why the correct pressure points are essential to run a consistent, well-maintained hot melt system.
The way that a pneumatic hot melt system works is that an airline goes into the pump, to move the pump shifter, air motor and pump piston up and down to pump the glue from the tank, through the manifold, through the hoses, into the guns and onto the boxes. There is also going to be another air line into the guns to get the module pistons to open, apply the glue, and in some cases there will be an additional air line the air to close the pistons.
Let’s start with the air pressure to the pump. The air pressure to the pump is very important and should always be set between 20 psi – 40 psi, with an ideal setting in the middle at 30 psi. If your technician thinks the pump is running too fast and lowers the psi to under 20, then the pump might not have enough pressure to move the shifter. In most cases, a pump will run at as low as 18 psi. If your technician comes to you and states that the pump was running too slow, so they increased the air pressure to over 40 psi, that could cause damage to the seals inside the pump’s air motor. It is important to note that if the air pressure on the pump is set to 40 and the pump is still not pumping efficiently, then there is another issue at hand. Most likely there is dirty air inside the shifter or a clog in the tank filter. The air pressure should never be increased to fix other issues stopping up your pump.
The second air pressure point in your hot melt system is at the applicator gun. The air going into the gun should be set at a minimum of 60 psi. In most cases, 60 is the perfect setting for the guns. If your technician tells you they need to set the psi higher to get the guns to fire, then there is a clog in the in-line filter and that filter should be replaced. If the psi to the guns is anything higher than 80, you could blow a seal on the module and have issues with application.
If you have any questions about air pressure, please call us at (561) 272-5442 or email sales@ussefl.com.