The Lost Art of Troubleshooting
Troubleshooting is most definitely a lost art. In today’s throwaway society, we have lost touch with our ability to fix things ourselves. That is true in all aspects of business and most definitely prevalent in the packaging world.
For us, in the hot melt application industry, we have seen it get progressively worse over the last few years. Ever since the pandemic, it seems that most hot melt manufacturers no longer stand behind their equipment and help with troubleshooting. Industry giants, like Nordson, want you to buy new machines, they don’t want you to fix what you already have. Here at Universal Systems, that is the exact opposite of our company culture. We are here to help, we believe in our equipment, and that the art of troubleshooting isn’t something that should be lost forever.
That being said, troubleshooting a pump not running doesn’t mean hitting it with a wrench until it moves. There is an art to it. Using deductive thinking to pinpoint the cause of the issue versus just replacing each piece until it starts working again. For example, your line is running a multi-module gun, and the last module on the line isn’t getting glue. In order to figure out where the real issue lies you first need to make sure all of your key points are met. First, is your glue heated to the correct temperature? What is the consistency of the glue out of the first module in the gun versus the second, etc.? If the gun isn’t heated to temperature, your glue’s viscosity may not be correct to run through the manifold to all modules. Second, have you checked your in-line filters? There could be a clog in the filter not allowing enough glue to flow into the gun to get to all modules. There could also be a clog in manifold itself. Once you eliminate all potential variables, you will be able to deduct what your actual problem may be.
Training on equipment is also very important in practicing the art of troubleshooting. If you have line operators that understand how your equipment works, they will be better equipped to troubleshoot potential issues. If your line operators or floor managers are not fully versed with your equipment, you should be able to call the equipment manufacturer to go through troubleshooting steps with you. At Universal Systems, we pride ourselves in our customer service and ability to walk any customer through troubleshooting. If you have a manufacturer, like Nordson, that will not take that time with you, maybe it’s time for a change to USSE.
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.
Piston Pump Troubleshooting
There are several things that can cause a piston pump to stop working. The most common reason is that it is clogged. Unfortunately, not all line operators take the time to close the lid on a glue tank. With a lot of carton dust in the air at any facility, this dust gets into the glue pot and melts in with the glue. When the pump shifter runs to pump the glue from the pot into the hose, that carton dust gathers around the pump which can cause it to seize. The simple solution to this is to make sure that all shift line operators are diligent about closing the tank covers, that’s why they are on there.
If carton dust is not your issue, and the pump fails, below are a few other possible causes and the corresponding solutions.
- Adhesive not sufficiently heated – check the tank temperature and required melt temperature of your adhesive and set accordingly.
- Inadequate or no input air to pump – increase the air pressure from the plant air supply and see if the pump will run.
- Dry running – when a tank drops below a certain adhesive level in the pot, the pump does not have enough glue to operate at full capacity. The glue that runs through the pump acts as a padding so that the shifter does not pound against the top and bottom of the pump itself. When that padding is less, the pounding shifter can cause damage to the magnets and create an issue with the shifter. The only solution to this is to get a new shifter and potentially invest in an auto fill on-demand system that fills the glue into the tank for you, leaving less pressure on the line operators to fill the pot.
- No Tank Screen or Clogged Tank Screen – the tank screen lives at the bottom of the tank and is the first line of defense against any foreign debris getting into the pump. Sometimes the tank screen gets removed or never cleaned. That can cause debris build up and seize your pump. It is easily cleaned by lifting out of the empty tank and then cleaning the tank with Purge Plus™.
- Clogged Tank Filter – the tank filter screws into the side of the tank and filters the glue after it leaves the tank. If the tank filter is clogged, then the adhesive will back up in the pump, causing the pump to seize.
- Pump solenoid is not on – if the tank is not within 35 degrees of the setpoint temperature on the control panel, the pump solenoid will not turn on. Check the setpoint temperature and make sure it is correct. If the setpoint temperature is correct and reading properly, then it might be a failed solenoid that needs to be replaced.
If you go through all of these troubleshooting steps and still have an issue with your pump, please call (561) 272-5442 or email sales@ussefl.com.