RTD Sensors (resistance temperature detectors) are used in hot melt packaging systems because of their precision in sensing and proportioning temperature. They consistently maintain a temperature control stability of +/- 1-degree Fahrenheit. With the ever-increasing price of adhesive, it is important that RTD sensors are used in all of Universal Systems’ hot melt hoses and glue applicators for steady adhesive application. When combined with USSE’s patented AccuScan™ solid-state control system, RTD sensors provide precise bead uniformity for all of our ProBilt™ applicators.
Since RTD sensors are so key to the adhesive application process, it is important to check them first whenever you notice glue inconsistencies. If you see that your glue bead is not sticking properly or getting clogged, it could be caused by inconsistent glue temperature. There are several causes of inconsistent glue temperature. For example, if your tank operators are opening the cover to add glue, that will cause a temperature change. RTDs control that process, by notifying the heater to turn on and run longer when those situations occur. If your RTD is weak, then the heater will not be able to maintain steady temperature. It is the easiest, most overlooked and one of the least expensive components in your application process, but is worth it’s weight in glue!
When it comes to understanding the components that make up your adhesive application system, we believe that knowledge is power. So, if you have any questions, or think that you may be having issues with your RTD sensor, do not hesitate to call Universal Systems at (800) 848-5018 to speak with one of our technicians. We can walk your line operator through testing RTD sensors and how to switch them out correctly and safely.
There are a couple different types of filters that you need to change out regularly on your adhesive melter system. One is a tank filter, which we describe in a previous article: The Importance of Tank Filters. The second, is the in-line gun filter. This is the filter that goes between the hot melt gun applicator and heated hose. This is the last line of defense against char being transferred through the module and potentially clogging the nozzle.
There are a three different in-line filter assemblies that are available for your hot melt system: Straight, 45 Degree & 90 Degree. The first is a filter assembly with a straight connector from the gun to the hose. This straight fitting is used when guns line up directly with hoses, typically applying the glue straight out to onto the boxes. The other two filter assemblies offer a 45 degree and 90 degree fitting that allows you to connect the hose to the gun at an angle. These filter assemblies are mostly used on setups where the applicator guns are either above or below the packaging line.
Each filter assembly is available with 50 mesh, 100 mesh and 200 mesh filters. The replacement filters are sold separately in packs of 5 for easy installation so that you do not need to switch out the entire assembly. The filter is easily screwed into the top of the filter body as seen below. Please make sure that you lubricate the o-rings before installation to help you for future filter changes.
For more information on which in-line filter assembly is best for you, please call (561) 272-5442 or email firstname.lastname@example.org.
Understanding hot melt tank systems is no simple task. It usually takes years of experience to learn how to effectively manage adhesive systems and keep your packaging line running efficiently and effectively. Universal Systems SE understands that new line operators come into work and might need help learning which items to replace and how to replace them the correct way. That is why we offer technical support to all of our ProBilt™ customers!
There are several maintenance tasks that we recommend be completed on a regular basis to keep your adhesive system free of char and debris, which is the number one culprit in bringing down a line. Below is an easy maintenance checklist that each line operator should have in hand.
We recommend that you print this checklist out and give it to every shift that operates the packaging line. Keep in mind that changing out items such as gun heads, modules, filters and pumps all require you to clear the old lines and remove the air pressure before re-installation. Releasing the air pressure and removing all old adhesive will ensure that all seals stay intact and reduces the char transferred from the old to the new parts.
If you need help changing out parts or have questions about which items need to be changed regularly, please call (561) 272-5442 or email email@example.com.
Since Universal Systems SE offers technical support for all of our customers, we get several calls per day with all different kinds of technical issues that line operators experience. Because many packaging lines run 24/7, without regular maintenance of key products there will always be issues after a certain period of time. As always, we recommend changing your filters, nozzles and modules when needed to eliminate any potential issues. However, there may be other parts on your packaging lines causing these issues.
For example, if you are experiencing a dripping or not fully functional module, it is most likely not an issue with the module itself. Especially since all products go through a vigorous quality control process before leaving our facility. Because the modules are air open and spring close, there are a few items to check before switching out the module. First, Universal Systems SE recommends that you check the solenoid valve. The solenoid valve is the air supply that runs into the applicator gun and fires the glue onto the box. If the solenoid valve fails, it will not generate air power to fully open the module. If the solenoid valve is weak, it will not fully exhaust all of the air out of the module, and the module piston will not seat properly, causing a drip. Another potential issue could be that char or debris has been transferred from the tank into the gun and has gotten stuck in the spring close. This piece of char, no matter how small it could be, can limit the spring from fully closing causing “dripping”. Spring tension on the gun module being set too low could also cause “dripping”, so make sure you try to adjust that before switching out modules. Finally, if the line operator has not gone through the correct steps to change out the module, the module could be compromised. The line operator needs to make sure that they lower the air pressure used on the tank before switching modules. If they do not, they could potentially send glue into the air chamber of the gun when removing the old module.
Another common technical issue is that the heated hoses are either not heating or not heating to the correct temperature. The first step is to check and ensure that the hose zone is not set to “off”. If it is, turn the hose zone to “on”. Then, you should check to make sure all connectors are securely tightened and the controller settings are correct. If all of those are working, you next need to check the ohms reading on the hose heater and hose RTD, and all of the board fuses. A USSE technical support representative can walk you through this check process and help identify the real issue.
For more information or if you need technical support not mentioned, please call (561) 272-5442 or email firstname.lastname@example.org
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 email@example.com.
One of the most common issues that many packaging line operators experience with their adhesive melter is stringing. Stringing is when the adhesive is applied to the box, but before the flaps are closed on the cartoner, the glue starts to dry and string like cotton candy floating through the air.
There are a couple of fixes for this issue. Whether you are using a straight, right angle or swirl pattern nozzle, try moving the applicator gun closer to the box flap where you are applying the adhesive. The stringing could be caused because it is travelling too far of a distance from the applicator gun to the box. The shock from hitting the cooler factory air could be causing it to lose viscosity and start drying before it even hits the box. Not only will that cause stringing, that might also compromise the integrity of the glue hold on your product packaging.
Another cause of stringing glue could be temperature. Every adhesive is different and each one might require a different melt temperature. In order to keep the adhesive a consistent viscosity, make sure that the temperature on your glue tank and applicator guns are set correctly per the adhesive requirements. If the adhesive is too viscous then you might need to increase the tank temperature or change to an adhesive with a lower viscosity. If your tank temperature is correct, but your guns are not hot enough, then the glue could start to cool while travelling from the tank to the applicator gun. In this scenario, you would see that the thickness of the glue as it leaves the nozzle. Some line operators might try fixing the issue by putting a larger diameter nozzle on the module, which could be a temporary fix, but the real issue could be the temperature setting on the gun. Simply increase the gun temperature as needed to ensure a smooth, consistent adhesive flow.
There could also be an issue with the adhesive you are using on your packaging line. Like many products, if the adhesive is too old, has been sitting for too long, or has been heated and cooled too many times, this could cause stringing. We recommend that you drain all old adhesive from your tank, clean the tank with a cleaner such as Purge Plus™, and refill with fresh adhesive.
Universal Systems SE recommends trying to correct stringing if it is happening to your packaging line. Some line operators may think it is not that big of an issue, or they might blame the adhesive manufacturers, when in fact it could be a simple and important fix.
For more information or technical support to help you better understand how to fix your stringing glue, please call Universal Systems SE at (561) 272-5442 or email firstname.lastname@example.org.
One of the most common customer service calls we receive has to do with adhesives that get mixed together and then create a mess inside the melter tank. It is important for any packaging line operator to understand that not all glue is made equal, which means they might not mix well together. Especially when operating at high heat with high demand.
Know Your Adhesive
There are two main types of adhesives that you could be using in your tank: ethylene-vinyl acetate (EVA) and polyolefin. EVA is a copolymer adhesive, most commonly used in the paper, packaging, and assembly industries, as they bond to a variety of cellulosic materials and have a wide range of formulation. Polyolefin is used mostly at low application temperatures and works best in spray or film form. The best thing to do is keep the adhesive information so that you do not accidentally order the wrong type of adhesive and mix them together. When EVA and PVA are mixed together and heated, they create a thick gelatin formulation that will destroy your melter pot. This is not something that can be cleaned out, even with the strongest of cleaners.
Clean & Purge Your Tank
It is imperative, whenever starting a new batch of adhesive to thoroughly purge and clean your tank, hoses and guns. Removing all remanence of previous adhesive build up. This will prevent any clogs or char from filtering through your adhesive system and causing any unnecessary adhesive mixing. Universal Systems offers a cleaner called Purge Plus™ that, when heated to the correct temperature within your tank, will remove all of the old adhesive and char.
For more information on Universal Systems SE or our Purge Plus™ cleaner, please contact us at (800) 848-5018 or email us at email@example.com.
One of the most dangerous, yet inevitable, occurrences running hot melt systems in your packaging lines is char. Universal Systems SE has updated technology running in our ClearFlow™ hoses that reduces char, however the main char that runs through the hoses comes from the tank itself. Once your tank is infested with char, no matter how efficiently your hoses and guns run, there is always the potential to transfer this char onto your packages. You also run the risk of char clogging your nozzles and modules, which can back up through your guns and kill your pumps. Our Universal Systems SE technicians have seen it all. That is why we have created a list of preventative tips that each line operator should follow to effectively reduce char and keep your ProBilt® system running at top capacity.
Universal Systems Se recommends a complete hot melt system cleaning at least twice a year using our Purge Plus™ system cleaner.
Hot melt adhesive should always be stored in a strong container such as a heavy-duty plastic waste container. Do not set boxes or open bags of adhesive on the floor or on the top of the container. The container should be labeled “Adhesive Only” and include your adhesive part number.
Low Quality Adhesive
With hot melt adhesives, higher price usually means higher quality, the opposite is also true. Adhesive manufacturing is a highly un-regulated industry and many companies use low cost waxes and fillers in their products to reduce cost. These products tend to burn quickly. Due to the fillers and heavy waxes, low cost adhesives can greatly reduce your adhesive mileage whereas high quality adhesives are lighter and have a lower specific gravity. The bottom line is a higher dollar per pound does not necessarily translate to higher packaging costs. We also recommend that you do not mix old adhesives with new brand adhesives. Please read our past blog to help you understand why.
Hot melt systems are not cheap, so most of the ones in operation today have been on their packaging lines for 10 – 20 years, whether they are running properly or not. That means that most likely, these older machines have char built up in their tanks. It may be time to evaluate the performance and efficiency of your aging equipment and trade up to a new ProBilt®.
To get the latest pricing on ClearFlow™ hoses, Purge Plus™ system cleaner or ProBilt® adhesive melters, please email firstname.lastname@example.org. If you are experiencing issues with char, please feel free to call one of our technicians at (800) 848-5018 and we would be happy to help you.
Hot melt machines are an important investment into the efficiency of your packaging line. Just like any important investment, you want to make sure that you are maintaining your hot melt machines to limit downtime and minimize expenses.
Below are the top 10 maintenance recommendations to ensure you get the most out of your Universal Systems machine.
1) Replace Melter Filter after 500 Hours
2) Clean Melter Tank with Purge Plus™ after 1,000 Hours
3) Clean and Flush Pump after 2,500 Hours
4) Replace Pump after 5,000 Hours
5) Replace Hose only when it stops heating
6) Replace In-Line Filters after 150 Hours
7) Replace Gun Head only when it stops heating
8) Change Module Every 1,000 Hours
9) Replace Nozzle Every 120 Hours
10) Depending on how many lines you are running, make sure you keep enough spares of each in stock.
Universal Systems SE stocks all of the above and can ship almost anything same day. For more information on how to operate your hot melt systems or perform maintenance on your system, please check out our YouTube channel.
For pricing on any items, please reach out to one of our sales representatives at email@example.com or feel free to call our corporate office at 1-800-848-5018.
There are two methods of manufacturing cartridge heaters to ensure a useful life and not have them fail prematurely. The first is a standard cartridge heater and the second is a swaged cartridge heater. Even though both cartridge heaters might look identical on the outside, they are constructed very differently. Standard cartridge heaters are the most commonly used, but if you need to operate at higher temperatures and vibration applications, then you will need a swagged cartridge heater.
A standard cartridge heater has nichrome wire heater coils that are weaved through holes in the ceramic tubing. Pure magnesium oxide filler is vibrated into the holes, heating the coils to allow maximum heat transfer to the stainless-steel sheath.
A swaged cartridge heater’s nichrome wire is wound tightly around a ceramic core, to situate it in close proximity to the heater sheath. Pure magnesium oxide is vibrated in and the heater is swaged to a specific diameter. This compresses the magnesium oxide so it becomes an improved conductor of heat from the wire while maintaining its dielectric properties. This is why it works so well with high temperatures.
The useful life of a cartridge heating element is determined by how quickly the heat generated in the resistance wire can be dissipated to the outside sheath. So why do cartridge heaters fail and sometimes prematurely? The reasons include improper fit, moisture, watt density is too high or if you are using the incorrect voltage.
Improper fit is the most common cause of cartridge heater failure. If the cartridge does not fit into the hole it is inserted, then the heater cannot dissipate the heat being generated by contact with the sheath. So, in effect, the temperature inside the heater will continue to rise until the magnesium oxide or resistance wire breaks down and the heater fails.
If moisture or impurities are present they can be drawn into the heater. Because magnesium oxide is hydroscopic, every time power to electric heaters is eliminated, an internal vacuum occurs which draws in air from the surrounding area. This vacuum can cause a short circuit.
Finally, make sure that the wattage density isn’t too high and that you are using the correct voltage. Either of these issues can a cartridge heater to fail.
If you have any other questions about your cartridge heaters, please call us at (561) 272-5442 and one of our technicians can help you diagnose any cartridge heater problems.