Hot Melt News

Improved efficiency is an overriding concern in today’s competitive environment.  An easy place to start is with adhesive usage.  Most automatic hot melt applications can be adjusted to operate with less hot melt adhesive. When planned and executed properly, adhesive reduction can offer significant long term cost savings.

Before making any changes to your hot melt system or adhesives, you should produce sample blanks with non-compressed hot melt and glued samples for evaluation by your hot melt adhesive and hot melt machinery suppliers.

To make thorough recommendations for your adhesive process, it is important to include the following information with your samples:

• Hot Melt System Temperatures
• Air Pressure Used for the Pump
• Nozzle Tip Orifice Size
• Adhesive Specification Sheet
• Current Consumption per Package
• Type of Hot Melt System Currently in Use
• Speed of Operation
• Frequency of Hot Melt System Maintenance
• Pattern Coverage Requirements.
  To include:
  • Number of Beads
  • Bead Profile
  • Centers Between the Beads

It can also be helpful to have your engineering, maintenance, and production personnel review these same samples. They are often able to provide valuable insight into your adhesive application and consumption process.

Too often, hot melt adhesive is used to compensate for other deficiencies in the production process. Dirty and/or poorly maintained hot melt systems can result in reduced adhesive bond quality. Nozzle cloggage issues can merely be the result of an incorrect orifice size on the nozzles. Another point to consider with regard to potential adhesive waste is hot melt application temperature.If the temperature is too hot, the adhesive is too thin, and this can result in excess amounts of adhesive being dispensed.

The case, carton, corrugated box sealing and erecting industry is one that has seen significant improvements on adhesive savings with the use of professional and in-house adhesive consumption consultation. It is important to note that incorrect compression of the adhesive and substrate on the erector or sealer can affect the sealing capacity of hot melts between substrates.

Be sure to also read our article, “Use Lower Cost Hot Melt” to learn about the benefits of using “Melt on Demand” Hot Melt Tanks and how they too can reduce your production costs.

Contact Glue Machinery Corporation today to discuss your application and how we can improve your adhesive savings.

Nordson Corporation®* offers quality hot melt machinery and components to manufacturing companies worldwide.

For many years, Nordson®competitors have offered /second rate/low quality/ replacement hoses, guns, and nozzles to retrofit Nordson® tanks. These components, while not offering the performance of the Nordson® parts, were often purchased because of their lower sales price.

Many Nordson® hot melt equipment customers have realized that production losses due to lesser performance replacement components is not worth the up front savings on these components and have returned to purchasing the Nordson® manufactured components.

This industry shift back to original Nordson® hot melt equipment components has forced a select few competitors producing Nordson® replacement components to dramatically improve component quality.

Lower cost quality Nordson® compatible tanks, hoses, guns, modules and nozzles are are now available and provide long operational life at much lower prices.

Some of the key features to look for are as follow:

1. Does the company supplying Nordson® hot melt parts offer a complete Nordson replacement system that is compatible with your current Nordson® hot melt system?
2. Do the Nordson® replacement parts retrofit directly to the Nordson® systems in your plant?
3. Are the Nordson® replacement parts built to similar or exact Nordson® specifications and do they offer the same warranties?

The highest quality replacement parts that operate with Nordson® systems typically offer a 25% to 30% savings over comparable Nordson® equipment. Be wary of  components priced at even greater savings, as this is typically an indication of lower quality.

Call Glue Machinery Corporation® to discuss your system parts and component needs with an experienced manufacturer and supplier of quality Nordson® replacement parts. Contact Pierce Covert at 1-888-202-2468 or email info@gluemachinery.com

Nordson® is a registered trademark of Nordson Corporation and is not affiliated with Glue Machinery Corporation.

Heated hoses are used to convey hot melt (thermoplastic) adhesives in the typical adhesive application system from the melt tank to the dispensing valves. The hoses are temperature controlled by means of a sensor, located on the outside of the hose core, usually between the hose heater and the hose outer wall. Remote temperature controls are capable of holding temperatures fairly close to the setpoints today, as compared to years ago.

There is still a problem with contamination over time within the hose itself, despite manufacturer’s efforts to minimize this tendency. Some adhesives can virtually eliminate charring within the hose, but most of the standard hot melt adhesives today have some limit in terms of ‘pot life’. This is the length of time that a material can be held at a given temperature before signs of degradation begin to occur. This period of time can range from several hours to almost indefinitely, depending on the adhesive and its formulations. The average hot melt has a pot life of 50-100 hours at application temperature, often 350F.

The issues begin to occur within hoses that are not kept in continuous production first, but can eventually affect all hoses over time. When the material is not flowing within the hose, the hot melt that is in contact with the hose wall is the hottest material in the hose. The adhesive, over time, if exposed to high heat will eventually begin to break down, often leading to an increase in viscosity, gelling, and ultimately charring which forms over time on the hose interior walls. The use of ‘cleaning fluids’ to try and dislodge this ‘char’ often is not fully effective, rather loosening and removing some, but leaving the rest to become dislodged after the hose is put back in service.

Users can minimize problems with hoses over the long term by using the newer ‘standby’ feature on hot melt tanks which  lower the hose temperatures when not in use. Other options are to manually lower hose and gun temperatures or simply turn off the entire system to minimize periods where they are kept hot but material is not being dispensed. It is recommended to replace hot melt hoses every 3 or so years, depending on system usage and materials being used, to ensure clean system operation and minimized downtime due to clogged nozzles and filter maintenance.

Hot Melt Hose Operation by John Neu at Glue Machinery Corporation

Champ Industrial Hot Melt Guns & High Hot Melt Rate Tips

Bulk self contained hot melt handguns, such as Glue Machinery Corporations Champ Hot Melt Handguns, process hot melt in an internal reservoir located inside the gun.  This gun has very high output capability, far in excess of the guns ability to melt adhesive.

Adhesive should be regularly introduced into the gun in small quantities of less than one ounce to maximize the melt rate of this industrial equipment. A tank of molten hot melt adhesive dramatically increases the guns ability to melt hot melt and insures that the glue pattern is not affected with cooler, lower viscosity hot melt.

The Champ Guns all have adjustable temperature controls. It is important to keep the gun at or below the recommended adhesive application temperature of 350 F. The Champ 5, featuring the easily adjusted temperature dial on the back, is recommended if you need to ramp up the melt rate for short intervals.

Over-heating hot melt is counter-productive and usually causes adhesive degradation and/or charring.  Charring of the adhesive creates debris that can clog the nozzle or hold the check valve nozzle tip.

We recommend the following Hot Melt adhesive tips:

1. Reduce the temperature of the gun to suggested levels
2. Fill the gun regularly
3. Use higher quality hot melt for improved consistency, strength, and ease of application
4. Add a second gun for backup and streamlining purposes
5. Purchase a melt tank to supplement the melt rate of the guns and lower the temperature of the guns
6. Consider purchasing a larger hot melt system to include tank with pump, flexible hose, and handgun. These systems are able to handle your higher melt rate requirements

Dynamini Bulk Hot Melt Tank from Glue Machinery Corporation

In manual assembly and packaging applications, the actual hot melt adhesive usage is often twice as much as is required.  Precise manual application of hot melt can be difficult; therefore operators apply additional adhesive to insure a sufficient bond.  Packaging and/or product failures are more expensive than the cost of adhesive overuse, so managers simply accept higher adhesive consumption as a cost of doing business.

With skyrocketing raw material and shipping costs pushing the average cost of hot melt to more than $2.00 per pound, it makes sense to take another look at hot melt consumption.

Tips to Control Hot Melt Adhesive Consumption:

1. TRAINING — Operators have the ultimate control over adhesive usage.  Thorough documentation and training on approved assembly procedures will help operators gauge the correct amount of adhesive usage.
2. EVALUATION — Regular quality control checks should be performed to ensure that the appropriate amount of adhesive is being applied.  If not, additional communication and training with operators might be necessary.
3. EQUIPMENT – There are many options within adhesive application equipment.  Melting, pumping and applying capabilities of equipment should match assembly requirements.  Under-specified hot melt equipment may require operators to overheat the system in order to maintain sufficient melt rates.  This overheating can degrade adhesive and affect subsequent bonds.  In addition, this can lead to increased system maintenance requirements.
4. ADHESIVE – It is critical that the adhesive have the appropriate open time, set time and bond strength for the application.  This can only be accomplished with thorough testing.  If any characteristic of the adhesive does not match the application, consumption will certainly be affected.  Keep in mind that more adhesive does not necessarily mean a better bond; the amount of adhesive affects set times and subsequent bonds.
5. ERGONOMICS – Make it easy for operators to manipulate their tools.  Ease of operation enables operators to apply consistent patterns.
6. ASSEMBLY TIME – Operators need to have sufficient time to focus on the application.  This will allow for correct and standardized adhesive patterning on each package.
7. AUTOMATION – Consider ways to go “Hands Free.”  Benchtop units and XY Tables can provide more consistent and controlled adhesive application.

With proper training, monitoring, supplies and tools operators can produce better products, in less time with less adhesive.  Please visit www.gluemachinery.com/ergo-erector for an example of a system that has produced significant adhesive usage reductions in the case erecting industry.

Be sure to check in next month for information about reducing adhesive consumption in auto glueing applications.

Contact Pierce Covert to discuss your particular process and application needs to find out how we can improve your consumption rates.

The Dynamelt and Dynamini hot melt systems have an easily accessible hot melt filter located in the top of the hot melter manifold.

Hot melt adhesive can cause severe burns, therefore it is critical that users are very careful when operating on or with this machine. When working with this filter please remember to wear protective gloves, clothing, and glasses to prevent burns and other related dangers. It is also important to turn off both air and power to your hot melt system before servicing the filter in the hose manifold.

We suggest that you read all manuals for the Dynamini and Dynamelt prior to servicing the unit as well.

After performing the preventative and initial steps above, remove the cover plate covering the top of the hose manifold.

With an M5 Allen wrench vent the pressurized adhesive from the hose manifold as shown in the video to be shown below.

Finally, with a 5/8 wrench remove the large bolt and extract the 40 or 100 mesh filter from the hose manifold.

Dynamini/Dynamelt Filter Removal Animation on Youtube

Call or email Glue Machinery service technicians with any questions regarding the Dynamini or Dynamelt. Please note that all parts are available and often ready for immediate delivery with one call for these units.

4234 Boston St, Baltimore, Maryland 21224
Toll Free 1-888-202-2468 | Phone: 410-761-2727 | Fax: 410-761-5127 | Email: info@gluemachinery.com