Hot Melt News

Erecting and sealing cases, cartons and boxes with hot melt adhesive is standard practice in the packaging industry. This is usually accomplished by spreading hot melt over case flaps in a series of parallel beads. Using smaller parallel beads on close centers bonds much faster than using a large bead or two. These smaller beads also offer a much stronger lamination bond, rather than the less effective point of contact bond.

T Nozzle on High Flow Manual Bead Hotmelt Handgun

“T” nozzles, or spreader nozzles, have been used as a low cost method of channeling hot melt into multiple patterns from one applicator. Hot melt adhesive flows under pressure into this “T” or spreader nozzle and is channeled into a series openings on close centers. The “T” nozzle or spreader nozzle is used with hot melt stick guns, hot melt bulk guns as well as automatic hot melt guns.

T Nozzle on ChampStick400 available from Glue Machinery Corporation

The “T” nozzle is not suitable for precise application requirements, as there can be a tendency for temperature variations within the nozzle. The “T” nozzle is much larger than a standard nozzle, so the adhesive temperature varies as it moves through the nozzle and further from the heat source. This can create poor patterning and hot melt stringing. The use of low viscosity
hot melt will result in better flow from the “T” nozzle.

Frequent and consistent use of the gun and nozzle, will also improve patterning, as the hot melt flow through the nozzle actually heats the nozzle making for more consistent temperatures from gun to substrate.

Contact Pierce Covert at 410.761.2727 to discuss this simple alternative to improving your case sealing operation. Also see: Ergo Erector Basic Case Sealer

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.