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PROBLEM
|
PROBABLE CAUSE
|
SUGGESTED SOLUTIONS
|
|
Poor Adhesion
|
Temperature too low |
Increase temperature |
| Insufficient adhesive amount |
Increase glue line |
| Coated or difficult substrate |
Select proper adhesive |
| Poor compression |
Check temperature |
|
Pop Opens
Adhesion on
one substraight
|
Insufficient glue amount |
Increase pressure or nozzle size |
| Temperature to low |
Increase Temperature |
|
Pop Opens
Adhesion on
two substraights
|
Too much adhesive |
Decrease glue application |
| Poor Compression |
Increase compression time |
| Shifting during compression |
Correct compression |
| Temperature too high |
Decrease temperature |
| Charring |
Temperature too high |
Lower temperature in tank |
| Hot melt charring on side walls |
Keep tank filled |
| Air oxidizing hot melt |
Keep lid closed |
| Poor stability of hot melt |
Select different hot melt |
| Gelling |
Overheating |
Drain system and lower temp |
| Mixing incompatable adhesives |
Check with hot melt supplier |
| Poor stability of hot melt |
Select different hot melt |
| Smoking |
Temperature too high in tank |
Lower temperature |
| Poor stability of hot melt |
Select different hot melt |
| Hot Melt Not Flowing Evenly From All Nozzles |
Nozzle clogged |
Clean or repair nozzle |
| Remote nozzle in multiple nozzle set-up may be affected by pressuredrop |
Increase temperature or pressure slightly. Install larger nozzle orifices on remote nozzles |
|
|
| Stringing Drooling |
Teperature too low |
Increase pot temperature |
| Pressure too low |
Increase pressure |
| Nozzle too far from substrate |
Adjust nozzle |
| Poor shut off of nozzle |
Repair or replace spool valve |
| Bubbles In Hot Melt Bead On Carton Flap |
Moisture level of board too high & moisture is boiling out of board |
Check by applying hot melt to metal or other low moisture material. If no bubles, then problem is moisture. |
| Not Enough Open Time |
Not enough adhesive |
Apply more adhesive |
| Application temperature too low |
raise applicator temperature |
| Cold flaps set hot melt too quickly |
Preheat carton flaps |
| Too long before entering compression selection |
Relocate applicator closer to compression section of machine |
| Adhesive Not Penetrating Substraight |
Not enough adhesive |
Apply more adhesive |
| Application temprature too low |
Raise application temperature slightly |
| Printed surface of substrate coated with lacquer or clear ink |
Increase pressure/temperature or another hot melt may be required |
