TL;DR
A glue blockage stops labeling. Check the glue tank level and temperature first, then trace the supply path from tank to drum for solidified glue.
What you might see
- glue not reaching the glue drum or application roller
- label not sticking to container
- glue pump running but no flow indication
- cold glue tank temperature above setpoint
Likely causes
Solidified glue in a supply line or nozzle from a temperature drop
Glue tank heater failure allowing the glue to solidify
Glue pump filter blocked with paper or glue skin
Glue type changed to an incompatible viscosity grade
Required tools
- IR thermometer
- Heat-resistant gloves
- Approved glue line cleaning solvent
- LOTO kit
- Cleaning brushes
Safety first
- Hot melt glue operates above 150 degrees C. Splashed or dripped glue causes severe burns. Wear heat-resistant gloves and face protection at all times near the glue system.
- Lock out the glue pump and heat system before opening any supply line connection.
Procedure
- 1
Check the glue tank level. Low level can allow air into the pump causing a vapor lock.
- 2
Verify the glue tank heater is at the correct setpoint and the actual temperature is within 5 degrees C of setpoint.
Warning: Hot melt glue is at high temperature. Wear heat-resistant gloves and face protection when working near the glue tank or supply lines. - 3
Check the glue supply line from the tank to the pump for cold spots using an IR thermometer. A cold section indicates a blockage or a failed heat trace.[1]
- 4
Lock out the glue system and allow it to cool if a line disassembly is needed. Do not disconnect hot melt lines while under pressure or temperature.[1]
- 5
Remove and clean the glue pump inlet filter. Rinse with the approved solvent for the glue type.
- 6
If a line is blocked with solidified glue, apply external heat (heat gun) gently to the blocked section while maintaining glue tank temperature.
- 7
After clearing the blockage, prime the pump and confirm glue flow at the drum before restarting production.
Sources
Krones Krones Contiroll / Solomatic Labeler / Cartoner general technical documentation, Krones
Krones Contiroll / Solomatic labeler general glue system maintenance and blockage procedures (general)
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Stop fixing the same fault twice.
Dovient turns guides like this into your team's shared playbook, with AI that catches recurring issues before they break the line.