FAQ and Troubleshooting
Top 10 Issues
- Weak or No Seal
PROBABLE CAUSES:
Too low power setting for line speed.
Removing closure too soon after induction sealing.
Air space too wide.
Induction sealing equipment off.
Wrong sealing face on liner for that type of container.
- PARTIAL SEALS | High Percentage of Leakers
PROBABLE CAUSES:
Closure having too low on torque.
Induction sealing head alignment not parallel, centered and level to closure.
Land area not level.
Product touching liner when being induction sealed.
Part of land area contaminated with product, flame treated or chemical treated.
- Partial Seals | Low Percentage of Leakers (less than 2%)
PROBABLE CAUSES:
Liner too thick or rigid for closure to apply consistent pressure on the land area.
Closure not turning a full 360°.
Container finish has saddle, ridges, flashing, parting line or narrow land area.
Closure is too large for neck of container.
Closure should be designed to have raised pressure bead to cover majority of land area to ensure consistent and complete seals.
Land area not level.
Part of land area contaminated with product, flame treated or chemical treated.
Inconsistency in required on torque.
Closure not designed to accommodate the overhang of liner.
- Do Leakers Occur in a Common Area
PROBABLE CAUSES:
Oversize liner (overhang) interfering with uniform pressure.
In unscrewed closure most times the overhang is in the same location so leakers could be at the overhang or opposite to it.
Closure not turning a full 360°.
Check both parting lines.
- Excessive Removal Torque of Closure | One-Piece Liner
PROBABLE CAUSES:
Excessive exposure time (low conveyor speed).
Too high power setting on induction equipment.
Too high on-torque.
Closure and container threads not properly matched.
Tri-Tabs sticking to side wall and threads of closure.
Liner's overhang is sticking to side wall and threads of closure.
With excessive power, the primary liner will stick to the PE secondary liner on the outside edges.
- Excessive Removal Torque of Closure | Two-Piece Liners (wax not totally absorbed)
PROBABLE CAUSES:
Product touching liner when being induction sealed.
Too high on-torque.
Insufficient exposure time (conveyor too fast).
Insufficient induction field strength (low power).
Improper coil height.
Insufficient hot melt adhesive.
Hot melt off center and squeezes up threads.
Liner disk undersized. Plastic from container finish squeezing and bonding to closure pulp backing.
- Very Little or No Removal Torques of Closure
PROBABLE CAUSES:
Excessive application torque and stripping of threads.
Excessive power setting degradation of pulp backing.
Closure applied too lightly (very little on-torque before sealing).
- Scorched or Burnt Pulp and Induction Liner
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PROBABLE CAUSES:
Induction sealing head alignment not parallel, centered and level to closure.
Excessive exposure time (low conveyor time).
Excessive power setting (field strength too high).
Bottle jamming under induction head.
Closure not fully torqued-on (no heat sink from containers and closure).
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- Foil Corrosion
PROBABLE CAUSES:
Part of land area contaminated with product, flame treated or chemical treated.
Wrong material for application.
Excessive exposure time (low conveyor speed).
Too high power setting on induction equipment.
- Back Bonding to Closure
PROBABLE CAUSES:
Melt point conflict between backing and closure.
Incorrect backing for application.
Excessive power setting (field strength too high).
All Issues
- Pinholing
PROBABLE CAUSES:
Related answers:
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Excessive exposure time (low conveyor speed).
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Part of land area contaminated with product, flame treated or chemical treated.
-
Excessive power setting (field strength too high).
- Pinwheeling Effect on Liner
PROBABLE CAUSES:
Related answers:
-
Wax not completely absorbed into pulpboard.
-
Retorquing too soon after induction sealing.
