FAQs
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
Leakers Occurring In the Same Location
- 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
- 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
- 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)
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)
Pinholing
- PROBABLE CAUSES:
- Excessive exposure time (low conveyor speed)
- 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:
- Wax not completely absorbed into pulpboard
- Retorquing too soon after induction sealing
Still need help with your sealing issue? Download the troubleshooting form and return to our technical services department.
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