Using an electromagnetic field to heat a foil liner so its heat-seal layer bonds to the container rim.
Also called: induction cap sealing; foil sealing; induction inner seal.
What actually bonds to the bottle during induction sealing?
The induction field heats the foil, and that heat activates a compatible sealing layer against the bottle rim. The foil and polymer sealing layer have different roles; this is not a bare aluminium disc bonding to any bottle material.
For conventional capped bottles, capping precedes induction exposure and provides contact between liner and rim. The container, closure and liner construction belong in the specification together. A foil-containing component alone does not establish compatibility with a particular bottle resin or product.
Power rating alone does not establish a successful seal. Head design, cap geometry, line speed, material pairing and product are part of the application. Incorrect sealing faces, inadequate contact, an uneven sealing land or contamination are separate concerns that increasing energy does not automatically correct.
Record the package components, head arrangement and line conditions with each trial. Assess bond coverage, leakage and opening behaviour according to the required outcome; observing foil presence checks a different feature.