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What is a heat induction liner?

Heat induction liners are typically made up of laminated layers. There is a pulpboard layer, a wax layer, the sealing foil, and polymer layer. After the bottle is filled, the cap (with the liner inside), is applied. The induction sealer head emits an electromagnetic field through which the container passes. This induces an electric current in the sealing foil causing very rapid heating. As the foil heats up, the polymer layer melts onto the top surface of the container creating a hermetic seal. At the same time, the wax is melted and absorbed into the pulpboard layer, releasing the foil.

When the cap is removed from the product, there is a perfect seal on top of the container and the pulpboard remains in the cap as a liner.

Does USP carry the heat induction sealers to seal the liners?
A. No, that is not something that we carry. All we offer are the heat induction seals.

What does P/AF mean?
A. Aluminum foil laminated to paper and bonded to pulboard

Why use induction cap sealing?
A. The seal provides a good oxygen barrier, improving shelf life of products
it shows tamper evidence
Avoids spillage

What container materials can be sealed?
A. Most container materials can be sealed, including

Title: What is a heat induction liner?
Description: How do you seal the Heat Induction liners and other FAQ's.
Published: 11/4/2008
Last Edited: 12/28/2022
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