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Closure Liners Explained: PS-22, F217, Induction and Vented Options
A practical guide to choosing closure liners by product compatibility, seal method, tamper evidence and repeated opening.
This guide covers closure liner selection with practical checks for product teams, packaging buyers and sourcing managers.
A cap is not a complete closure until the liner and bottle finish are considered. The liner is the part that contacts the rim, compresses and controls much of the seal.
Choosing a liner by price alone can create leakage, swollen gaskets or a difficult opening experience. The right question is how the product, filling process and customer will interact with the sealed package.
Short answer: Match the liner to the product and sealing method, not just the cap diameter. Test the actual bottle, cap, liner, torque and storage conditions as a single system.
What common liner types are used for
Pressure-sensitive and foam liners are used in many standard screw closures. Induction liners can create a sealed membrane that is peeled or pierced by the user. Vented liners are relevant where pressure equalization or airflow is needed.
Material compatibility is central. Oils, solvents, acids and aggressive ingredients can affect foam, film or adhesive layers differently. The closure supplier should know the formula exposure and storage conditions.
Seal performance depends on application
Torque and liner compression affect sealing. Too little may leak; too much can distort the closure or make it difficult to remove. Validate application settings with the filled package.
Induction sealing adds process variables such as foil structure, equipment power and cooling. A liner that passes a dry test may behave differently after filling.
Plan the opening experience
If the customer must peel a membrane, leave enough tab and space to grip it. If a liner remains in the cap, check whether it stays in place after repeated opening and closing.
Quick comparison
Use this table for early screening, then sample-test:
| Liner type | Typical purpose | Key check |
|---|---|---|
| Foam or F217-style | General sealing and repeated opening in many closures. | Product compatibility, compression and closure fit. |
| Pressure-sensitive | A supplemental seal that adheres to the bottle rim. | Adhesion, residue and whether tamper evidence is required. |
| Induction seal | Membrane seal created after filling. | Foil compatibility, equipment settings and peelability. |
| Vented liner | Pressure equalization or controlled airflow. | Vent rate, leakage direction and product contact. |
Common mistakes to avoid
- Choosing a liner only by cap diameter.
- Testing with water rather than the final formulation.
- Ignoring application torque and capping equipment.
- Assuming a liner provides tamper evidence when it does not.
Before you approve the package
- Formula contact and storage temperature.
- Bottle finish, cap material and closure depth.
- Induction, pressure-sensitive or vented requirements.
- Application torque and removal experience.
- Leak, compatibility and transport tests.
Continue with HIQ Packaging
If the specification is still open, start with the relevant product category or send the team a sample request. HIQ Packaging can help connect the container, closure, dispenser and production requirements without changing the commercial details already approved for the project.
Frequently asked questions
Does an F217 liner fit every bottle with the same cap size?
No. The bottle finish, closure and liner must match, and the product must be tested for compatibility.
Is a pressure-sensitive liner tamper-evident?
A pressure-sensitive liner can provide a supplemental seal, but it is not automatically a tamper-evident system.
When is a vented liner needed?
It may be used where pressure changes or airflow require controlled venting. The vent path and product exposure must be validated.
Further reading: FDA Food Ingredients and Packaging.