Induction seal validation and testing
Plan peel, leak and retained-sample checks so the induction sealing window is proven before production.
Why validation matters
An induction sealer creates a heat bond between the foil liner and the container mouth. A machine setting is only useful when it works with the chosen cap, liner, material, product and line speed. Validation creates a record of the sealing window so production staff can repeat an accepted setup after changeover.
Peel, leak and retained-sample checks
| Peel check | Confirms whether the foil has bonded evenly to the container mouth after cooling. Agree what an acceptable peel looks like for the pack before production starts. |
|---|---|
| Leak check | Checks whether the sealed pack resists the handling or orientation expected in production and distribution. Choose a method suitable for the product and container. |
| Burst or pressure check | Useful only where the pack and product justify it. Define the method, limit and acceptance criteria before using it for sign-off. |
| Retained samples | Keep accepted and rejected examples from trial work with the power, speed, cap torque and liner details recorded. |
Trial conditions to record
Record the cap diameter, liner construction, container material, container height, product, fill level, cap torque guidance, conveyor speed, head height, power setting, operator, date and sample batch. Where the same line runs several SKUs, record the setting for each cap and liner combination.
Speed and diameter ranges
The supplied machine information references head options covering approximately 15–130 mm and a model-dependent speed of up to 260 containers per minute. Those figures do not replace sample testing. The practical result depends on dwell time, cap diameter, liner behaviour, bottle spacing and conveyor stability.
Frequently asked questions
What is a sealing window?
A sealing window is the range of power, conveyor speed, head height and cap/liner conditions that produces an acceptable seal without under-sealing or overheating.
Should leak testing be done on every project?
A practical leak check is useful where leakage is a product or transport risk, but the exact method should match the pack and product.
Can published speed figures replace sample trials?
No. Published speed is a model-dependent reference. Final output should be confirmed with the actual cap, liner, container and conveyor conditions.
What records should be kept after commissioning?
Keep accepted settings, sample results, cap and liner details, container material and any rejected settings so the line can be reset accurately.
Need to prove a sealing window?
Send Lancing UK your cap, liner, container and target line speed so the machine selection can be tied to practical acceptance checks.
Use accepted and rejected samples to make the setup repeatable.
For a new pack, keep at least one accepted sample and one rejected example from the trial work where practical. The useful evidence is not only that a seal passed; it is which setting passed, which setting failed and what changed between those points.
A retained setup record should include cap diameter, liner construction, container material, product, fill level, power, speed, head height, cooling time before peel, and the agreed result. Where more than one cap group is used, keep a separate line in the record for each group.
| Record field | Why it is useful later |
|---|---|
| Accepted setting | Allows repeat setup after cleaning, changeover or operator shift change. |
| Rejected setting | Shows the lower or upper limit of the sealing window rather than just the target point. |
| Sample condition | Confirms whether checks were made with representative filled packs, empty packs or mock-up samples. |