Packaging change control
How do you qualify a new cap or bottle batch?
Qualify a new cap or bottle batch by comparing it with retained approved components, checking visible and functional differences, running representative filled samples through the recorded machine format, measuring the agreed closure results and observing a sustained run. Record the supplier batch and evidence so later faults can be separated from machine wear or setup drift.
Qualification starting point
Compare new components with retained approved references
Use the sequence below to compare a new component batch with retained approved references under the recorded machine format. Keep packaging identity and test conditions traceable before deciding whether an adjustment or supplier investigation is required.
Do not change several machine settings merely to make an uncontrolled packaging batch run. First establish whether the new bottle or cap differs in dimensions, finish, thread behaviour, liner condition or handling stability, then run a documented comparison using representative filled packs.
Treat packaging variation as part of machine performance
Nominal cap diameter and bottle volume do not describe every feature that affects capping. Thread form, neck finish, cap stiffness, ribs, liner, tamper band, bottle rigidity, mould variation and surface finish can alter feeding, pre-threading, belt grip and final removal torque. A supplier may remain within its own drawing while the combined pack behaves differently at the edge of the approved process window.
Use a controlled qualification sequence
- Identify the new cap and bottle batch and retain unprocessed samples.
- Compare visible condition, key fit features and supplier documentation with the approved reference.
- Use the recorded machine format rather than creating a new setting immediately.
- Run empty and representative filled bottles where fill weight or residue affects handling.
- Inspect cap presentation, bottle stability, cap height, visual finish and thread start.
- Apply the agreed torque and closure-integrity checks at the defined times.
- Run long enough to include normal feeder replenishment and line interaction.
- Approve, adjust under controlled change, or escalate the batch with the evidence retained.
Record the comparison
| Evidence | Approved reference | New batch |
|---|---|---|
| Cap and bottle identity | Supplier, component and retained batch | Supplier, component and new batch |
| Feed and presentation | Stable orientation and handover | Observed bridges, doubles, inversion or delay |
| Bottle handling | Accepted belt and guide behaviour | Slip, squeeze, rotation or cosmetic contact |
| Finished-pack checks | Approved height, visual, torque and integrity result | Same method and timing applied to new samples |
| Production run | Known stable format record | Accepted output and cause-coded faults |
Do not adjust around a component defect
If a new batch creates repeatable thread, liner, dimensional or surface faults, increasing machine pressure or widening inspection limits can mask the issue rather than control it. Preserve examples and involve the packaging supplier and machine specialist using the same evidence.
Related guidance
Continue the investigation or specification
Bottle and cap compatibility
Compare thread, liner, bottle stability and closure features.
Sample preparation
Prepare traceable empty, filled, approved and fault samples.
Cap torque test method
Apply the same measurement and integrity method to both batches.
Discuss a packaging change trial
Send retained references and the proposed new components.