Packing-line inspection
A camera does not improve the pack unless the defect, viewing position, lighting, decision rule and reject action are defined. Start with the quality risk and retained defect samples, then select the inspection method.
Buyer guidance
VFFS lines can use sensors or vision systems to check selected visible features such as print or code presence, registration position, pack dimensions, label presence and some forms of seal-area contamination. Vision does not replace dose control, destructive seal testing, leak testing or metal detection where those controls are required.
Collect accepted packs and real examples of missing code, unreadable code, registration shift, folded film, contaminated seal, skewed cut, absent label and damaged pack. Record which defects are safety-critical, quality-critical or presentation-only. A system cannot be validated against defects that have not been described and represented.
Inspection before forming can see flat printed film and registration marks; inspection after sealing can see the finished pack but may have wrinkles, reflections and movement. Some checks need more than one camera or a controlled conveyor. Ensure the chosen position allows stable presentation, consistent distance, adequate lighting and enough time to make and act on a decision.
Detecting that ink exists is different from reading the characters, checking their position or verifying them against the current job. Define whether the requirement is code presence, optical character recognition, optical character verification, barcode grading or comparison with recipe data. Each requires different setup and validation.
A failed inspection must be associated with the correct pack and removed reliably. Confirm conveyor pitch, tracking, reject confirmation, reject-bin monitoring and what happens when the reject path is unavailable. Decide whether repeated failures stop the line, raise an alarm or create a controlled hold for investigation.
Test accepted and defective samples across film colours, print batches, product fill, bag movement, lighting changes, reel joins, start-up and speed range. Record false reject and false accept findings. Changes to film artwork, code position, lighting, camera, lens, conveyor or recipe should trigger controlled review.
Images, counts and reason codes can support root-cause analysis, but retention and access should match the quality and data policy. Link the inspection result to product and film batches only where the line architecture can do so reliably. A dashboard is not a substitute for calibrated checks and approved release procedures.
Decision aid
| Inspection objective | Possible method | Important limitation |
|---|---|---|
| Printed-film registration | Registration sensor or camera before forming | Film tracking and mechanical stretch can still move the cut |
| Code presence or readability | Camera with controlled lighting and print-area presentation | Presence is not the same as correct content |
| Seal-area contamination | Camera after sealing where the seal can be presented | Some contamination or channel leaks may not be visually detectable |
| Pack dimensions or cut position | Camera or dimensional sensor on a stable conveyor | Bag movement and wrinkles must be controlled |
| Label presence and position | Vision check after label application | Transparent labels and reflective film need suitable lighting |
| Reject confirmation | Sensor at the reject path | Must prove the failed pack reached the secured reject container |
Quotation preparation
Buyer questions
Not by appearance alone. Vision can detect selected visible defects, while seal integrity may require other validated tests.
Choose a point where the code is visible, stable and consistently lit, with enough conveyor distance to reject the correct pack.
OCR reads characters; OCV compares visible characters with an expected value or pattern. The required control must be defined for the job.
Use representative accepted samples, stable product presentation, controlled lighting, documented thresholds and review after film or artwork changes.
The response depends on risk and process capability. Define alarm, reject, hold and stop rules in the quality plan.
Application review