Treat detection, pack tracking, rejection and reject confirmation as one complete quality-control function.
What makes coding, inspection and rejection one complete function?
Start by defining the quality decision and the pack journey from coding or measurement to confirmed reject. The layout must maintain suitable orientation, spacing and stability. The controls must associate the result with the correct pack and define the line response to a failure, missed read, device fault or reject confirmation error.
Inspection is not complete when a sensor detects a fault. The rejected item must be controlled, accounted for and prevented from rejoining accepted production.
Where should a coder or inspection device sit?
Position the device where the required surface or product condition is stable, accessible and representative of the final pack. A code may need a dry, stationary or consistently moving surface; a seal check must occur after the seal is formed; a label check must occur after application; and a final weight check must be placed where downstream additions are understood.
Allow safe access for setup, cleaning, calibration and consumable replacement without obstructing normal product flow.
How is product spacing controlled through inspection?
Use the infeed conveyor, metering device or machine pitch to create the spacing required by the inspection and reject process. The required gap depends on sensor response, decision time, reject mechanism and pack stability. Back-pressure or product contact can make the association between result and pack unreliable.
Where a checkweigher, metal detector or vision station has dedicated conveyor requirements, its infeed and discharge should be treated as part of the inspection system rather than generic transport.
What should happen when a code or inspection result fails?
The failed pack should follow a documented reject or line-stop response appropriate to the risk and process. Define whether the pack is removed automatically, held for manual action or causes a controlled stop. Specify the response to consecutive failures, an unreadable code, missing production data and loss of communication.
- Decision rule and permitted tolerances
- Pack tracking from detection to reject point
- Reject mechanism and confirmation sensor
- Reject-bin full or access-open response
- Count reconciliation and investigation threshold
- Recovery and restart checks
How are rejects confirmed and reconciled?
Use a reject confirmation method that proves the selected pack left the accepted product path. The line should know the expected reject, detect the action and raise a defined fault if confirmation is not received. Counts should distinguish inspected, accepted, rejected and unverified packs at stated count points.
Manual removal can be used in appropriate applications, but the procedure and line state must prevent an unverified pack from continuing unnoticed.
Which data and recipe interfaces need to be agreed?
Agree the source and version of code data, inspection recipes, tolerances, user permissions, time settings and production identifiers. Decide what happens when a requested recipe is unavailable or the data source cannot be reached. Protect parameters that affect quality decisions and keep a controlled backup.
Link this design to the coding and sealing page and the line-controls guide.