Single product
Prove the reject path and confirmation with each limiting pack format.
Reject handling and confirmation
Packaging conveyor reject handling and confirmation guide.
Control the complete path from inspection result to confirmed product removal. This guide covers reject methods, tracking, confirmation, fault response, product presentation and acceptance evidence.
Direct answer
A packaging conveyor reject system must remove the correct product, confirm the outcome and control what happens if rejection is not proven.
The mechanical device is only one part of the system. Reliable reject handling also needs product identification, tracking from the inspection point, a stable reject window, a suitable destination, confirmation that the product left the good-product route and a defined response to a full bin, blocked chute or failed reject.
The reject method should match the pack mass, shape, stability, surface sensitivity, line speed, product pitch and available space. Air blast, pusher, diverter, drop-flap and transfer arrangements each create different product and guarding implications, so selection should be based on representative packs and the actual line sequence rather than on the actuator alone.
System boundary
Separate detection, decision, tracking, actuation and confirmation.
An inspection device or checkweigher creates the result. The conveyor and controls must then associate that result with the same physical pack until it reaches the reject point. If products can bunch, slip, rotate, be removed manually or enter from another route, a simple time delay may no longer identify the correct item.
Define which controller owns the result, tracking register, reject command, actuator, confirmation signal and fault response. The controls and interlocks guide provides a wider machine-handshake framework.
Mechanical selection
Choose the reject method around product behaviour and the required destination.
The following comparison explains the principal engineering questions. It does not approve a method without a product trial and completed risk assessment.
| Reject principle | Useful starting point | Evidence to confirm |
|---|---|---|
| Air blast | Relatively light, stable products where non-contact lateral displacement is practical. | Product mass and drag, orientation, pitch, air effect on adjacent packs and collection containment. |
| Pusher or sweep arm | Rigid packs that can accept controlled side contact. | Contact zone, stroke, return time, product stability, guide opening and guarding. |
| Diverter or lane change | Products that should remain supported while moving to an alternative route. | Guide transition, available length, speed match, destination capacity and recovery after blockage. |
| Drop flap or retracting support | Products that can safely leave the conveying surface into a controlled receptacle. | Product impact, orientation, aperture, flap cycle, containment and access. |
| Stop-and-remove or controlled hold | Low-rate or sensitive applications where automatic ejection is unsuitable. | Safe stop state, operator task, restart permission, traceability and line impact. |
Product presentation
A reject device cannot compensate for uncontrolled product pitch or unstable presentation.
The product must arrive inside the defined actuation window with enough separation from adjacent good packs. If accumulation can reach the reject zone, or if an upstream speed change alters pitch, the system needs a control response that protects product identity. Side guides should support the pack without obstructing the reject path.
Where the same conveyor also supports coding, vision inspection or checkweighing, review the complete sequence from trigger to result and then to reject confirmation. See the checkweigher integration guide and coding and inspection conveyor page.
Acceptance sequence
Prove normal rejects, closely spaced products and every declared failure state.
Use representative accepted and rejected samples in a known sequence. Record the inspection result, tracking identity, reject command, physical outcome and confirmation signal. Then create a full-bin, blocked chute, missing confirmation and power/reset condition according to the agreed design.
Mixed sequence
Run good and reject products in known order at the minimum permitted pitch.
Failure state
Create the agreed failed-reject, blocked-destination and full-bin conditions.
Reset and restart
Confirm product disposition, fault acknowledgement and controlled release after reset.
Safety and access
Guard moving reject parts and define safe clearing before production starts.
Pushers, flaps, diverters and product openings can create trapping, impact or access hazards. The completed machine risk assessment should cover the reject mechanism, receptacle access, interlocked guards where required, isolation, stored energy and the operator task for clearing a jam or emptying the destination.
The UK Health and Safety Executive advises that machinery maintenance and intervention should be planned and performed safely, including suitable isolation where necessary. See its machinery maintenance guidance. Application-specific safeguarding remains a competent design responsibility for the completed installation.
Buyer questions
Common questions about packaging conveyor reject handling
Use these answers to define the product, control and acceptance duties before quotation.
What is reject confirmation?
Reject confirmation is evidence that the identified non-conforming product actually left the good-product route. It should be separate from the command sent to the actuator because a command alone does not prove the physical outcome.
Which reject method is best for bottles?
It depends on bottle mass, base stability, sidewall strength, closure, pitch, speed and the required collection route. A representative bottle trial should confirm that the selected method removes the target without disturbing adjacent good bottles.
Can a reject system use only a time delay?
A time relationship may be acceptable only when product pitch and speed remain controlled and there is no possibility of slip, bunching, manual removal or another pack entering the tracked position. Otherwise additional tracking or position confirmation may be needed.
What should happen after a failed reject?
The system should enter the agreed safe quality state, normally preventing unverified product from continuing. The controls schedule must define the stop, indication, product disposition, reset authority and restart sequence.
How is a reject-bin full condition handled?
The design should prevent further rejects from escaping or re-entering the good route. Depending on the application, a full or blocked destination may create an alarm and controlled stop until the condition is cleared and acknowledged.
What products are needed for a reject test?
Provide every limiting pack format plus a controlled mix of accepted and designated reject samples. The test should include the closest permitted pitch and all relevant filled, empty, labelled or closure states.
Define the reject duty
Discuss reject handlingSend the pack formats, inspection result and required failure response.
Include product samples, intended pitch, inspection equipment, available reject space, destination requirements and the action required if rejection cannot be confirmed.