Direct answer
A reject system must remove the correct item under every valid speed and spacing condition, confirm that removal, secure the rejected product and fail safely when air, tracking, confirmation or bin status is lost. Design it as part of the inspection system, not as an accessory.
Match the mechanism to the product
Air blast suits some light stable packs, while pushers, sweep arms, drop belts, diverters or line stops suit other weights and shapes. Consider fragility, centre of gravity, speed and the risk of a rejected item rebounding into the good stream.
Prove the full size and weight range, including consecutive rejects.
Maintain product identity through tracking
Use product detection, encoder or controlled pitch so the inspection result remains linked to the correct pack. Accumulation, slip, manual removal or a line stop can disrupt timing-based tracking.
Define how tracking is reset after a jam or restart.
Confirm removal and secure the reject
A sensor should confirm the reject event where required, and the reject container should prevent easy return to saleable product. Monitor bin full, bin missing or access open.
Use a fail-safe response when the system cannot prove removal or containment.
Challenge the complete fault response
Test low air, actuator fault, sensor blockage, full bin, failed confirmation, power loss and downstream stop. Record whether the line stops, alarms, holds product or enters a controlled state.
Repeat tests at minimum spacing and maximum validated speed.
Information to prepare
- Pack weight, dimensions and fragility range
- Line speed and minimum spacing
- Inspection-to-reject tracking method
- Reject mechanism and containment
- Confirmation and bin-status sensors
- Failure responses and restart logic
- Challenge-test and maintenance plan
Packaging Conveyors
Conveyors, transfers and controlled product handling around packaging inspection.