A metal detector reject system must remove the correct contaminated pack and keep it securely separated from accepted production. Typical options include a pneumatic pusher, air blast, drop flap, retracting belt or stop-on-detect arrangement, combined where required with reject confirmation, air-pressure monitoring, bin-present sensing and a lockable reject bin.
Application engineering
What should a metal detector reject conveyor include?
The detector output starts the reject sequence, but dependable control also requires accurate pack tracking, a suitable rejection window and a route that prevents the failed item returning to the good-product flow. The system must remain reliable at maximum line speed and minimum product spacing.
For many rigid packaged products, a pneumatic pusher provides positive side rejection. Air blast can suit lighter packs, while a retracting belt or drop flap creates a controlled downward reject path. Stop-on-detect may be considered where automatic rejection is unsuitable or throughput is low.
Oxford Vision Systems can incorporate independent reject confirmation, reject-bin present and full sensors, pneumatic pressure monitoring and a defined alarm or controlled line stop. Stainless-steel construction and cleanable layouts are available for food and beverage environments.
Key application considerations
- Pusher, air, flap and retracting-belt options
- Detector signal and product tracking interface
- Reject confirmation sensor
- Low-air and bin-status monitoring
- Secure lockable reject containment
- Food-grade stainless-steel construction