Metal-detection line engineering
Turn a detection signal into dependable removal.
The detector identifies the event; the conveyor and reject controls must remove the correct product. We define the distance between the detector and reject point, sensor positions, conveyor speed and timing so the contaminated pack remains traceable throughout that journey.
Pack flow matters. Products must pass through the detector aperture and onward to the reject point without changing order, bridging or accumulating. Guides and transfers are configured to stabilise products while respecting the detector supplier's installation instructions.
Pusher, air-blast or downward rejection?
A pneumatic pusher can remove stable packs across the belt into a side bin. An air-blast reject can rapidly move light products without a mechanical arm in the product stream. Drop-flap and retracting-belt systems create a positive downward reject route where pack behaviour and line geometry suit them.
The right method is determined by product mass, dimensions, stability, belt width, speed, pitch, available space and the required containment. Product testing is used to establish a repeatable operating window and prevent good product from following the reject.
Fail-safe reject monitoring and secure bins
An independent reject-confirmation sensor can prove that the identified product entered the reject route. The station may also monitor air pressure, actuator position, bin presence, bin capacity and access to a lockable enclosure. Missing confirmation can trigger the alarm or controlled line-stop response agreed for the application.
For a retrofit, we review the existing detector, line controls, services, guarding, access and conveyor construction. The detector manufacturer remains the authority for its own aperture, metal-free-zone, mounting, earthing and validation requirements.
Typical metal detection applications
- Food and beverage packs
- Cartons, pouches, tubs and trays
- Bagged and wrapped products
- Existing detector retrofits
- Secure or lockable reject bins
- Verified contaminant rejection
Metal detector reject conveyor FAQs
How does a metal detector reject conveyor work?+
When the detector identifies a contaminated product, the control system tracks that pack to a timed reject mechanism. The product is removed into a controlled reject area and an independent sensor can confirm the event.
Which reject mechanism can be used with a conveyor metal detector?+
Common options include pneumatic pushers, air blast, drop flap and retracting belt systems. Product weight, stability, pitch, line speed and available space determine the suitable method.
What fail-safe monitoring is available?+
Options include reject confirmation, air-pressure monitoring, actuator position, bin-present sensing, full-bin sensing and access monitoring, with an agreed alarm or line-stop response.
Can a reject conveyor be integrated with an existing metal detector?+
Often, yes, subject to a survey of detector requirements, available conveyor length, product flow, interface signals, guarding, containment and the detector supplier's metal-free-zone and installation instructions.