How to Choose the Right Food Metal Detector for Your Production Line
Choosing the right metal detector for your food production line is not just about buying a machine — it's about protecting your brand, your customers, and your compliance record.
At Fanchi-tech, we recently installed a conveyor-type metal detection system for a flour and powder packaging line in Southeast Asia. The customer needed a solution that could reliably detect ferrous, non-ferrous, and stainless steel contaminants in 25kg bagged products, while integrating seamlessly with their existing checkweigher and rejector.
What to Look for in a Food Grade Metal Detector
1. Sensitivity Level
The most critical specification is not the aperture size but the smallest detectable metal sphere. A quality food metal detector should reliably detect:
- Ferrous metal: ≥1.0mm
- Non-ferrous metal: ≥1.5mm
- Stainless steel: ≥2.0mm
Our MD-series conveyor metal detectors use dual-frequency digital signal processing that maintains stable sensitivity even when the product is wet, salty, or packaged in metalized film.
2. Rejector Integration
A metal detector without a proper rejector is just a sensor. The reject system must:
- Trigger within milliseconds when contamination is detected
- Auto-eject the contaminated product without stopping the line
- Include a reject confirmation sensor to verify the product was actually removed
This is where reject timing synchronization matters — the reject arm must fire at the exact moment the contaminated product reaches it, based on belt speed and product spacing. Fanchi-tech systems auto-calibrate this timing during installation.
3. IP Rating and Washdown Design
Food production environments require frequent washdown. Look for a stainless steel (SUS304) frame, sealed conveyor belt, and a touchscreen that can withstand high-pressure cleaning.
4. Data Traceability
Every detection event should be logged: date, time, product type, metal type, and reject status. This data is essential for HACCP audits and customer quality assurance requirements.
Real-World Installation: Flour Bag Line
The installation shown above is our conveyor metal detector running on a 25kg flour bag packaging line. Key features:
- Belt conveyor with adjustable speed
- Touchscreen HMI showing real-time detection status
- Integrated reject flap with confirmation sensor
- SUS304 stainless steel frame for food grade washdown
The customer's previous detector was missing small stainless steel fragments in sealed bags — leading to customer complaints and a rejected shipment. After upgrading to Fanchi-tech, they achieved zero contamination escapes in the first 90 days of operation.
Fixed Conveyor vs. Tabletop Metal Detectors
For high-speed lines running 24/7, a fixed conveyor system integrated with the rejector is always the best investment. It maintains consistent sensitivity, synchronized reject timing, and logs every detection event automatically. Tabletop models are suitable only for low-speed, manual inspection stations.
Contact Fanchi-tech
If you're evaluating metal detectors for your food production line, we can help you choose the right model based on your product type, line speed, and packaging format.
Email: kerry@fanchitech.net
WhatsApp: +86 13917555254
Website: fanchitech.net
Post time: Nov-06-2026