How to Configure Metal Detection in Food Production Lines: Selection and Installation Points

The metal detection stage is usually placed after final packaging and before shipment, while incoming materials and key processing points can also be checked online or by sampling. Before configuration, clarify product characteristics: products with high moisture, salt content or aluminum foil packaging are easily affected by product effect in conventional balanced-coil detectors, so multi-frequency or phase-adjustment technology can be considered, and X-ray inspection is often more suitable for foil packaging. Belt width, aperture height and line speed should match the equipment capacity to avoid missed detection at excessive speed.

Equipment selection should consider the target metal types and required sensitivity. Ferrous metals are easier to detect, while stainless steel and non-ferrous metals require higher sensitivity; acceptance tests should use corresponding test pieces repeatedly under production conditions rather than only at no load. Common rejection methods include flap, pusher, air blast and belt drop, chosen according to package form and line rhythm, together with audible and visual alarms and automatic records for traceability and quality system audits.

Installation and daily maintenance also affect detection performance. The equipment should be kept away from inverters and high-power motors, and the conveyor belt should be cleaned regularly and checked for damage to avoid false alarms from metal debris. A daily start-up verification and periodic sensitivity check system with retained records is recommended. For plants running multiple products on one line, storing detection parameters as recipes can reduce changeover debugging time and help the metal detection stage integrate steadily into the quality control process.