How to Configure Metal Detection in Food Production Lines: A Practical Guide for Buyers and QC

When configuring metal detection, first decide where the detection points go. A common approach is to place inspection at raw material intake, after critical processing steps and before final packaging, while avoiding areas with strong vibration or significant temperature and humidity changes. Conveyor-type metal detectors suit bulk products and pre-packaging inspection, while pipeline systems suit sauces and slurries. Selection should consider product form, packaging material and line speed.

Equipment selection should focus on the characteristics of the product being inspected. Products with high moisture, salt content or aluminium foil packaging can produce product effect or shield the signal, so units with suitable frequency and aperture should be chosen, and X-ray inspection may be considered where needed. Aperture size should match product dimensions, conveyor speed should match line throughput, and space should be reserved for the rejection device.

Once the detection stage is running, a routine verification system should be established. Sensitivity should be tested with standard test pieces each shift, with detection and rejection results recorded, and the conveyor belt, rejection cylinder and photoelectric sensors checked regularly. Rejection can use a pusher, flap or air blast, depending on packaging and downstream processes. Parameter changes and maintenance records should be kept for traceability and quality management.