Paul: Industrial metal detection systems can identify all types of metals, including ferrous (chrome, steel, etc.), non-ferrous (brass, aluminum, etc.), and magnetic and non-magnetic stainless steels. These are available as conveyorized, vertical and gravity, and pipeline systems. Metal detection relies on differences in magnetic permeability and electrical conductivity. 

Mike: X-ray inspection systems detect a broad range of foreign objects, such as metal, glass, mineral stone, calcified bone, high-density plastics, and rubber compounds. Additionally, they perform multiple in-line quality checks simultaneously.

Paul: This is the big question for many food manufacturers! There are multiple factors to consider. For example, if metal is the only likely foreign material contaminant on your line, metal detection is a great choice. If you are concerned about detecting a broader range of foreign objects such as glass, stone, bone or dense plastic and rubber, x-ray inspection is an invaluable tool.

Food manufacturers also need to consider the properties of their products, as well as how they are packaged. For example, products that need to be inspected vertically prior to bagging, such as potato chips, would require a throat metal detector which can be used in Vertical Form Fill and Seal (VFFS) applications. If additional quality checks are required, such as looking for missing or broken components or checking for any product trapped in the packaging seal, x-ray inspection is an ideal option.

A combination of the two technologies is suitable when both are required by retailer contracts, or when multiple foreign object contamination risks are identified at different Critical Control Points. For example, metal contamination is commonly identified as a risk at in-process steps due to the amount of metal used in production machinery. However, additional packaging and integrity checks may be needed at the end of production.