X-ray machines vs metal detectors

Often seen as competing technologies, Fortress Technology has highlighted that food metal detectors and food X-ray machines have a single ‘quality control’ goal — detecting contaminants. Both have a place on food production lines and can strengthen food safety when used together.

Among growing demand for both technologies, Fortress is adamant that each technology has its respective strengths and limitations.

Metal is the most common high-risk contamination culprit, often caused by fragments that break off during mechanical cutting, blending and processing operations. Each sector has its own set of more prevalent risks — for example, bones and teeth in meat and poultry or stones and seeds in fruit and vegetable applications. There are also human PPE risks from hairnets and masks.

According to European Managing Director Phil Brown, X-ray machines can identify denser contaminants like glass, ceramic and bone, but there are certain metals they cannot detect in food products, which are visible to metal detectors. These include lightweight foil strips found in PPE and very thin box blades.

Metal detectors tend to be designed around each application and factory line configuration, such as incorporating an incline conveyor in this plant.

The performance and efficiency of production equipment is a key consideration to food processers. Aside from the upfront price, Fortress reports that the most overlooked cost is the maintenance, calibration and testing of X-ray equipment. Usually, this is minimal with metal detectors.

Metal detectors do not contain any heat sources and can quickly be repaired by maintenance teams, whereas X-ray machines usually cannot be repaired in-house due to safety concerns.

X-ray machines are typically located towards the end of the processing line, often after packaging, whereas metal detectors can be used for in-process inspections as well as end-of-line checks.

The lifespan of X-ray machines can be shortened by water, dust, heat and cold temperatures, and as such, the machines are rarely deployed upstream in bulk, farming, gravity, ingredient or raw processing areas in a food production factory. Metal detectors can withstand more challenging environments, including flour and rice mills, as well as snack gravity applications where product is moving through an aperture at very high speed.

X-ray machine with acrylic windows

Modern food X-ray machines are designed to shield operators from harmful exposure to X-rays. Fortress X-ray units, for example, contain high-density acrylic windows with interlocked doors. Training staff regularly is still critical, however, to ensuring all operatives are following the correct safety precautions. There are strict regulated radiation leakage and dosage limitations when using a food inspection X-ray.

“Every technology advancement helps to build a safer food environment for all, protecting consumers and suppliers. Previously, it might have been harder to justify the cost of having both inspection technologies on a single line. However, given that even the best systems are not infallible, there are certainly occasions where have both metal detection and X-ray could be warranted,” Brown said.

Fortress Technology offers food processors a service that tests products on both a metal detector and X-ray system, presenting them with detailed reports and analysis to help with decision-making.