Meddling with Metals: The Purpose of Metal Testing in the Food Industry

metal detectors

When it comes to making food products in the twenty-first century, one thing to know is that every aspect of the manufacturing process is currently or is very soon about to be quantifiable and analyzable. Food safety is one aspect that must be accounted for at every step of the way.

This means not only knowing what ingredients are in a good product, but what contaminants may be in them as well. Food grade metal detectors have come a long way in the past fifty years, and are now one of the most indispensable tools in a food manufacturer’s arsenal. Here is some basic information on their purpose in the food manufacturing industry.

The importance of metal detectors

Metallic objects are found everywhere in this modern day and age. From cooking utensils to rocket ships and everything in between, there is simply no avoiding contact with metal throughout one’s day. In the world of manufacturing, metallic objects are particularly prevalent.

Forklifts, welding tools, conveyor belt nuts, and bolts, mixing blades, bowls, the brass button on the CEO’s jacket – any of these items can come into contact with food products throughout the manufacturing process, often more than once, creating a number of risk points for contamination. As such, industrial metal detectors play an important role in ensuring that food products are free of metal contaminants, keeping both consumers and employees safe from harm.

Without a safety plan in place and food grade metal detectors properly inspected and implemented, the number of people accidentally chowing down on a rusty bolt would be unconscionably high. Employees would also be at risk of injury if for instance machinery were to break down whilst processing large metal contaminants, sending smaller pieces of metal flying in all directions. While this may seem exaggerated, anybody who has been in the manufacturing industry long enough has heard of or knows of somebody who has been seriously injured on duty. It’s simply better to be safe than sorry.

Related: How to Ensure Quality and Safety with In-Home Product Testing for Food and Beverage Products

Metal detectors and the manufacturing process

It’s important to think about where and how to implement metal detectors in the food manufacturing process in order to optimize their utility. At the very least, a metal detector should be implemented at the end of the production line in order to ensure that packaged products ready to be shipped off are indeed free of metal contaminants before they leave the factory floor.

The beginning of the production process is also another important place to install metal detectors, as it is better to detect contaminants in raw materials before sending them down the line to be processed by expensive equipment. Large pieces of metal found in raw materials that accidentally get processed are at risk of destroying machinery, creating another source of potential contamination. As such, metal detectors can are often placed before particularly important pieces of processing equipment. Broken equipment can cost quite a lot of money to repair, and can put employees in a dangerous situation. It’s also important to note that if metal contaminants get processed into very small particles, even industrial metal detectors will have a hard time picking up on their presence, putting consumers at risk of ingesting them.

How do they work?

Metal contaminants are either ferrous (magnetic and easily detected), non-ferrous (non-magnetic, relatively easy to detect) or stainless-steel (generally non-magnetic and difficult to detect). The two most common types of metal detectors for food industry use are general balanced-coil metal detectors and ferrous-in-foil metal detectors. Most modern detectors are able to provide plenty of accurate data that can be used at a later date for analysis purposes or to assist in product recalls.

Balanced-coil metal detectors

In the case of balanced-coil metal detectors, an electromagnetic field is created by a transmitter coil. The presence of a metallic contaminant can disrupt this field, and two interconnected receiver coils can pick up on this interference, then alerting the system operator that a product is contaminated. Most modern systems have automatic rejection mechanisms, making it easy for operators to check rejected food products again to confirm if there is indeed some form of contamination.

Ferrous-in-foil metal detectors

Many food products come wrapped in foil packaging these days. This can include anything from a tightly-wrapped chocolate bar to a large frozen turkey in a tray. No matter what the product, manufacturers need to be able to get past the foil wrapping to check for unwanted metal contaminants. Ferrous-in-foil metal detectors are the perfect solution for many products, however high levels of salt or water can make it difficult for metal detectors to do their best job. As the name suggests, these detectors will generally only work on ferrous metal contaminants, as non-ferrous metals and stainless steel are not magnetic.

The magnetic property of a contaminant is important, as these detectors work by producing a magnetic field through which a food product must pass in order for contaminants to be magnetized. In such a scenario, the magnetic field is disturbed by the presence of any magnetized metallic ferrous contaminant. An operator will then be alerted about the contamination. Like their balanced-coil counterparts, ferrous-in-foil food grade metal detectors typically have a rejection system in order to separate the contaminated food from the rest of the products. Operators are then able to carry out further tests on the contaminated item to confirm whether or not it is indeed contaminated.

Conclusion

Since the 1980s, industrial metal detectors have taken on a bigger role in the food manufacturing process as savvy consumers continue to demand improved safety regulations in this industry. Indeed, governments around the world have begun to impose prevention-focused regulations, aimed at reducing the number of food-related illnesses and recalls by ensuring that manufacturers take safety standards seriously. By investing in the appropriate food grade metal detectors, companies can confidently bring their manufacturing processes into the twenty-first century, ensure that their reputation is safeguarded, and protect their customers from ingesting unwanted metal contaminants for years to come.