In today’s food industry the emphasis is on producing good quality products as efficiently as possible. One threat to this is the potential presence of metal in food products. For this reason, many companies employ the latest metal detection techniques to protect the safety of consumers and the name of their brand.

A further benefit of using meta detection technology is that its more cost effective than the x-ray processes that have been used up to now and are still utilised by some companies. The ability to remove metal from a product, before it reaches the consumer, is also a major advantage when it comes to competing in crowded market.

Why is metal detection so important?

The biggest reason for using metal detectors in the food industry is the protection of the consumer. Care is always taken when food products are produced, but there is still a chance that metal could contaminate a product during production. If this happens, there is an obvious danger to the consumer who eventually eats the product. Companies do not want anyone to be injured as a result of eating their product. They also do not want to face the potential costly lawsuits and damage to brand reputation that could be the result of any injuries that are sustained.

Metal detectors provide protection against metal contamination of food products. This protection is against both ferrous and non-ferrous metals and can be included at any stage of the production process. Metal detectors can also help to protect the machinery that is used during food production. This machinery could be severely damaged by coming into contact with metals, resulting in costly repairs.

How does the metal detection work?

There are different types of metal detection system available for use in the food industry, with the main aim always being to detect the presence of potentially dangerous metal. One of the most common metal detection systems in use is the balanced three-coil system. This system consists of:

  • Three coils wound exactly parallel on a frame that is made of non-metallic material.
  • A high-frequency radio transmitter connected to the middle coil.
  • Two outer coils intended to receive transmission. These coils receive the same signal and produce a balanced amount of output voltage.

As particles pass through the metal detection system, any metals present disturb the voltage. The system then alerts the user to the presence of metal and most systems have an automatic rejection process built in. The aim of the metal detection process is to remove all metals present but there are certain factors which can affect its accuracy.

What factors can affect results?

There are several factors that can have an adverse effect on a metal detection system in the food industry.

  • Moisture in a product can interfere with the signals from the detector so needs to be dealt with before the process of detection begins.
  • If the sensitivity of the metal detection system is set too high, false positives can be created by the presence of ingredients such as salt, vitamins and fat.

To deal with this second issue, it’s important that any company makes sure that its metal detection system is calibrated in the right way. It’s possible to decrease the sensitivity of the system or to adjust the settings so that different signals provide different meanings. Companies often use more than one technique to ensure that their metal detection operates at the optimum level.

Where does metal detection happen?

The fact is that metal detection can happen at any point during the food production process, but there are reasons why some companies choose a certain point at which to detect metals.

Start of the production line

Products such as meat, which may arrive at the start of the production process having come into contact with metal from knives or tags, often require metal detection from the start. Detecting metal at this point helps to protect production machinery from damage. This early detection is usually used in conjunction with further detection down the line in order to account for any metal contamination during the production process.

End of the production line

In many cases, companies choose to use metal detection at the end of the production process, so that all metal contamination can be checked as a whole. This works best for smaller, less dense, food products where there is no chance of larger size and increased density interfering wit the accuracy of the signal.

During the production process

Often companies choose to detect for metal at vital points on the production line, in order to ensure metal does not contaminate any part of the process and to ensure that machinery is protected.

Often, metal detection is used at the start and end of production, as well as throughout. This is hardly surprising given how important it is in protecting consumer safety and the reputation of food brands across the globe.