Every participant across the food and packaging industry supply chain must ensure foreign contaminants are not present in the products companies deliver to their customers. Eric Confer from Eriez outlines the best practices processing plants use today to achieve the highest product purity and avoid costly tramp metal damage by using magnetic separators and metal detectors.
Understanding the relationship between magnetic separation and metal detection is key to fostering product purity and equipment protection from the receiving dock to the shipping department.
Magnetic Separation
Magnetic separators are very effective in applications that extract ferrous and certain stainless steel before the food product is passed through metal detectors. The magnetic separation industry is constantly evolving to meet customer demands. Manufacturers like Eriez work to improve their products by applying state-of-the-art material sciences, engineering, and manufacturing processes.
Source: Eriez
An independent research team proved Eriez’ rare earth tube magnets can remove metal contamination with a pull-test strength that is 13-40 per cent stronger than other commercially available models.
Eriez commissioned Pennsylvania State University (Penn State) to determine which commercial tube magnet most effectively removes dangerous ferrous metal and weakly magnetic contaminants from process flows. Thirteen tube magnets from various suppliers were stripped of brand identity and provided to the Behrend College at Penn State for testing.
The findings showed the pull force of the Xtreme RE7 Tube Circuit was substantially stronger than any of the other samples. Eriez’ magnet was also among the best performers in terms of magnetic flux density. (Click here to download the full Penn State performance report.)
This RE7 magnet circuit is now incorporated into tube, grate, and liquid line trap-style magnets. The increased power directly and positively impacts product purity and plant productivity.
These advanced magnets balance high gauss and high pull force to influence tramp metal trajectory and hold on to the particulates, even during a wash-off process.
Many confectionery companies install a series of liquid line B-Traps or dry pneumatic RF cartridge magnets at the processing door of their plant.
When the tanker truck comes to the side of the building and hooks up its hose, the B-Traps or RF cartridges on the other side of the building/wall ensure metal is not entering the plant.
Magnetic separation and metal detection equipment should be used throughout food processing, especially at the beginning stages.
Some companies are most interested in the final package, and while that may be satisfactory, the added quality achieved by ensuring the product is monitored from the start of the process increases purity and safety.
Metal Detectors
Plant operators cannot just assume that every supplier is sending a perfectly clean product. Realistically, there are many opportunities for contamination to occur before products arrive at the processing plant.
Metal can come off the walls of a rail car. A fastener, nut, or bolt may fall off a truck. A clamp can fall through the grate on the floor. It is surprising how often these things happen.
Today’s metal detection products combine a precision mechanical design with state-of-the-art electronics, multiple frequency ranges, vibration immunity, and complex algorithms to detect the smallest metals in difficult products. Industrial metal detectors are designed for harsh wash-down environments.
In a survey, field representatives and food processors determined what they sought in terms of today’s metal detection systems:
- Customers seek metal detection systems for demanding applications. They must work in extremely low and high temperatures and also be able to withstand severe high-pressure washdowns/environments;
- in a world where contamination results in recalls, processors stress the importance of monitoring, record keeping, and sophisticated electronics; and
- food processors want to detect the smallest contaminants possible while minimising the number of false rejects.
Government guidelines drive companies to create policies, procedures, and protocols to ensure food safety. New metal detection systems can find smaller metal contaminants than previous metal detectors, even in demanding applications.
Food Safety Training and Services
Customers purchasing high-performance magnetic separators and metal detectors should have access to training.
Training takes several forms, including in-plant training and webinars. There are also tutorial videos, case studies, product literature, installation and operation manuals, and start-up installation support.
The best companies work with customers to understand their goals. What is the application? What size metal needs to be removed? Does a sample need to be assessed for contamination levels?
Customers should seek to work with manufacturers that put an emphasis on proper equipment selection.
Source: Eriez
A manufacturer must ask the right questions to ensure customers get what they need. And customer education is also essential.
The true worth of metal removal and detection should not be underestimated. Conducting an annual audit is of great value to see what changes can be made to improve product purity and protect equipment.
Raising the bar
High-powered rare earth magnetic separators, metal detectors, and smart manufacturing techniques have raised the bar for product purity and equipment protection.
Each day, diligent companies avoid recalls and damaged reputations.
Companies must look closely at technology to ensure they achieve the highest product purity possible. Proper support and training enhance value beyond the price of the purchased equipment.
Look for manufacturers who have developed a highly skilled worldwide representative network that is ready to meet processing and production challenges.
Ongoing training and support help food processors reduce the chance of tramp metal contamination, improve product purity, and educate employees.
Eric Confer is the Eriez Light Industry Team Market manager. Eriez is a global business specialising in separation technologies that includes magnetic separation, flotation, metal detection, and material handling equipment.
This article first appeared in the February/March 2025 edition of Food & Drink Business magazine.
