Detecting Tramp Metal in Food Products

Detecting tramp metal in food products is a little known, though highly important, part of quality control in the food industry.

In other industries where stray bits of tramp metal may accidentally contaminate a product it is standard procedure to use powerful overhead magnets to isolate and remove the particles. But this procedure alone is not adequate for products that eventually wind up on our grocery shelves. While magnets play their part in keeping food pure and unadulterated, additional steps and machinery are included to safeguard American foodstuffs.

Standard procedure in the food industry to protect against tramp metal has included x-ray and metal detectors for the past forty years. This additional layer of protection has meant that the American public has been spared any serious outbreaks of metal poisoning or gastritis due to the inadvertent ingestion of metal particles. This technology needs to be constantly monitored and updated to keep food products completely safe and uncontaminated.

For example, NWF Foods of Horn Lake, Mississippi, use a number of x-ray machines in their facilities in order to inspect food items that come off the assembly line wrapped in foil. Any article found contaminated with tramp metal or any other superfluous item is immediately removed from the system and destroyed. The company also uses a metal detector for food processing on their diverse line of products, which includes English muffins and ice cream cake rolls. These devices are meant to insure that each individual protect it tramp metal free before it is shipped out to the warehouse for distribution.

But NWF project engineers began noticing that the vibration caused by the constant movement of products on the conveyor belts could possibly be interfering with the detection of tramp metal particles. This raised concerns among them that some stray particles might not be detected as quickly or as efficiently as they should be. So they called in consultants from Fortress Technology, one of the foremost metal detector technology companies in the United States.

Working closely together, the two groups were able to both upgrade the drop-through metal detection process and to eliminate some of the more egregious shimmying on the conveyor belt that had been noticed. This put paid to any further worries about contamination prior to product being shipped out to the the various distribution centers, not only in the United States, but also overseas.

What causes the initial deposit of tramp metals in food products prior to packaging and isolation is a problem that both food engineers and structural scientists have been working on for years. It was initially thought that heavy foil bags that were often used for storing large quantities of dry products, such as legumes, cereals, and spices, were prone to micro-flaking, leaving behind a small amount of tramp metal while in the process of being transported. But today’s foil pouches, of whatever size, are coated with thin layers of polystyrene to protect against the possibility of contamination. Other sources of tramp metal might be lightweight metal fibers that are shed from binding wire and other metal binding materials that come in for heavy friction. This problem has been investigated and solved by the use of powerful ventilation systems in modern food processing plants, so that not only is the product protected against floating metal fibers, but the workers are also spared the unpleasant possibility of inhaling any such thing.

Thanks to the vigilance of American food processing engineers and the expertise of metal detecting companies, the food Americans serve at home and are served at restaurants is the safest, most painstakingly processed in the world!

Melissa Thompson writes about a wide range of topics, revealing interesting things we didn’t know before. She is a freelance USA Today producer, and a Technorati contributor.