How do food producers ensure the highest quality products for consumers? Manufacturers use metal detection technology in the food industry as one of several options to detect and eliminate metal contaminants from production.
Contaminant detection is a necessary component of quality control, but occasionally, when metal detectors inspect products, a phenomenon known as “product effect” disrupts the process.
Product effect refers to a product’s ability to conduct electricity and generate its own magnetic field — two elements that can interfere with the readings of metal detectors. Manufacturers have observed product effect in items with no metal contaminants, especially products containing high levels of moisture and salt content and those packaged with metalized film.
These characteristics can trigger false readings on metal detectors while inspecting products, making it critical for manufacturers to understand what causes this effect and how to prevent it from disrupting production.
How Does Product Effect Interfere With a Metal Detector?
Inside a metal detector, three primary coils work to measure conductivity and identify potential contaminants: the center transmitter coil and the receiver coils on either side of it. Products pass through the metal detector aperture, and a high-frequency signal transmits to the center coil, creating a magnetic field.
The generation of the magnetic field then sends a small voltage to each of the two receiver coils. Next, the metal detector measures the difference in the voltage between them. If everything is balanced correctly, the voltage should read zero.
When a metal contaminant passes through the aperture, it will disturb the magnetic field of the receiver coils, alerting the detector that a contaminant is present.
Detection technology allows manufacturers to find trace metals and access improved food safety solutions. The trouble arises because metal is not the only material with detectable conductivity or the ability to create magnetic fields.
Though considerably less so when compared to metal, products with high saline content also possess conductivity. When these products can trigger a metal detector in the same way as a metal contaminant, “product effect” occurs.
What Causes Product Effect in Metal Detectors?
With what is product effect associated? Several factors and product variations affect the metal detection process. Factors such as moisture and salt content, temperature, size, shape, weight, and the packaging materials can influence whether actual contaminants are detected, and can prove challenging to control on the production line.
Manufacturers refer to products with high moisture content as “wet products.” This kind of product includes items like fish, poultry, and fresh meats, which are decent conductors and can produce a signal in the metal detector that may be indistinguishable from that of a metal contaminant.
These similar signals can affect the metal detectors’ ability to find contaminants with accuracy and consistency. Product variations make this challenge even larger still. Manufacturers have thought to combat this problem by decreasing their metal detector’s sensitivity.
The problem with this method is that a lower metal detector sensitivity can allow smaller metal contaminants to pass through undetected. Additionally, it can’t account for other factors that often disrupt this metal detection technology.
Beyond moisture content, the temperature can have a significant impact on the detector’s function. A frozen product isn’t likely to cause disruptions because of limited conductivity. However, if the product begins to thaw, condensation can influence the coils’ magnetic fields within the metal detectors.
How to Combat Product Effect: Choosing the Proper Metal Detector Sensitivity
A product signal can also change, depending on the size and shape of a product. Some products maintain the same size with little variation, making product signal detection much easier for the machine. However, products like ready meals, for example, have varying ingredients and bone content in the different meats, making it more challenging for metal detectors to determine a consistent product signal.
Packaging materials can also increase the frequency of false triggers within a detector. Metalized film is particularly problematic, as it possesses a relatively high level of conductivity that can disrupt the detection process.
Ideally, manufacturers can find a detection solution that doesn’t require compromising the detector’s sensitivity. Most modern metal detectors use a technology referred to as multi-simultaneous frequency (MSF), which operates with more than one frequency at a time.
This combination of high and low frequencies allows manufacturers to avoid compromising sensitivity levels while differentiating between product effect and an actual contaminant.
MSF also ensures that the detector can successfully detect a small, trace contaminant, even in products with significant variation.
The electronics in most modern detectors account for both product effect and variations in the products themselves. Product signal suppression technology allows for precise inspection and decreases the likelihood of false readings.
Invest in Industry-Leading Metal Detection Technology
Manufacturers must invest in effective inspection technology to ensure food safety and superior quality control. Detectors that use multi-simultaneous frequency allow operators to perform thorough inspections without sacrificing sensitivity settings or risking undetected contamination.
At TDI Packsys, we understand how critical food safety is for the manufacturer and consumer alike. After years of assisting manufacturers and building top-quality detectors, we have the experience to assess your production system and improve it accordingly. Whether you produce and package food, pharmaceuticals, or other related products, our industry-leading machines will provide increased efficiency and state-of-the-art food safety solutions.
Our experts design each of our detectors to your specifications to ensure quality, efficiency, and customer safety. From independent food companies to massive production facilities, we provide the best detection machinery on the market.
It’s essential to determine what type of detector best suits your existing system before purchase, as various designs and functions are available. However, a modern detector with MSF can significantly improve overall product quality and ensure safe packaging practices. A professional-grade detector can also prevent false readings and easily spot the difference between what is product effect and what is a contaminant.
Our experts can tailor a customized solution to your specific application. Call our TDI Packsys team at 877-834-6750 to discover how we can improve your metal detection system in the food industry today.