Modern metal detectors are divided into two types: balanced coil systems, which are general metal detectors that use coils and electronic fields, and foil iron systems, which use strong magnetic fields to detect harmful iron-containing metallic pollutants (magnetic, iron-containing) in products.
These systems come in various models, designed for different types of production and manufacturing systems, including:
The most common industrial metal detector model is the conveyor system metal detector, which can be easily integrated into any food production line due to its variety of sizes, conveyor configurations, and sensors. Pollutants can be automatically removed when detected by different contaminant removal devices.
As mentioned, the use of metal detectors in food production lines is crucial as it helps protect consumers. These devices are used in a wide range of food industries, including:
There are three main groups of metallic contaminants that food metal detectors can detect. The table below provides comprehensive information about the types of metallic contaminants and the characteristics of each:
| Ease of Detection | Electrical Conductivity | Magnetic Permeability | Metal Type |
| Easy | Good | Magnetic | Iron |
| Relatively Easy | Good or Excellent | Non-magnetic | Non-ferrous (Copper, Lead, Aluminum) |
| Relatively Difficult | Usually Poor | Usually non-magnetic | Stainless Steel |
According to the table above, the ability of a typical metal detector used in the food industry to detect metal contaminants depends on the conductivity and magnetic permeability of the contaminants:
If there are other types of contaminants (such as bone, plastic, glass, ceramic, or stone) that need to be identified, an X-ray inspection system for food can offer advanced detection capabilities.
Understanding the location of metal detectors in food manufacturing plants is crucial for their effective use. Metal detectors can be used throughout the food production process, but since contaminants can enter products at nearly any point along the production line, the best location for a metal detector is at the end of the production line. Installing this device in the wrong location can render it ineffective and lead to the overlooking of unwanted contamination. Inspecting raw materials, inspecting several critical control points, and performing the final inspection of finished products are essential for optimal protection of food products.
If the metal detector is used to protect machinery, it is installed directly before the relevant machine. In the case of the food industry, where consumer protection is the primary goal, multiple inspection points are important. Inspecting raw materials ensures that metal particles are separated before breaking down into smaller pieces, which makes them more difficult to detect. Inspection at critical control points (HACCP) during the production process is recommended to ensure timely detection of equipment failure (such as blade breakage).
The standard detection for the final product is that all magnetic spherical particles of 2mm and all non-magnetic spherical particles of 2.5mm, as well as stainless steel spherical particles of 3.5mm, should be detected. Only detectors that meet these standards can be suitable for purchase and installation in the packaging line.
The sensitivity of metal detectors is influenced by various factors in food products. In general, the following factors impact the sensitivity of metal detectors:
Food metal detectors in the food processing industry use a range of frequencies to detect metal contaminants in food. The optimal frequency depends on the type of metal, the position and orientation of the metal, and its shape. For example, stainless steel has little or no magnetic properties, so it requires high frequencies for detection. Multi-frequency technology is one method that allows operators to select up to five frequencies ranging from 50 kHz to 1000 kHz and quickly pass through them. This significantly increases the likelihood of detection and practically prevents contaminants from escaping.
Many food manufacturers recognize the need for food industry metal detectors at all stages of the production process. As a result, the market is expanding rapidly, leading to the production of more and more metal detectors designed specifically for various needs and purposes. With such advanced technology, the features of metal detectors are increasing, making it challenging to choose the right one. In general, metal detectors should have the following characteristics:
Before selecting and purchasing a food metal detector, it’s important to know where it will be positioned in your system and how to use it effectively. Metal detectors come in a wide range of sizes, designs, and functionalities, and you can order some to match your specific needs. When purchasing a metal detector, consider the following factors:
Given the numerous benefits that metal detectors provide for both food manufacturers and consumers, these devices ensure the following:
Metal detectors are a key part of food contamination control programs. When correctly chosen, installed, used, and maintained, they contribute to improved product quality and reduced waste. These diagnostic devices can identify unwanted metal contaminants in food products, ensuring the safety of consumers.
At Packen, with years of experience in manufacturing and installing high-quality metal detectors, we provide the tools and knowledge to help you purchase the most suitable metal detector for your system. Regardless of the food industry you operate in, our devices are adapted to your work environment, providing reliable data on the level of metal contamination in your food products. Trust our brand for the best and most suitable metal detectors. For device pricing and further information, contact our experts at Packen, who will guide you through the process.