The modern food industry resorts to various inspection methods to ensure the quality and safety of food products. Among many used is X-ray food inspection, a non-destructive method created to detect physical contaminants, such as glass, metal, and bone fragments.
X-ray inspection is quite prevalent in the food industry because it quickly provides a detailed image of the internal structure of any packaged food. This allows manufacturers to maintain high safety standards before introducing their products to consumers.
Considering the heightened awareness of many foodborne illnesses and the complexity involved in food supply chains, it is more important than ever to ensure food safety. Any negligence can damage a brand’s reputation and lead to severe health risks. The problem is that though the X-ray inspection method is quite effective, it may not produce accurate results based on the packaging types and materials.
The Role of Packaging in the Food Industry
Packaging is vital in the food industry, but it is just as important to learn how packaging affect food x-rays. Food packaging helps shield food products from physical damage, external contaminants, and other environmental factors. It also helps extend shelf life and shares important details about nutritional value, ingredients, and usage.
The most common packaging materials include glass, paper, metal (tin-plated steel, aluminum), and plastic (HDPE, PET, PVC). Some manufacturers may also resort to flexible packaging that uses multi-layer laminates. All these types of packaging play an important role in maintaining food safety, quality, and marketability throughout the supply chain, but they also affect how the X-ray inspection works.
The Impact of Packaging Materials on X-Ray Inspection
Most food product manufacturers choose X-ray inspection over traditional methods, such as metal detectors, visual checks, and manual sorting. The X-ray systems can easily find a wide range of contaminants, including stone, glass, bone, and even some plastics. Moreover, it can also help with additional quality checks, such as counting components, measuring fill levels, and identifying missing/broken products. However, the effectiveness of this inspection method changes with a change in packaging materials and designs. For instance:
The Impact of Thickness and Density
The thickness and density of the packaging materials have a direct impact on X-ray image quality. Metal and glass are high-density materials, meaning they can absorb more X-rays and lower the effectiveness of this inspection method. Similarly, thicker packaging makes it harder to detect small contaminants using X-ray imaging.
On the other hand, plastic containers and trays are usually the best for not interfering much with X-ray inspection. Because plastic is a low-density material, it allows X-rays to pass through, which helps produce accurate results.
The Impact of Metal
When the packaging uses metal components, such as metalised films or foil lids, it significantly lowers the effectiveness of X-ray inspection. Foil lids are known for creating “blind spots” in X-ray images, while metalised films restrict rays penetrating through them. Metal cans with ribbing and ring pulls can also result in low image quality. Similarly, multiple layers of low-density aluminum foil can reduce image clarity and detection sensitivity.
The Impact of Multiple Layers
Food products using multi-layer packaging also complicate X-ray inspection, mainly because each layer comes with a different density, potentially affecting X-ray absorption patterns. The use of several layers also increases overall thickness, reducing X-ray penetration and resulting in image artifacts.
The Impact of Design and Shape
Different packaging designs and shapes can also influence X-ray inspection, as irregular shapes often result in inconsistent X-ray absorption. Designs with sharp corners and edges can potentially create “blind spots” and even distort images. Similarly, the whole inspection process becomes less effective due to features like dividers or compartments within the packaging.
Plastic is a low-density material and suitable for X-ray inspection. However, the effectiveness of X-ray inspection comes down when plastic packaging uses irregular corners and shapes. This can again lead to the creation of blind spots, making it difficult to spot some contaminants.
Sometimes, an otherwise suitable material for X-ray inspection may still pose challenges. For instance cardboard and paperboard are low-density materials and don’t interfere much with X-ray inspection, but it’s a different story with the use of recycled cardboard. In this case, there’s always a risk of false positives because recycled cardboard is likely to contain small metal fragments, such as aluminum foil bits.
Is It Possible to Mitigate Packaging Interference?
You can use various strategies to lower the impact of packaging material on X-ray sensitivity and avoid issues when working in the food industry. For instance:
- Change the system settings to match the type of packaging material you use. You can calibrate the machine to deal with different thicknesses and densities of packaging. For instance, choose higher energy settings when handling denser materials like metal or glass, and stick to lower settings when inspecting paperboard and plastic packaging. Some machines also allow you to use advanced image processing algorithms to produce accurate results when inspecting multi-layered materials.
- Set multiple X-ray inspection points to identify contaminants that may have been missed earlier. For instance, manufacturers can have an X-ray machine at the primary packaging stage and another one at the final packaging stage. This approach also proves beneficial when inspecting individual components before they are used to create the final product.
- Identifying the right packaging suitable for X-ray inspection is important, and it can be achieved through collaboration between food safety experts and packaging designers. The goal should be to develop functional packaging that doesn’t interfere much with X-ray inspection. This involves using low-density materials in designs that reduce blind spots.
Endnote
X-ray inspection continues to be one of the best ways to ensure food safety, but never overlook the impact of packaging materials on its effectiveness. With different packaging types come unique challenges. You need to acknowledge those shortcomings and work towards mitigating their impact.
You can accomplish this by optimising the inspection process and using advanced inspection solutions, including customisable X-ray systems that can be tailored to specific packaging needs. Also educate yourself about finding the right packaging type and design to be able to maintain the highest standards of food safety and quality.
Featured image via Pixabay
