The use of X-ray technology is on the rise — and it’s not only for doctors and dentists anymore. While they’re best known for their medical and dental applications, there are many other uses for X-rays, including the inspection of luggage and people at airports, the discovery of defects within electronics equipment and inspecting food for foreign materials.


With X-ray inspection, manufacturers and producers can have greater confidence in the safety and quality of their products. Whether those products are food, pharmaceuticals, ammunition or aircraft parts, X-ray inspection plays a key role in ensuring greater end-user safety.

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Table of Contents

What Is X-ray Inspection?


X-ray inspection uses high-energy electromagnetic radiation traveling at the speed of light to “see through” a product. Because an X-ray’s wavelengths are shorter and of a higher frequency than regular light waves, they can penetrate materials in a way that ordinary light waves cannot. 

When X-rays target a certain material, they penetrate that material, and the light waves emerge on the other side. The presence of foreign objects means the density of the product will change, making it difficult for the light to pass through. When products are missing from a case of packaged goods, or when there are cracks or abnormalities in a product, that will be indicated by the X-ray.

This approach makes abnormalities or the presence of foreign objects easy for X-ray inspection systems to detect.

Types of X-ray Inspection Machines


X-ray inspection machines have three essential components:

  • X-ray generator, which is used to send X-ray beams through the product
  • Detector, which is the surface the X-ray beams strike when they exit the product
  • Control system, which compiles a grayscale image of the product being examined

While they work on the same principle, X-ray inspection machines come in different formats and have various abilities and applications. When considering an X-ray inspection machine, it’s important to review the differences in formats and understand what kind of environment it works best in, what types of products or packaging it’s most compatible with and what the desired sensitivity for the machine will be.

X-ray inspection machines will fall into one of the following categories:


Vertical beam systems. Most commonly used on production lines and can accommodate items that are smaller in height than in width and length. The X-ray generator is typically mounted in the top of the cabinet and shoots the beam downward through the product and the belt to reach the detector.


Horizontal beam systems. Good for products in tall, rigid packaging. The generator is installed in the side of the machine and scans through the side of the container.  


Combination system. A combination of vertical and horizontal beams can be used to improve coverage and detection.

X-ray Inspection vs. Other Forms of Detection


Keeping food safe has been a top priority for food producers, and with the creation of the Food Safety Modernization Act, they were tasked with developing better safety measures.

 Technology has boosted the evolution of inspection and detection processes. It has made food X-ray inspection the most effective way to detect and resolve the presence of foreign materials. Of course, it’s not the only option. Here’s a look at the primary types of contaminant detectors and how they work.


Magnetic separators. As the simplest way to keep unwanted materials out of inventory, magnetic separators use a constant electric current to create a magnetic field. They are used to gather ferrous objects, which are items that contain iron, and some stainless steel, and are less expensive than other types of detection. However, the capabilities are limited and these systems aren’t able to find nonferrous metallic items like aluminum or brass. They  are also ineffective when it comes to processed or packaged products including baked goods, bottled liquids and canned goods.


Metal detectors. The most common metal detector is the balanced coil system that uses high-frequency radio waves to find metals in dry and finished products.They are normally able to locate most types of metal, although they don’t work well with wet or salty material or with most types of metallic packaging. Another type of metals detection system, called the ferrous-in-foil system, can find iron fragments in foil containers.


X-ray inspection machines. Unlike the previous two types of detection, X-ray inspection can find a wide array of materials. This includes metal, glass, plastic, bone, stones, rubber, wood and more. What’s more, systems such as FlexXray’s custom medical-grade equipment can locate contaminants as small as 0.8 mm, and often smaller!

As food production lines get faster and consumer expectations surrounding food safety continue to rise, X-ray inspection has become increasingly popular due to its exceptional detection capabilities, reliability and its ability to ensure product safety.  


Safety of X-ray Inspection


One of the biggest concerns raised about X-ray inspection is radiation and, in particular, how it will affect the safety of the product.

X-ray inspection systems use high-voltage tubes, not radioactive materials, to conduct X-rays. Today’s equipment is more efficient and can operate at as much as 70% lower wattage than the systems that were used a decade ago.   

In terms of food production, the amount of radiation individuals receive from consuming X-rayed food is very small. A banana will have about .01 millirem, or mrem, after X-ray inspection; by comparison, a dental X-ray has 1.5 mrem.

Due to the low amount of radiation that occurs, the FDA has determined that eating food, drinking beverages or using medicine or cosmetics that have been X-rayed will not have any adverse effects on the end user.  

How X-ray Inspection Systems Detect Contaminants in Food


X-ray inspection is an effective way to identify physical contaminants in food. One of the most important differences in X-ray technology and other screening processes used in the food industry is that X-ray equipment can find contaminants that other forms of detection cannot.

This includes metal, bone, plastic, glass, wood, stainless steel, rubber and more. Because of the sophisticated nature of X-ray machines, they can detect the presence of materials as small as 0.8mm, or even smaller in some cases. They are able to handle a number of different package and product formats, and can distinguish between actual contaminants and anomalies like metal retaining clips and packaging.

X-ray inspection machines safely pass low-energy rays of light into the product as it passes through a detector. Each item being X-rayed is able to absorb a certain amount of that light energy. When the X-rays encounter a dense object, it’s harder for the rays to pass through it. The foreign object is detected because it absorbs more rays than the non-contaminated areas around it, and therefore appears as a darkened or shaded area.

As incidents of contamination grow, such as the growing problem of plastic contamination in food, the capabilities of X-ray systems become increasingly more valuable. X-ray inspection systems can detect the presence of physical hazards and ensure that the contaminated product never goes into distribution.  


Types of X-ray Machines in Food Inspection


Many companies have moved away from other forms of detection and added inline X-ray inspection to their production process. However, it’s important to note that even though both types of processes utilize X-ray inspection, the manufacturing environment and the environment dedicated entirely to X-ray inspection are not the same. Knowing the difference between the two types of X-ray processes can help provide insight into how each can best be used.

Inline inspection machines typically use flat panel technology that was created to fit within the production environment. It is more compact, and similar to what is used by the TSA for baggage screening. Such machines run at a faster speed and, while they will flag contaminants and issues, the speed of the production line does not allow for them to stop the machine for closer inspection.


Third-party inspection services have different environments, and the equipment is larger. For example, FlexXray’s equipment uses custom, medical-grade technology that runs at a slower speed with a lower power source to allow line technicians to observe each item as it is X-rayed.

When a change in density appears, the line can be stopped. The equipment is capable of zooming in on the area in question to provide a closer look, and determining whether or not it’s a foreign material that needs to be removed from the line based on the customer’s contamination parameters.

When used together, inline and third-party X-ray machines can offer assurance that products are safe from contaminants. Inline machines can flag a problem, while FlexXray’s inspection system can pinpoint the source and location of the issue and prevent it from reaching the end user.

Calculating Total Cost of Ownership


When it comes to purchasing X-ray equipment, manufacturers have several factors to take into consideration. While the purchase price, accuracy and versatility all contribute to the decision, it’s also important for manufacturers to calculate the total cost of ownership (TCO) to avoid unwelcome surprises.

Looking at the TCO for machines that can last a decade or more can help make the decision-making process more clear cut. By considering both the savings that the machine provides and the expenses that it will incur either directly or indirectly, decision-makers can view the cost of the investment over its entire lifecycle.

Calculating indirect costs is more difficult than adding up direct costs, but it’s important for managers to consider possible impacts on productivity and profitability.

While some costs are one-time expenditures, others will be ongoing for the life of the equipment and should be projected out over time to accurately gauge the TCO.


When to Outsource X-ray Inspection


When contamination occurs or is suspected, using an outside vendor can help identify and resolve the problem quickly, without affecting the company’s productivity. Even with an inline X-ray inspection machine in use, a third-party X-ray inspection can be the most efficient and cost-effective way to manage such a situation.

FlexXray’s X-ray inspection services specialize in detecting contaminants or flaws in the product run. It’s not just part of the process; X-ray inspection is the process.   


By outsourcing inspection to FlexXray, businesses enjoy several benefits, including:

  • Ability to continue operations at the facility while the product in question is being inspected off-site

  • Less product waste and less wasted money because only the contaminated product, not the entire product run, will need to be disposed

  • Company’s production schedule can stay on track, as FlexXray can inspect an entire truckload and have the product back on the road for distribution in as little as four hours

  • Distribution continues as planned with the complete confidence that the product is safe for consumers

  • Greater traceability when contaminants are found

  • Continued customer trust and brand protection

Make Sure Your Product Is Safe


When you’re ready to take product safety to the next level, FlexXray’s X-ray inspection services can provide what you’re looking for. Whether you rent one of our custom medical-grade X-ray machines or have your product shipped to one of our facilities, you’ll receive immediate attention and be assured that your product is safe for consumers.

Contact us today to find out more or send a sample for testing.