This article was published in the November 2024 issue of Pet Food Processing. Read it and other articles from this issue in our November digital edition. 

Detection systems like metal detectors and X-ray machines streamline production by automating the inspection process, reducing manual checks and minimizing the risk of contamination in pet food. 

Inline detection systems play a crucial role in ensuring that pet food is free from harmful contaminants, such as metal, glass or bone fragments. By eliminating these risks, manufacturers can confidently market their products as safe, which builds consumer trust. 

“The consistent quality and safety provided by detection systems reassures pet owners that the food they are buying for their pets meets the highest safety standards,” said Eva Bar of Anritsu Product Inspection & Detection.

“The consistent quality and safety provided by detection systems reassures pet owners that the food they are buying for their pets meets the highest safety standards, which is especially important in an industry where consumers are highly concerned about the wellbeing of their animals,” said Eva Bar, senior marketing manager for Elk Grove Village, Ill.-based Anritsu Product Inspection & Detection. “Inline detection systems help manufacturers identify and remove contaminants in real time, reducing the risk of unsafe products.”

Metal contamination can occur from machinery wear and tear, while glass and bone fragments may come from raw materials. These contaminants pose significant health risks to pets, and their presence can lead to recalls, brand reputation damage and regulatory penalties.

Inline detection systems on processing and packaging lines allow continuous monitoring without slowing down production. 

Barry Voorhees, product manager of metal detection for Newton, Kan.-based Bunting Magnetics, noted detection systems play a critical role in maintaining product purity and optimizing the efficiency of the production process. 

“By integrating these systems at multiple stages, contamination in raw materials can be detected and removed early, safeguarding both product quality and the integrity of processing equipment,” he said. “This proactive approach reduces the risk of equipment damage caused by foreign materials, which can significantly reduce downtime and extend the lifespan of machinery.”

Additionally, strategically positioning detection systems before and after critical processes further enhances production efficiency. For instance, placing a metal detector before grinding or blending ensures that contaminants are removed before they can damage grinders or compromise the blend. Likewise, installing detection systems after blending and before extrusion adds an extra layer of protection.

“A final inspection before packaging ensures that any remaining contaminants are detected, preventing compromised products from reaching consumers,” Voorhees explained. “These multiple layers of detection provide better monitoring and evaluation of both product quality and the condition of the processing equipment. By minimizing contamination risks at every stage, the production line operates more smoothly, with fewer interruptions and a higher standard of product quality.”

Eric Garr, regional sales manager, Fortress Technology, Toronto, noted metal detection isn’t generally put in place to improve efficiency but, applying the technology correctly will result in the best performance and lowest rate of false rejects. 

“In general, it is always more efficient to catch a contaminant before it gets to the customers, versus a costly recall,” he said. “Typically, utilizing an automatic reject device is advised to avoid disruptions to the production line.”

Getting the job done

Anritsu designs and manufactures advanced inline detection systems, including metal detectors, X-ray inspection systems and checkweighers. These systems are used to identify foreign contaminants, ensure weight accuracy, and maintain product quality throughout production lines. 

Bunting’s gravity fall metal detectors are designed to reject contaminated material, removing it from the product stream. 

| Source: Bunting Magnetics

“Our equipment stands out because of its exceptional sensitivity and reliability, which helps manufacturers maintain compliance and reduce product recalls,” Bar said. “For instance, our Dual Energy X-ray detection system enhances precision in detecting contaminants of varying densities, providing superior accuracy compared to conventional systems.”

Operational efficiency is also enhanced through automation. 

For example, Anritsu’s checkweighers and X-ray systems can integrate with data analysis tools to provide insights into production efficiency, such as identifying bottlenecks or trends in contamination, leading to process improvements and reduced waste. In fact, one of Anritsu’s clients in the pet food industry reduced its downtime by 10% and significantly lowered product rejections due to false positives by using the real-time detection systems.

Bunting’s metal detection systems are designed for a variety of applications, including pneumatic conveying, liquid conveying, gravity-fed and conveyed packaged products. 

“What sets our systems apart is their ability to detect smaller contaminants at designated critical control points, ensuring high-quality standards throughout the process,” Voorhees said. “For process applications, our equipment inspects material flow early, allowing for the detection and rejection of contaminated materials before they reach packaging. This proactive approach helps reduce costly waste and ensures product integrity.”

Bunting’s systems are also flexible to suit different configurations. For example, when space is limited — such as at the infeed of packaging machines — the sensing heads can signal the packaging machine for effective removal of the contaminated package, even without a dedicated rejection device.

“For final product inspection, we offer fully integrated conveyor systems that combine metal detection with other key quality control features,” Voorhees said. “Our combination metal detector and checkweigher solutions not only inspect for metal contaminants but also verify product weight — all within a compact footprint. This multi-functional design streamlines operations, enhances efficiency, and ensures compliance with industry standards.”

Fortress looks at each application to ensure it builds the best solution for the problem — this applies to all types of configurations whether pipeline inspection of wet products, gravity inspection of dry products, as well as inline conveyor systems. In recent years, Fortress released its Halo automatic testing system, which integrates seamlessly with Contact 4.0 data logging system. 

“Utilizing these products can help to greatly increase efficiency,” Garr said. “Halo itself helps to reduce the need for operators when it comes to performance verification. It can perform the verification better, and without the requiring staff and with little to no impact on production. Furthermore, it automates the record keeping required for inspection systems.”

When combined with Contact 4.0, it can also automate the reporting side of things. Features like the high-level dashboard of grouped systems can tell processors how all the systems are operating at a glance, which helps to address issues faster. It can also be set up to send email alerts and reports to those who need it. 

Manufacturers can customize the Stealth metal detector to suit any application with custom conveyor systems and reject options.

| Source: Fortress Technology

Geri Foley, product line manager of X-ray for Mettler Toledo, which has its product inspection division in Lutz, Fla., noted there are several ways detection systems impact the efficiency of the production process.

“Having systems at different CCPs throughout the line can ensure bad product is removed early on before adding more value or needing rework,” she said. “Mettler-Toledo offers Automatic Test System which allows the periodic testing of metal detectors to be conducted in under a minute on the ground, saving operators time in the actual test time, and also not needing to climb a ladder to conduct the test.”

Additionally, the company offers data management software, ProdX, which can provide important feedback to help manufacturers identify over- and under-weight opportunities and make corrections.

Benefiting manufacturers

Metal detection systems provide manufacturers with significant benefits in both product safety and operational efficiency. First and foremost, they ensure product purity by detecting and removing contaminants early in the production process. This helps manufacturers maintain high safety standards, protecting both the consumer and the brand’s reputation, which is critical for long-term success.

“In terms of operational efficiency, detection systems also safeguard equipment from damage caused by foreign materials, reducing the risk of costly repairs and unplanned downtime,” Voorhees said. “By minimizing equipment wear and tear, manufacturers can extend the lifespan of their machinery and optimize production line uptime. The more efficiently the line runs, the greater the output, ultimately leading to higher productivity and profitability.”

The Dual Energy X-ray detection system from Anritsu can detect contaminants of varying densities, such as fine metals and small bones. 

| Source: Anritsu Product Inspection & Detection

Checkweighers can also be used to collect the weight data and point out deficiencies and address problems like product giveaway or underfilling. 

“Some can provide feedback to filling equipment to adjust fill levels on the fly, which can improve the filling accuracy, reducing reject for underweight and reducing giveaway,” Garr said. “This reduces the need for product rework, lowers cost and improves efficiency.”

Retrofitting detection systems into existing production lines can be challenging, especially with limited space. However, the key to streamlining operations lies in carefully reviewing the entire production process to identify the most effective locations for installation, based on critical control points.

“For manufacturers without existing detection systems, a good starting point is often the packaging stage, as this ensures final product purity before the product reaches the consumer,” Voorhees said. “From there, it’s important to evaluate upstream processes to pinpoint areas where equipment protection is crucial, such as before grinding or mixing stages where contamination can cause significant damage or wear to machinery.”

Additionally, looking at raw material streams can help identify potential contamination sources early on, providing multiple layers of protection throughout the process.

In some cases, a combination of these approaches may be necessary to achieve both product safety and equipment longevity, ensuring that detection systems contribute to a more efficient and reliable operation.

“From our perspective, metal contamination is one of the most critical threats in any food production,” Voorhees said. “This includes all types of metal — ferrous, non-ferrous and stainless steel. Metal contaminants pose a significant risk not only to the integrity of processing equipment, where they can cause costly damage and downtime, but also to the safety of the final product, potentially endangering pets.”

On the horizon

Stealth metal detectors from Fortress Technology have high sensitivity levels for detecting the smallest ferrous, non-ferrous and stainless steel contaminants in pet food. 

| Source: Fortress Technology

“One key area of improvement we expect to see in the future is the increasing sensitivity of metal detectors, allowing for the detection of even smaller metal contaminants,” Voorhees said. “As these systems advance, they will be able to identify and remove very small metal fragments that were previously undetectable, providing an even greater level of protection for both products and processing equipment.”

In addition, Anritsu foresees advancements in artificial intelligence (AI) and machine learning driving the next wave of innovation. 

Technology in metal detection systems is continuously evolving, and future innovations hold great promise for enhancing the safety and quality of pet food. 

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