Focus on: Detection & Inspection

Scrutiny on the meat industry means businesses need to be at the top of their game when it comes to detection and inspection. Helen Gregory looks at what’s new in the sector. 

Product recalls earlier this year show just how easy it is for factory slip-ups to happen, and the resulting damage it can cause to reputations. Thankfully, meat products weren’t involved this time – instead, Mars and Weetabix were left red-faced when forced to admit bits of plastic had slipped into their chocolate and cereal.

But there is no room for complacency as it’s not just plastic but calcified bone, bone fragments and pieces of metal from broken knives that all continue to be potential threats to meat processors. As scrutiny of the meat industry is still very strong, they need to be at the top of their game to ensure a clean production line and to keep products free from adulteration – be it accidental or deliberate. They also need to meet BRC requirements, which includes having confirmation that a package is rejected, reject bins are locked, and there’s guarding over the conveyors. Some retailers have also created their own codes of practice for Foreign Body Contamination and those companies that don’t keep up can be downgraded in their supplier status/ratings and even risk losing contracts.

Fortress MD Sarah Ketchin explains how Marks & Spencer refreshed its code of practice last August, only to update it again in October.

“When one introduces a new clause, the other major supermarkets tend to follow suit,” she says. “Manufacturers then turn to their metal inspection suppliers for advice and immediate fixes.”

What M&S’ revision raised was the potential hazard of contaminated products entering the supply chain. Ketchin explains that, in metal detectors, a large majority of fault warnings are fixed, so that notification of a blocked photocell, low air pressure or a full reject bin would still appear as a fault, even after a reboot. However, an event-based fault – for example, a reject failure when the product wasn’t seen entering the bin – could be wiped clean when powering the system up again.

German family-owned company Haas GmbH, which supplies meat and sausage pizza toppings, recently installed Marel’s Trim Inspection System to check for bone fragments in its products.

Owner Achim Hass says that although butchers visually inspect meat, it wanted to make sure it was getting rid of absolutely all foreign bodies, including tiny bone fragments, which cannot be seen by the naked eye.

The Trim Inspection System consists of an infeed system, which ensures a constant flow of material through the system, a SensorX for measuring the chemical lean (CL) point of the trim and finding bone contaminants, and a knife reject for effectively removing a contaminant. The system also incorporates Innova software to collect information about the processed meat and generate reports to show performance.

If the SensorX X-ray unit finds a contaminant, the knife cuts out a small section from the product stream. The rejected material accumulates on a buffer conveyor for manual inspection and is rescanned later. Marel says this makes it possible to maximise throughput at the highest possible bone detection rate. When the total CL is known, the processor can manually adjust the recipe to achieve a precise final CL.

“We’ve been able to find even more bones and bone fragments in the meat, increasing product safety,” says Hass. “This provides added value for us and for our customers.”

The company issued a software update so that any fault condition was re-displayed, even if an operative innocently turned off the power to clear the fault while the machine was active, and meant M&S suppliers with Fortress Stealth and Phantom metal detectors could then meet the retailer’s audit requirements.

As part of retailer codes of practice and BRC, data collection is also essential, says Matt Taylor, Multivac product specialist inspection and weighing. Suppliers need to show traceability, and technology is helping them through the use of ERP (Enterprise Resource Planning) business process management software. “Multivac machines are all controlled by IPCs combined with PLC technology, which makes integrating ERP systems with our equipment easy, so customers can download information directly to a labeller from their own network. They can also retrieve statistics data from our checkweighers and packaging machines.”

Customers increasingly demand full traceability for all goods supplied to them, agrees Torsten Giese, marketing manager of PR and exhibitions at Ishida Europe. Its X-ray systems allow every pack image that passes through to be retrieved, which can establish beyond doubt whether or not it contained a foreign body or showed a quality issue such as a missing item.

Its Ishida Data Capture System records and analyses data from every pack that goes across checkweighers. “This provides fully customisable real-time information… and can help manufacturers to monitor line performance and identify and implement cost savings and efficiencies throughout their operations,” explains Giese.

When it comes to demonstrating due diligence in the event of a product recall, processors need to record and store product inspection data from across their production line to show that they’ve done everything possible to minimise safety risks. Data management software means processes can be streamlined, more accessible and efficient as critical inspection process data is collected in one location – significantly reducing the need to interact directly with critical control points on the factory floor.
So what technology is currently out there to help processors meet retailers’ and consumers’ demands?

Taylor at Multivac says that while X-ray inspection technology is not new it’s increasing in popularity and is also becoming less expensive and more reliable. X-ray is a particularly versatile system because of its flexibility. As well as spotting contaminants and foreign bodies, it can do other quality control checks such as identifying voids and broken, undersized or missing items in packs, or deformed products, such as a beef burger which has not been formed properly. Metal detectors can identify all types of metal based on magnetic and conductive properties, while an X-ray system depends on density differentials.

Other technology that is benefiting the meat industry is the increasing use of vision systems, as well as integrating inspection systems with the packaging lines. Multivac can connect the end-of-line inspection equipment including checkweigher, metal detector, X-ray and vision systems to the primary packaging machine (thermoformer or traysealer) via a LAN (local area network) which gives full line integration, says Taylor. “This benefits food producers as they can link all the machines and download recipes from the packaging machine to all of the end of line equipment…and reduces human error by offering an additional failsafe against wrong recipes as well as other benefits such as saving time.”

Meanwhile, Mettler Toledo’s Safeline X-ray X36 series uses advanced X-ray imaging technology for inspections in single and multi-lane applications. Designed to detect and remove minuscule contaminants in a wide range of packaging materials, while simultaneously performing product integrity checks, it has a choice of detector diodes, 0.8mm or 0.4mm detector widths and generator size options.

However, according to Fortress, no system can entirely eliminate the risks. “If stone, glass, high-density plastics or bone poses the biggest risk, a metal detector will be unable to spot them,” says Fortress’s Ketchin.

It can depend on which way the metal is facing when it’s scanned, for a system to pick it up, while stainless steel is more difficult to detect than other metals such as iron and zinc. That’s why it’s important to optimise the performance of the detector to cope with the worst-case scenario. “An improvement in sphere size from 3mm to 2.5mm may not sound like much, but it can be the difference between success or failure when trying to spot an irregular fragment,” she says.

It’s also vital to check that any metal detection system is fail-safe. So, for example, if a fault with the reject system means that a contaminant is detected but not rejected, the line should stop automatically until the situation is resolved.

And because the performance of any metal detector improves as the aperture size shrinks, so users could optimise performance by using a number of smaller detectors positioned at critical control points throughout the process, rather than a single, big ‘catch-all’ detector at the end of the line.

Mettler Toledo’s marketing communications manager Neil Giles says the product effect – the electrical signal generated by some foods with a high moisture, salt content or packaged in metallised film – has meant detection sensitivities have been significantly lower than the levels achieved with inspections of dry non-conductive food products. However, its new Profile Advantage metal detector all but removes this phenomenon, resulting in up to 50% improvements in detection sensitivity levels, irrespective of packaging material. He says: “It finds more metal contaminants than traditional systems in challenging applications such as wet, warm or chilled food.” It is also capable of rigorously reducing the number of false rejects, says Giles. “Meat and poultry producers can typically see false reject rates associated with product effect reduced by up to 95% when trying to detect the smallest metal contaminants.”

Overall Equipment Effectiveness (OEE) is a key area for processors to consider – which is the ability to assess quality performance and availability of equipment, as well as the ability to undertake tasks simultaneously. For the meat industry, Mettler Toledo’s InspireX R40LF-800 X-ray System is designed to inspect formed food products for quality parameters, such as the roundness of a hamburger patty and indentations caused by defective forming. It does this while detecting contaminants and streamlining quality control while mitigating the risks of contaminated products entering the retail supply chain.

Other new inspection units also incorporate multi-tasking. Interfood Technology’s Sparc range now has integrated metal detection/checkweighing, X-ray/checkweighing, and pipeline X-ray systems. It has also just launched a new machine system to inspect and confirm that the right product and label/sleeve and date codes are being produced, while at the same time ensuring the products are checkweighed and detected for contaminants. The systems are designed to identify specific times and reasons for downtime and continuously calculate line OEE.

Interfood’s divisional manager for packing solutions Rob Allen says there is a trend towards X-ray detection, due to its added detection capability and quality control features. “Together with our verification systems, they can provide an added level of security by ensuring each individual pack is inspected and detected and checked to make sure they comply with customer specifications at all times.”

As well as spotting contaminants, including metal up to 0.3mm, glass, rubber, hard plastic and bones, Ishida Europe’s new range of X-ray systems can also perform extra quality control procedures, such as detecting product flaws and missing items, and estimating weight. Both its IX-EN and IX-GN series use genetic algorithm image processing software, so customers can tailor their X-ray machine to a particular product. Each genetic algorithm can be tuned to focus on a specific foreign body that poses an risk to a particular product.

The IX-G2 features advanced dual-energy technology that uses the rays of two different energies to produce two images, unlike traditional X-ray systems which obtain an image using X-rays of one energy. The two images are then compared to eliminate the background effect caused by the product itself.

Belgium-based Gold Meat has installed two IX-GA machines and included extended covered infeed and outfeed conveyors, as well as a bespoke reject system. Special sensors in the reject bin signal to the machine that a rejected pack has left the line; if, for any reason, this signal isn’t received, the line is stopped so that the faulty pack can be identified and removed.

So if you’re thinking that your detection and inspection equipment might need replacing, should you take the plunge or just update?

Metal detectors can get electronic platform upgrades to enhance system performance and, at the same time, increase compliance, advises Giles at Mettler Toledo. Checkweighing equipment can benefit from an upgrade to the load cell – the heart of the machine that is subject to wear over time – whereas X-ray systems can be upgraded with the latest software to ensure they continue to run effectively.

Even perfectly functional, yet older Fortress models can upgrade to the latest electronics and USB data capture to meet evolving retailer standards. “An upgrade will only set a manufacturer back several hundred rather than thousands of pounds and the cost can be offset through the maintenance budget instead of eating into capital expenditure,” says Ketchin.

This could be reassuring for processors worried about meeting ongoing specification changes and changing retailer codes of practice. “If your equipment is perfectly functional, an upgrade can be just as effective and won’t impact on your production schedule,” she adds.

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