Powers of detection

Safety first has always been a sensible watchword – the other side of the coin imprinted with the equally cautionary maxim that prevention is better than cure. And no more so than when it comes to maintaining confidence in what we ingest.

As anyone who’s ever abruptly stopped visiting a hitherto favourite restaurant will testify, it only takes one bad dining experience to nullify a score or more of good ones. Consumer loyalty may be fickle, but with so much available choice how can it be anything other?

The fact is that when buying food we do sometimes end up with more than we bargained for: a fly in the ointment; a metal shaving in the cheese; a piece of broken bone in a tin of consommé. The return of a faulty product to the retail store at which it was purchased will usually result in an instant refund to the consumer, and an automatic fine of at least £500 imposed upon the supplier; deemed guilty until proven innocent, pending further investigation at their own cost.

So far, so damage limitation. At the other extreme of the complaint scale, however, is a product recall: bad news wherever you are in the supply chain. So not surprising that the ones we get to hear of probably equate to only the tip of an iceberg whose existence the food industry would prefer to downplay if not actually deny.

Driving standards

“Manufacturers are always very shy of telling you how many products were affected, and how many they actually get back,” says independent sector watchdog Recall UK director Barry Mulcahy. “In food recalls, I believe the typical recovery rate is well under 25%, which means that in the batch that was deemed to present a risk to the public, more than 75% was consumed prior to recall taking place.

“How much does a recall cost? No manufacturer is going to quantify it if they can get away with it. However, sometimes there’s no option. Having initially pegged the cost of the recent recall of its Robinsons Fruit Shoot drink at between £1 million to £5 million, Britvic is now estimating it could be as much as £25 million, and is issuing a profits warning as a result.”

While Britvic’s woes are due to a potentially faulty closure design rather than an alien invasion, they undoubtedly illustrate the consequence of the potential damage to any brand or product in the event of a manufacturer getting it wrong. Mistakes happen, of course. But all the more reason that those that can be reduced or avoided altogether should be, at all costs, through efficient management practice and the adoption of appropriate QC technology, delivered in the main via either metal detection or X-ray systems.

Unappealing though the prospect might be of investing in non-directly productive technology, not least within the context of falling sales and squeezed margins, the retail end of the supply chain has gone beyond the exacting of token fines to ensure that packer/fillers take responsibility and bite the bullet. Standards established by bodies such as the BRC; the US-based SQS (Safe Quality Food); FFSC 22000 (equivalent of the ISA 22000); and the IFS (International Food Standard) are increasingly being co-ordinated beneath the GFSI banner (Global Food Safety Initiative) towards achieving greater harmonisation of regulation.

Most of these standards tend to be based on the HACCP principles (Hazards Analysis Critical Control Points), serving as the start point for any food manufacturer in selecting QC equipment.

“Most suppliers of own-label products are required to achieve certification against the British Retail Consortium’s global standard, which has been updated to place even greater emphasis on what methods are in place to guard against and detect any foreign body contamination,” notes BRC technical director for global standards David Brackston.

“It’s likely that this increased focus on food safety has encouraged further investment in machinery and technology to eliminate the problem whenever possible. It’s essential that retailers can be confident in the quality and safety of the food they sell,” he stresses.

Retailers are positioned to use their influence to push up standards amongst their suppliers to the benefit of consumers, adds Brackston, and for more than altruistic good intention. With own-label products from the UK’s top six multiples accounting for over 50% of total recalls instituted last year they have significant brand equity and integrity of their own to protect.

Although it’s still positioned at the lower reaches of the overall hierarchy, X-ray increasingly represents a challenge to the longer-established metal detection as the the de facto QC technology for future food and pharmaceutical packing and filling lines, not least due to the growing use of metallic containers for ready meals, notes S+S Inspection MD Richard Lines.

“When metallic or foil packaging is used or there is a need to confirm that the contents are complete and undamaged, X-ray inspection combined with image recognition software may be the only effective method,” he says.

“An added benefit is its ability to detect flavour clumping and under or over-filled containers simultaneously with foreign body detection.”

Mettler Toledo communications manager Neil Giles confirms that while growth in metal detection has been reasonably moderate or even static in recent times, the company’s X-ray business has been growing significantly. Even so, it does still have to contend with some grey areas.

“As with any technology there are some restrictions as to what it can do,” Giles concedes. “While it’s able to detect items like stone, glass, some plastics and, indeed metal, where it struggles is with lower density items such as insects which, to be realistic, no system apart from the human eye would be likely to pick up.”

That capability to distinguish between slight differences in densities is constantly improving, however, says Ishida Europe’s marketing manager Torsten Giese. “It’s a validity issue to determine whether what you’re seeing is a contaminant or not. Cartilage, for example, will be almost indistinguishable from bone, so the software has to be very carefully configured to differentiate between items that should or shouldn’t be present.

“Broken glass in a glass bottle, for example, could be a problem so you need to mask the packaging in order to detect the item that shouldn’t be there. It’s also possible to look from different perspectives; looking at a bottle or a can from the side on makes it easier to detect something that shouldn’t be there.”

For all its upsides, however, X-ray in common with any QC system will only be as good as the people operating it. “We’ve worked intensively with retailers to ensure that the machinery at end of line is easy to use and as foolproof as possible, including the integration of a number of fail-safe features,” notes Loma Systems UK sales manager Tony Bryant. “But it’s important that these systems are still managed at a technical level.”

Down to the metal

Unlike most other manufacturers of QC solutions, Lock Inspection has deliberately opted to focus exclusively upon metal detection technology which, while ruling out a fairly extensive range of packaging applications (such as foil and in certain cases, film) and by definition non-metallic contaminants, still sees it supplying around 2,000 complete systems per annum.

“It’s our view that product contamination is primarily a management rather than a machinery discipline,” explains marketing & sales manager Simon Taylor. “If the line is being operated to appropriate standards, then ingredients should be free of contamination before they enter the process prior to packing/filling. That limits the main risk as being from the machinery itself (such as stray bits of metal), thereby making X-ray an unnecessary expense.”

Indeed, notes Taylor, unnecessary reliance upon X-ray could indirectly be construed as a sign of counter-efficiency.

“On a well-managed site there will be such a major focus upon trying to minimise the possibility of a foreign body ingressing into the process in the first place, that the metal detector is more of an insurance policy, if you like, that’s there just in case of any unanticipated problems.”

Aside from fitness or rather necessity of purpose, there’s also cost of investment. Whereas Lock’s point of entry metal detector head can be installed for around £5,000, a basic X-ray system will be four times as much.

With some packer/fillers operating 20 or more lines, there’s a compelling argument in favour of the adoption of lean management principles supported by specifically focused technology.

Spotting the leaks

One thing that metal detection, nor even X-ray technology, can accomplish with any certainty is the detection of faulty sealing: the root cause of leakers that can occur in flexible film packaging applications – an issue now being addressed by Multivac’s newly introduced seal seam scanner.

The Multivac Vision System (MVS) scans the seal seams while they are still in the thermoforming packaging machine, explains technical manager Dr Hendrik Frank. “The film, and therefore also the seal seam, is fed and held very precisely in the packaging machine.

“The line scan camera can even focus reliably on seal seams in flexible film or other pliable materials. In contrast to transport conveyor systems, on which the products can jump around, the inspection level remains precisely fixed. This lack of dependence on the film material, combined with the increased security during image taking, show how sensible it is to integrate the seal seam inspection into the packaging procedure itself.”

Inspection is fully automatic, captures 100% of all packs and is wear-free as it’s performed without any contact. The scanner will detect foreign bodies as small as 0.5mm² in the seal seam as well as detecting incomplete seal seams or faults such as creases or bubbles.

Qipack in Belgium is also focusing on in-line checking of the seal seam of flexible packaging and the seal of thermoformed trays via an infra-red camera inspection technology initially developed at Leuven University (Belgium), which it is now ready to commercialise, says co-owner Alexander van Puijenbroek. “HD images captured immediately after sealing are analysed by proprietary software that detects any abnormal seal that comes along, with any leakers automatically removed from the line regardless of production speed. The system also monitors how efficiently the production equipment is functioning and whether maintenance has to be scheduled.”

Incorporating additional facilities such as track & trace capability, the Qipack system is likely to cost around €50,000. “The aim is to detect leaks while in-line, withdraw the products and re-package accordingly,” says van Puijenbroek. ‘‘I know of companies operating in the market that are habitually experiencing a leak rate of around 5%. Our aim is to reverse that by enabling them to achieve a 99% success rate.”