How Cheyney Design uses X-rays to keep our food free of foreign bodies
How do supermarkets ensure they keep unwanted bones out of fish or chicken?
And how do they spot if food is contaminated by a foreign body?
The answer, it may surprise you to hear, is that products are passed through X-ray equipment on the production line.
And business is booming for the South Cambridgeshire company that supplies the technology.
Cheyney Design has announced plans to swell its workforce from 20 to 130 as it aims to drive a tenfold increase in revenue over five years, taking it to £35million.
At its headquarters at New Cambridge House in Litlington, and its manufacturing facillity in Melbourn, the company is witnessing record orders for its equipment.
“A lot of food nowadays is X-rayed on the insistence of the supermarkets,” director Richard Parmee tells the Cambridge Independent.
“So supermarkets will ask for 50,000 chocolate cakes and ask that they are X-rayed.
“Until recently, it was deemed that putting a metal detector on the line was sufficient. But things have moved on.”
Cheyney’s technology sits at the end of factory production lines and can be used to spot metal, bone, stone, glass and even certain types of plastic. It can spot holes in bread or identify poorly distributed food toppings.
In addition to the food industry, its machines are used by the pharmaceutical and cosmetics industries.
Using algorithms and machine learning, the technology can also spot anomalies in fill levels or product weights and missing or broken components.
“As it goes through the machine, much like a baggage inspector, an image is created of the product. The image is analysed by the computer.
“It finds something wrong and it activates a pusher, or drop flap to remove that product from the production line. It’s discharged into a locked bin to prevent it being reintroduced into the production flow,” explains Richard.
Such machines use the differing degree to which X-rays, which are electromagnetic waves, are absorbed to create an image.
“X-rays are driven by atomic number. Food is organic – carbon, hydrogen and oxygen. Glass is silicon, certain plastics are detectable, bone has calcium, stone has all sorts in it. The difference in atomic number drives this. It’s a very clear differentiation on an X-ray image,” says Richard.
The sensitivity of the machines is remarkable.
“Our technology is designed to cope with thousands of items a minute as they reach the end of the production line – yet still identify a tiny 2mm fragment of bone in a piece of chicken, for example, and ensure that particular item is rejected and reworked before the products are packaged. The same technology can also check the dose level of powdered drugs or detect small air bubbles in vials of liquid medication.”
The accuracy comes from the combination of signal processing, machine learning and the underlying adaptive algorithms examining the statistical distribution of features in an image as it is captured by the detection equipment.
“We have some very nice algorithms, but we also have other techniques,” reveals Richard.
“For example, because chicken bones are very light and difficult to detect, we’ve borrowed a technique from the medical industry called DEXA or dual-energy X-ray absorptiometry that we use.
“We have very high resolution systems directed towards finding fish bones in fish. A fish bone can be very thin – less than a quarter of a millimetre in diameter – and this requires much higher resolution.
“In other areas, we use multiple X-ray beams, particularly when we are looking at glass shards. One of our specialities is finding glass in glass – a shard of glass in a jam jar, for example. Each one uses a different trick. We are a bunch of techies and we love doing new stuff.”
But is there any danger or impact on products when they are X-rayed?
“In the very early days, there were concerns from pharmaceutical companies that an X-ray would affect the efficacy of a drug, but we’ve been through many, many trials over a 30-year period that shows there are no negative effects. It is incredibly low levels being used,” explains Richard. “The major food and pharmaceutical companies are very large vendors and have been through their due diligence.”
With the technology proven, demand is now growing fast.
“Product recalls due to contamination are expensive – not only in terms of disruption to supplies but also because of the potential damage to a brand as a result of negative publicity surrounding such an incident. So manufacturers are under increasing pressure to ensure they spot any issues before products leave the factory,” says Richard.
“One of our classic applications is for Kit Kat. If you have a Kit Kat with a missing wafer you end up with a solid chocolate finger, which is absolutely wonderful, but chocolate is so much more expensive than the wafer, so that costs the manufacturer – Nestle in this country and Hersche in the States – a fortune. Kit Kats are produced in very high numbers, between 4,000 and 8,000 a minute on a single production line.
“We inspect every single one of those, spot the one with the broken or missing wafer, knock it out. They melt the chocolate and reuse it.”
From ready-meals to cakes, the food industry uses the technology to inspect all kinds of products.
“One of our areas of specialisation is measuring the amount of fat in meat,” adds Richard. “If you are a meat processor and you want to sell to McDonald’s you have to guarantee there’s no more than 20 per cent fat. This is a means of establishing that.
“Sometimes, there may be a restriction on the amount of non-meat in a sausage.”
The company’s growth is also being driven by pharmaceutical and cosmetic applications.
“We inspect insulin pumps to detect if they are correctly assembled at a rate of up to 30 a minute,” says Richard.
“These are complex devices and there are a new breed of low-cost insulin pumps. Originally pumps were expensive and reserved for type-1 diabetics.
“Now instead of several thousand dollars, they can produce one for three or four, so they can afford to provide these to some type-2 diabetics.”
With diabetes rates rising sharply – there are 110 million living with the condition in China – the demand for this technology is growing.
Likewise, pharma companies use the machines to inspect dosing in powder inhalers.
And it can inspect liquid medicines for tiny gas bubbles.
“We do quite a lot of bubble detection in the cosmetics industry too,” adds Richard. “If you have an applicator device with a bubble in the wrong place it won’t work.”
It is the latest success story in an intriguing career for Richard, a William Pitt Fellow at Pembroke College Cambridge, who began by making amplifiers for college friends before establishing Pace Group to sell professional audio equipment and undertake specialist electronics work for the likes of Emerson Lake and Palmer, Led Zeppelin, Genesis, Yes, and Deep Purple.
He founded AVS in 1982, initially as a microprocessor consultancy, but it quickly focussed on automatic inspection technologies using high-precision measurement and statistical process control before diversifying into vision systems and X-ray components.
AVS developed a vision system for cereal giant Kellogg’s in 1985 and began selling directly to companies. The company was responsible for the first ‘glass in glass’ detection system in 1992 and developed in-line fat analysis in 1997, before being acquired by Mettler Toledo Safeline.
Richard spent three years there before founding Cheyney Design.
The company is now busy recruiting signal processing, machine learning and algorithm experts, as well as other roles such as electrical engineers and business developers to help grow its customer base – which already numbers 200 around the world.
Customers can buy the machines, kits and components, and there is a rental facility.
“We started selling technology kits in 2005 and in 2015 we migrated towards selling systems so we’re still on a growing trajectory,” says Richard. “We sell machines around the world. We’re just building one that is going to the Ivory Coast. We have a number of machines in Madagascar.
“We still supply kits to OEM customers – we have customers in Holland and Germany who buy them from us. In particular, we’re growing the systems business.”
And there’s every sign that Cheyney will succeed in doing so.
More by this authorPaul Brackley