It's chocs away as flexibility takes flight

28-Mar-2006 - Last updated on 13-Mar-2017 at 21:26 GMT

New research aims to develop packaging machinery that combines automation with flexibility, as John Dunn discovers

Master of the mint chocolate, Bendicks of Mayfair, likes to describe its confections as "the chocolates with a touch more thought". But the 75 year-old Winchester company is also putting a touch more thought into the way its chocolates are packaged.

Bendicks is part of a UK university-industry research project to develop flexible packaging machinery to automatically fold, erect and fill a wide range of different confectionery boxes.

Every time someone like Bendicks comes up with a new marketing idea for celebrating Valentine's Day or Mother's Day with chocolates, they usually want a whizzy new carton design.

At the moment it is usually human beings who have to deal with these "origami boxes", bending and folding the bits of cardboard, putting the chocolates in, and sealing up the cartons. And it could take operators days to learn how to do the job and get up to speed -- by which time Mother's Day will have come and gone for another year.

Not to mention the fact that cardboard tears and its sharp edges can cut fingers, creating a lot of wastage and scrap, particularly if a line has to be stopped and cleaned down after a cut.

So what Bendicks and Marks and Spencer, its partner in the Food Link project, are both hoping is that research at Bath University and King's College London, with help from packaging machinery group Field, will lead to the development of an automatically reconfigurable confectionery handling and packaging system (ARCHAPS).

The idea is that the machine will use automatically changeable linkages or mechanisms to hold and crease the pre-cut pre-printed cardboard blanks. Clever robotic fingers will then prod the cartons in the right places to push them into shape and close the lid once they have been filled.

The idea of a flexible packaging machine for chocolates that could reconfigure itself automatically for different shapes and sizes of carton began about 10 years ago. Dr Jian Dai, who heads the Link ARCHAPS project at King's College London, was working for Unilever's research labs at Port Sunlight. It was the Elizabeth Arden range of cosmetics that was causing Unilever grief.

"There was constant innovation and packs and cartons were constantly changing," says Dai. But the packaging machines could not cope. "They could handle slight changes in size, but if we wanted to change a carton from a hexagon to an octagon it was impossible without expensive tooling changes." And so Unilever relied on manual handling for packing its cosmetics.

So Dai developed a reconfigurable, dextrous assembly and packaging rig based on the invention of 'metamorphic mechanisms' -- linkages that can automatically change their shape and their number of degrees of freedom for different tasks. From there he went on to develop a reprogrammable robotic finger that can push a carton into shape and tuck it closed.

Confectionery challenge

The principle of a reconfigurable machine for product handling and packaging has been demonstrated for cosmetics, says Dai. The challenge now is to make it work for confectionery with all the added complications of hygiene and product fragility.

"The aim of the project is to see whether we can use the finger technique to put chocolate boxes together in small runs," says Dr Glen Mullineux at Bath University, which is contributing its expertise in constraint modelling on packing machinery. "We have identified two or three of the motions that are required and we've currently two designs -- one is a finger to do a pushing and closing operation and the other is a folder to do gross, extended creases. Now we are trying to put these two together and build a test rig."

Choccy companies are not the only food makers to be frustrated at the way their products are packaged. The sealing of ready meals into microwaveable plastic trays is also fraught with problems. The machines are inflexible -- you have to stop the machine and change the tooling every time you want to seal a different size tray. The sealing film can tear, the knives that cut the film can leave a tray stuck to the film instead, and seals aren't always perfect, with meals leaking on the supermarket shelf.

But Grantham-based The Recipe Company, part of Northern Foods, has been trying out a prototype tray sealing machine that uses a computer-controlled laser to seal and cut the film. An automated camera vision system then does a 100% check on the seals.

The work is the result of another Food Link project involving, among others, Northern Foods, machinery maker Packaging Automation and Loughborough University. Packaging Automation hopes to have a commercial laser-based tray sealing machine on the market in a year or so and Loughborough University is in talks to get its patented vision system on to the market in the near future, initially as an add-on for conventional tray sealing machines.

Machines that talk to each other

But if you are being hammered by Tesco to double your output, then you can probably live with your existing cartoning and tray sealing machines. What you can't live with is not knowing exactly what is happening on your factory floor. If you don't know what your packaging machines get up to all day, how can you eliminate the bottlenecks and speed up production?

The problem is that packaging machines don't talk to each other. There is no common language that allows equipment from different manufacturers to talk to each other and to allow human beings to interrogate them easily to find out what they've been up to.

Common language, data communications protocol, user interface standards, control software, fieldbus -- call it what you like, but there is nothing common about the way packaging kit is programmed and controlled.

But all that is about to change. Many of the major global fast moving consumer goods groups such as Arla, Nestlé, Unilever and Procter & Gamble, are fed up with this lack of commonality.

Five years ago they got together in the US to push the packaging machinery builders into harmonising the way machines were controlled and interfaced. PackML was the result -- if packaging machinery could talk, then PackML would be their language.

A year ago, PackML came under the wing of the US's Instrumentation, Systems and Automation society (ISA) and it is now being developed into a formal standard, Make2Pack. This is based on ISA's successful communication standard, S88, for batch processing operations (see Food Manufacture's Food & Drink Processing Equipment supplement, February 2005, p4).

The major automation suppliers are now actively implementing Make2Pack in their control systems. There are benefits all round -- better overall equipment effectiveness and control for food manufacturers and faster systems development for machine builders.

In the Tower of Babel that is packaging machinery control today, PackML is fast becoming the dominant language. It is the only way a machine can explain to the outside world what it is doing, says John Pritchard, European product manager for motion systems at automation supplier Rockwell, which has been heavily involved in developing the standard.

Today, says Pritchard, food companies have to be agile. And to do that they need a good grip on what's going on the factory floor.

"The nirvana is where all machines speak a common language and are networked together so that they can share information about what they are up to, " he says. "But also with PackML you can sit in your office and poll each machine and gather data about what's going on and understand your manufacturing."

"One thing is for sure. If you are a packaging machine builder and you want to sell to someone like Unilever, then you have to implement PackML," he adds.

"And if you are a food company using packaging machinery, then you should be thinking about getting your suppliers to implement it because the big companies have proved there are lots of benefits." FM