ProSweets Cologne 2009: packaging of confectionery

Champagne truffles, almond slivers or nougat hearts - the assortment of pralines seems unending, and those who enjoy the noble treats value a certain amount of variety in the usually elaborately designed packaging. But how do these sweet products end up in exactly the right place in the packaging? Previously this was only possible through manual labour. However, these days robots can sort the products into trays - quickly, flexibly and hygienically. ProSweets Cologne, the supplier trade fair for the confectionary industry from 1st to 4th February 2009 will present the latest packaging trends for the confectionary industry.

The trade has been calling for the increase of mixed packaging, not only with pralines and fine backed goods, but with all kinds of bakery and confectionery products, as space on the shelves is limited and consumers value variety. What's more, the rapidly changing packaging units and a trend towards seasonal packaging cry out for flexible solutions in packaging technology. This is where the robot comes in. Until now, only primary and secondary packaging processes were carried out by robots, with only the occasional exception.

From now on this is going to change, and top loaders especially will grow in importance. They generally comprise various pick-and-place robots, a product feed and a module for feeding the packaging - dishes, trays or cartons, for example. Product and packaging positions are continually registered and calculated using image recognition so that the robot can grip the correct product and place it precisely at the correct spot in the packaging. The filled blister or tray is then transported further, where either conventional packaging machines or robot modules take over the process of cartoning the products.

Top loaders offer several advantages. They can be adapted to the exact available space of the company and are increasingly popular in production halls, where space is becoming scarcer, as they don't take up much room compared to conventional packaging systems or manual packaging. This has led to an enormous growth being recorded over the past few years in the area of pick-and-place robots. This segment is growing at a rate of around 15 per cent every year, and experts expect it to continue to grow in the future.

Products are mimosas
Sweet products that are to be packaged often have to be handled extremely carefully, which is why flexible vacuum suction cups that can be used on various baked products or praline forms and surfaces are fitted, as they can pick the products up from the belt and place them into the packaging. One only has to think of extremely fragile wafer thin biscuits, vanilla crescents coated with a fine dusting of icing sugar, or exquisite pralines, which require especially delicate handling.

For all these products, special grips have been developed. For example, vanilla crescents are held by a grip with small rubber fingers. These fingers are attached to a membrane, which, depending on the internal pressure, bends outwards or inwards, and so opens or closes the fingers. Thanks to this principle, the gripping force is evenly distributed among all the fingers. A deciding factor when choosing a gripper is if it complies with the hygiene standards set for food processing. This is why, in general, only rust-free or plastic materials are used, as they are easy to clean and don't accumulate any residues.

Especially in the area of grips, much research is being done. The goal is to recreate the sensitivity and flexibility of the human hand. At the Courant Institute of the New York University, an adjustable gripper has been developed that reacts to impulses it receives through integrated sensors, and changes its grip accordingly, in the same way a human hand would. NASA too has developed a so-called "conforming gripper", which was originally to be used on missions to the moon. It works by using pins that gently flex to accommodate the form of any object, and therefore effectively eliminates the need for a wide range of specialised grips for different operations.

Positioning and controlling
Image processing is a central element of the pickers. It recognises and calculates the position of the product which is to be packaged and that of the trays or dishes. Control software has all the combinations of products and blisters recorded. It determines which robot will place which product into which position. So that all robots know where a product has to be placed and which blisters still have to be filled, they communicate with each other through a central controller. In addition, the image processing also takes care of the quality control. A new reflected light scanner can not only recognise surfaces in square millimetres, geometry and orientation, but also cracks, colours and blotches. This means the products can be checked for faults and if they are all there and placed correctly in the tray.

Simple, quick and flexible
Through the use of lightweight components, the speeds that are needed in the area of packaging can be reached, because the smaller the mass involved, the more dynamically the robot can work. Depending on the size and weight of the product that is to be handled, speeds of 150 pick-and-places can be reached per minute.

In addition to speed, another requirement is flexibility, as this makes it possible to adjust to a new product or a new packaging format in the shortest time possible. This calls for automation solutions which can be adjusted at the touch of a button. Manufacturers of top loader facilities are currently working on a automatic tool change. A manufacturer of packaging machines is offering a tool magazine for a top loader, in which various tools have a base station for the different formats. When there is a change in format, the robot "parks" the non-required tool fully automatically into the tool magazine and grips the new tool. It can then continue to operate. The innovation will guaranty a fast and prompt change of format, as well as the safe storage of the tools.

Another manufacturer of packaging machines is presenting a non-contact control connection between the tools and the robots. When it's time for a change in tools, no plugs have to pulled out or plugged into the socket. This saves on average six to eight minutes in change-over time.

Thanks to the systems' flexibility, confectionary producers can react much more flexibly to seasonal load fluctuations. For example, when Easter bunnies are needed instead of Santa Clauses, the machines can quickly be retooled. This means there are no problems if there is a summer break in praline production.

Even ties ribbons
To conclude we would like to refer to a feasibility study, which was undertaken by the Fraunhofer IPA Stuttgart for a praline producer. The goal was to test if a robot is capable of tying a ribbon around a box of pralines, a task which demands a certain degree of coordination from humans. The use of a second robot or a image processing system was not allowed. The result: The robot can tie the ribbon - and this, so to speak, blindly and single-handedly. However, the box and ribbon have to be fed manually.

In cooperation with the International Sweets and Biscuits Fair - ISM - ProSweets Cologne presents the confectionery industry's entire value chain at one trade fair location, from individual raw ingredients and process and packaging technology to the packaging itself and the product ready for retail sale.

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