Variety in the sweet shop

As in many areas, the rise of “retail power” has brought about intense rivalry in most sectors of the confectionery industry. Suppliers have been pressurised into hitherto undreamed of economies affecting each individual product, the way it is made and the way it is packed – all at a time when the product offering is increasing in complexity.

Historically, the market was less volatile. Machinery could run continuously for long periods without being affected by changes of product size or shape, or, more significantly, marketing influences affecting the packaging, which is driven so hard by retail promotions.

To produce confectionery in the variety of sizes and packaging demanded by today’s market calls for far greater flexibility where machinery is concerned. A happy plant manager is one that controls lines of modular plant that utilises an optimum footprint, produces shorter runs of product cost effectively, is quickly and easily adapted, can be operated electronically from one source and requires the minimum of maintenance.

Indeed, the combination of PC controls and machine modularity has brought customisation within the reach of some, but at a price. Capital investment in modern machinery is largely restricted to the big brands. Elsewhere second hand machinery is finding increasing use by own-label suppliers where competition is increasingly cut throat.

Similar problems face contract packers, many of which operate on behalf of the big brands. They, too, will take on the “scrap heap challenge” rather than risk heavy capital investment on a contract that may have a limited life.

But while second hand and modified machinery often provides the only solution to an engineering problem, a solution that is economically viable, the latest equipment is more likely to meet “world class” requirements.

The use of new or second hand machinery is largely governed by market conditions and players’ demands within that market, import duties and the degree of sophistication in each market. This is unlikely to change in the short term although escalating EC electrical and mechanical regulations may force the pace at which new machinery is replaced for old.

The latest top load carton forming and closing affords the end user increased packaging efficiencies by loading the product through the widest possible opening. Among recent top load cartoning projects have been two lines for Nestlé France, to handle wrapped chocolate Lion Bars.

Speed is up to 120 cartons/min, with two sizes per line. The three-flap charlotte style carton is lock erected and hot-melt closed. The lines each use a Kliklok SRW double headed forming machine to lock form two cartons at each stroke, depositing them into a flighted conveyor.

These machines are interfaced with an existing automatic loading system, which places the bars in the required count into the erected cartons. After filling, the cartons are closed using the Kliklok Mini Genesis Closer, a small footprint machine able to handle cartons arriving at random.

Individual chocolates are fragile items and require very careful packing – a challenging task for Gerhard-Schubert’s TLM top loading machines. When designing the TLM, Schubert turned to mother nature for inspiration, using the human hand as the role model. The robot’s arms are controlled by a vision system and can, therefore, distinguish between 12 different chocolates. Most impressive is the delicacy with which the chocolates are handled.

Movable robot arms are suspended in the top section. All the motors installed in the equipment are speed-controlled. The drive technology, including Lenze 8200 vector frequency inverters to drive the conveyors, is networked via PROFIBUS and CAN interfaces.

The controls are found in the top of the machine, allowing best possible access to all the moving parts, while the packing is done below. A top-loading machine erects a carton from flat blanks, takes the product from the conveyor belt, places it into its packaging and seals it.

A Schubert TLM-F44 machine has recently been installed at Thorntons to pack the company’s famous Continental range at speeds up to 900 chocolates/min in a round-the-clock operation at its plant in Alfreton, Derbyshire, UK. This line also has a Schubert vision system to check the quality on each of the chocolates packed and that each tray is correctly filled. A TLM F2 robotic de-nesting facility places trays onto a product loading conveying system and a series of four axis robots each pick and place 90 chocolates/min into trays.

Also on a three-shift programme at the Alfreton plant are two a further two Schubert systems packing chocolate bars and bars of toffee into cartons.

“We have chosen Schubert to supply a number of automated packaging systems because of their ability to produce high performance and reliable equipment that can meet the demands of our three-shift operation”, says John Chambers, Quality and Improvements manager at Thorntons. “We have also been impressed because they have helped lower our production costs and further improve output,” he added.

Meanwhile Bradman Lake has developed an automated system for collating and packing flow-wrapped cereal and other confectionery bars into end load cartons. Until now, producing count-line packs of wrapped cereal bars in volume required a carton erector, robotic top loader and 3-flap carton closer. In contrast, the Bradman Lake Racetrack cartoner collates product, erects, loads and seals endload cartons at speeds of 350-400 bars/min in a single machine unit.

The Racetrack collator/loader has twin servo-driven belts, each with nine pockets, which can deliver various product counts, including layers, to a synchronised indexing motion SL902 carton end loader.

Cartons from a motorised magazine are erected by a triple-head rotary feeder and loaded into the pocketed infeed conveyor of the indexing SL902 by a compact overhead pusher unit, also servo-driven and triple-headed. The bars are then loaded into the erected cartons during the stationary phase of the cycle by a second overhead pusher, replacing the extended barrel loader section used in many continuous motion end loaders.

Wrapping confectionery is an art. Over time many wrapping technologies have been developed to accomplish the industry’s understandable demand for optimum brand impact on shelf. For those that favour shrinkwrap, the Sealed Air Corporation’s Opti 4500 automatic L-sealer, with packaging speeds of 25-35 packs/min, has 10 programmable pre-sets that increase the flexibility and speed of package changeovers. Vertical and horizontal sensors facilitate proper product spacing on the production line and, with the ‘hot knife jaw’, strong and secure seal strength.

The system is outfitted with a film reverse mechanism that relaxes the film during sealing, creating stronger seals for high profile products over 10cm in height. Pin perforators with brush rollers maximise air evacuation and product appearance, while the safety locks feature is designed to assure operator safety. The Opti 4500 also has a recessed film cradle making it space efficient.

While shrinkwrapping is definitely suited to secondary packaging, it does have its limitations – the product it is enveloping can be damaged as it passes through that essential component part of the process, the shrink oven.

The shrinkwrapper is a workhorse, ideally suited to transit and multi-pack packaging and reducing the length of shrink tunnels in recent years has made it even more cost-effective. Shrinkwrap machinery is relatively inexpensive and takes a range of pack sizes. It is a very forgiving discipline, unlike the overwrapper, which requires fresh adjustment every time the operator changes pack size. Yet, the overwrapper will always provide a neater wrap. That is why confectionery suppliers use overwrappers in abundance.

Marden Edwards make overwrappers to wrap chocolate boxes for Nestlé, Duc D’O, Guylain, and Fazer, among others. It has also provided systems for high speed individual and multi-pack wrapping of the popular ‘Z click’ style packs as well as open top confectionery distribution packs.

“One of the reasons why confectioners utilise the envelope wrap is primarily for presentation and marketing,” says Marden Edwards marketing director Jeremy Marden. “With polypropylene you get a high-shine clear wrap that gives the appearance of being hand wrapped, whereas with a traditional shrink wrap you get less clarity, a perforated film to allow the large amount of shrink required and a bead seal around three sides of the pack.

“Chocolates are very sensitive to heat and an over-wrapper only uses quick instantaneous heat to seal the film join and there are no tunnels needed to shrink the film. Other advantages are that a near hermetic seal is produced, tear tape can be used for easy opening and polypropylene film can have a cost advantage over polyolefin, which is used for shrinkwrapping.”

If a shrink-wrap appearance is desired together with benefits of over-wrap, Marden Edwards has recently introduced a shrink tidier machine. This can be freestanding or integrated into an overwrapping machine and is a compact method of achieving a skin-tight wrap for an envelope end fold presentation.

The shrink tidier consists of heated top and bottom continuously moving belts. Using new polypropylene films with shrink properties, it gently shrinks the film around the pack without distorting the tear tape and without damaging the contents.

Good presentation on shelf is critical. That is why Troll-Gott Konfektyr AB, a Swedish confectionery company, uses an Ishida Flexible Packaging System (FPS) to present its retail customers with ready-to-use display cartons in which every bag is neatly ordered and correctly orientated. The system has increased packing speeds by up to 80%, while saving the labour costs associated with two manual packers. At the heart of the system is a 3-axis, servo-controlled, pick-and-place casepacker.

Ishida was asked to provide a complete packing line downstream of the bagmaker which would not only orientate, checkweigh and metal-check the bags, but also erect and position the cases, fill and seal them and transport them to the palletising system.

One challenge that confronted Ishida was preventing the pillow bags of confectionery from emerging upside down from the vertical bag-maker. To turn the bags over before the case-packing operation, it designed a special re-orientation unit that flips the bags forward. The re-orientated bags are moved, through an inclined conveyor and a checkweigher with integrated metal detector, to the FPS. Here, a preset number of bags are collated. The FPS then picks up two collations and places them neatly into a display case, repeating the operation until the case is full.

In recent years, users who wanted to reduce footprint have been forced to turn to stretchwrap, but the technology has advanced inordinately. With a stretchwrapper, the film is stretched around the pack and the sealing jaws meet in the middle. Cams and material release equipment govern the amount of stretch on a film, providing substantial savings over shrinkwrap.

The stretchwrapper generally offers a higher specification all round – build quality, the technology of the film it uses, the unwind and cam systems on the pre-stretch of the film. That is why a stretchwrapper tends to cost 25-30% more, but stretchwrap will always be the chosen technology for some customers and there has been a swing to stretch over shrink.

Branding has posed a problem to stretchwrapping in the past but, with more sophisticated technologies, these problems have been largely eradicated. The brand name or message can now be shrunk in perfect alignment by using a

PE film that will only stretch or shrink in one direction. Today’s suppliers of PE can actually control how the film shrinks and in what direction it shrinks. Once shrunk, a film can shrink no further and is ready for printing.

Most manufacturers use PLC controls now. Timers and relays have long since become a thing of the past and component parts of both shrink and stretch machinery have been reduced considerably. One would assume that, because of this, such machinery is easier and cheaper to produce.

It is but, with the arrival of the computer, comes the programing of each machine. Capital equipment of this type has to be individually programed with different timing settings, speed outputs, single and dual pusher systems, synchronisation and so on and this does not come cheap.