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State of the PET-bottling art

With the use of newly supplied equipment, Vitaqua is producing around 60 different beverages in one plant.

Each line of Vitaqua’s Breuna facility, in Germany’s Hasse region, possesses its own Contiform S24 blow-moulding machine, and is rated at 43,200 containers per hour. Two of the lines handle solely 1.5L PET containers, making for a very high bottling volume per line of 64,800L per hour.

The strict focus on 1.5L containers significantly increases line availability, because no machine needs a make-ready routine, except the blow-moulder. Changing this latter over to a different bottle shape, which is necessary up to three times a week, takes just over one hour. The third line is able to process both 1.5L and 0.5L containers.

The relatively lightweight 0.5L non-returnable PET bottle, developed in-house at Vitaqua, is the only one produced and filled on the fourth bottling line. Its new Shorty neck finish made a substantial contribution towards reducing the bottle weight from more than 20g to under 14g. This means that despite its lower weight this bottle, with its petaloid base, remains dimensionally stable even when being filled with carbonated beverages.

According to the company, the Contiform machines possess an automatic adjustment system for the preform mandrel, whose lowering feature enables the 300 preform mandrels in each oven to be changed over from a Standard Alaska 267 to a Shorty neck finish at the touch of a button, allowing enormous time savings for change-overs.

All the Contiform machines are equipped with the Air Wizard I and II energy-saving modules for reducing the dead-space volume and the final blow-moulding pressure. Vitaqua also insisted on having the Air Wizard III module, which serves to feed any superfluous final blow-moulding air back into the compressor.

Thanks to this module, a smaller compressor could be chosen, thus saving on investment and operating costs, as well as further downsizing overall energy consumption. The preform feed function is likewise fully automatic, with electric overhead conveyors taking pallets of preforms to individual machines, where they are loaded into the preform feed unit.

Maximised filling accuracy

AirCo conveyors take the sterile containers to the filler hall. Each blow-moulding machine has been assigned one bottling line, with no crossover configuration planned, decreasing malfunction risks.

The four Volumetic VODM fillers have been designed as Modulfills, with Monotec columns, without front tables, and dimensioned for the above-mentioned high speeds with 1.5L containers. The filling valves are likewise able to handle both containers with a Standard Alaska 267 and with a Shorty neck finish. “Of course, filling accuracy is a crucial factor for us: we’re talking serious money here,” said plant manager, Ronald Göring.

Each filler is covered by a cleanroom roof and enclosed, producing Cleanroom Class 1000 and thus satisfying the most stringent of hygienic requirements. Aseptic servo-closers apply the screw-caps with maximised precision, while Checkmat FM+K+L machines use a camera system to make sure that the fill level specified is accurately complied with and that the containers are being properly capped.

The four Contiroll HS Highspeed labellers are of identical construction, each featuring two stations which ensure reliable, smooth running. The fact that each individual station’s speed is concomitantly moderate, meaning nowhere near the limit range, makes for low-wear, low-maintenance operation.

Each line boasts two generously dimensioned Accutable buffers, providing a sufficiently long buffering time between the filler and the labeller, and between the labeller and the packer, thus avoiding stop-and-go operation and contributing towards enhanced efficiency levels. “What’s also important for us is the first in first-out principle – you won’t find any fallen-over bottles here,” said Göring.

Dependable design

The Variopac Pro FS non-returnables packers, with their new bottle infeed, are also suitable for still beverages with pressureless bottles. For two-lane handling, a shaft wall in the form of a perforated hollow chamber has now been inserted in between the two packs as well, producing a direct flow of hot air into the packs in order to ensure a very high-quality shrink-wrap result. This enables energy consumption to be reduced by about 20%.

In order to avoid a high back-up pressure in the packer’s infeed, bottles are passed into the machine through a single-lane drive, providing advantages for still beverages, in particular. Another electric overhead conveyor has been installed between the wet and dry ends, supplying both with requisite operating materials. At the same time line pallets whose loads have only been partly used up are also removed.

Once six containers at a time have been shrink-wrapped and the shrink-packs given a handle in the Variopac Pro packers, they are loaded on retailer-friendly half-pallets, and placed on one europallet, two at a time. This task is handled by two Modulpal 1A palletisers each, with a high-level infeed. These machines possess a newly designed infeed unit where grouping is performed on a flush-grid belt. The packs are positively turned and handled with maximised gentleness.

“This is important for pallet stability. It means we’ve got to wrap the pallet in less film, and that makes a big difference,” Göring said. The lines have been designed to be run with a low staffing level. All four blow-moulders are located in a separate hall and operated by just one person.

The price for this was doing without a blow-moulder/filler BLOC configuration. Each pair of lines has been erected in a mirror-image layout, so two fillers and two labellers are positioned relatively close together and can likewise be operated by only one person.

The integrated LMS line management system, which writes the order from the production schedule onto the machine concerned in each case, permits on the fly changeover routines. The operator is informed in good time of what task needs to be performed next, and so can prepare for the next order. While the filler is still producing, the blow-moulder can already be prepared for product change-over. This concept is reflected throughout the line.

“This makes for much more effective line utilisation,” said Göring. “Running a line until it’s completely empty will take about 40 minutes. And we can almost make up all this time with our on the fly changeover routines.

“We’re significantly further along than I had ever dared to hope. Normally, when you embark on a project as comprehensive as this one, you’ll be confronted with a completely different set of problems. But this all went pretty well,” concluded Göring.

— Roland Ruckriegel is the area sales director at Krones.

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