A monobloc concept for the dry end

The field-proven technology of monobloc machine synchronisation can now be used for packaging functions as well: Krones has also come up with a monobloc solution for the dry end. The Ergobloc D (for Dry) combines field-proven standard machines with innovative new designs to create a holistically harmonised system for end-of-the-line packaging and palletising. It can be used for canning lines, non-returnable-glass lines and non-returnable-PET lines in all speed categories.

The concept’s aims were many and varied, and all of them have been achieved. By reducing non-value-creative functions like conveyors as buffers, the footprint has been concomitantly downsized, since now it only has to accommodate the truly functional units. This also signifies less legwork for the operators, who additionally benefit from the holistic human engineering provided. All machines operate with the same harmonised control and drive concepts. In conjunction with the intelligent line control system and the monobloc synchronisation provided, continuously uninterrupted operation is assured. Taken together, all these points mean enhanced line efficiency, reduced energy consumption thanks to dynamic machine response capabilities and optimised spare parts inventories.

A direct comparison with the line layout of a conventional dry end immediately reveals significant space savings. The Ergobloc D combines the following concatenated components: a Variopac Pro packer in one of its variants with a downstream shrink tunnel, a short Accucase pack conveyor, followed by a Robobox pack grouping system with the appropriate palletiser from the Modulpal range complete with a layer pad handling feature.

For integration into the Ergobloc D, the Variopac Pro has been given another comprehensive revamp, designed to maximise its dependability. Operator friendliness and operating characteristics, for instance, have been further improved by a series of modifications. These include a design-enhanced container infeed with optimised accessibility, now also suitable for mass transport of lightweight containers. Changeover times have been cut, thanks not least to setting gauges, with concomitant gains in terms of setting reproducibility. This provides enhanced flexibility. For pressureless infeed of ‘soft’ containers, an individual-drive station has been integrated, featuring SEW-Movigear technology. In order to assure dependable transport of large-size containers, two lanes can be used in parallel. For changing over to different containers, there is no need for sensor height adjustment; the only setting that requires re-adjusting is the width. All this provides maximised reliability when handling soft or lightweight bottles.

The film wrapping station is height adjustable, so there is no need to replace the tuck-in bars. In the film-cutting module, operating characteristics have been improved by modifications like using profiled draw-in rollers, which reduces soiling of the rollers with printing ink or film constituents. The cutting blade, too, has been equipped with a servo-drive, so that now, for instance, thinner films can be used, down to 25 µm for 0.5 L sixpacks. This changeover to servo-blades is also possible as a retrofit upgrade for existing Variopac Pro machines. Thinner films contribute towards savings in material costs, and also improve machine availability, since fewer rolls of film have to be fed in. Thus a three-shift line, for example, running at 43,200 bottles an hour, can be changed over from 60 µm film to 27 µm film, enabling annual cost savings in the six-figure range to be achieved.

Insertion of the film reels in the automatic splicer has also been human engineered for enhanced convenience. Quick-change handling parts ensure swift machine restarts. All production parameters are set from a centrally located control panel, featuring a 38 cm touch screen.

In the new shrink tunnel, air distribution has been further improved by providing adjustable shaft partition walls. An optimised temperature control feature has cut energy consumption by about 15% compared to the previous design. The partition walls can be adjusted to accommodate single-lane, double-lane or triple-lane pack transit.

Thanks to the numerous improvements in the design details of the Variopac Pro and the shrink tunnel, a longer useful lifetime, higher levels of availability and enhanced functional dependability is being predicted for the machine, while by virtue of its modularised concept it remains flexible for handling any new types of packaging in the future.

Depending on the rated output of the Variopac Pro involved, the downstream Accucase modularised pack conveyor can be provided in one or two lanes, in units of eight, 12 or 16 metres. This pack conveyor route serves for emptying the shrink tunnel in the event of a malfunction.

The Modulpal system was conceived as the successor generation to Krones’ Pressant Universal twin-column palletiser family. The palletisers utilise a shutter-type gripper head with a servo-drive and automatic layer centring, and provide high loading capacities. The Modulpal 1 ADR single-column robot used for palletising in the Ergobloc D, for example, replaces the previous Pressant Universal Duplex twin-column palletiser. Where the high speeds used to necessitate a high-level pack infeed, the Modulpal 1 ADR is now content with a low-level pack infeed. Besides the high speeds it reaches, this machine also scores in terms of its high carrying capacity of twice 700 kg. Its new features include a layer pad insertion system that places the layer pads underneath the Modulpal’s shutter-type gripper head, thus enabling layer pads to be inserted even at high speeds without any loss in performance.

Thanks to the multifarious options it offers, the Modulpal enables special wishes of the clients involved to be met, with a compactly dimensioned footprint and multifunctional applications. Servomotors ensure good dynamic response and minimised maintenance outlay. Using the modularised system and standard drives also downsizes the spares inventory requirement.

Upstream of the Modulpal is the Robobox pack grouping station, featuring definite advantages that many clients have already found persuasive. It scores particularly high marks in terms of reliability. Positive turning of the packs on a flush-grid-belt conveyor also assures dependable handling of critical packs, like shrink-packs holding containers with a petaloid base. Nor do ‘still’ products constitute a problem for the Robobox. No handling parts whatever are required, like spacing devices. The Robobox creates maximised flexibility for layer preparation, coping effortlessly with high speeds. Depending on the upstream Variopac Pro, the packs can enter the Robobox in either one or two lanes. If one module fails, the other module can continue production at a lower speed. The individual turning units have been weight optimised and provided with collision guards.

For the Ergobloc D, Krones has also comprehensively design enhanced the layer pad insertion system. Two systems have been developed for automated layer pad supply - the first one for handling flat layer pads and the second one for reel-fed layer pads. The pads themselves are fed in below the shutter-type gripper head, thus eliminating any time losses when fitting a base pad. This new design for handling the packaging aids involved saves on expensive floor area, in many cases requires merely a single inserter even at high speeds and thus makes for a concomitantly reduced amount of capital investment.

All that’s needed for operating the entire palletising system is a 38 cm colour touch screen as a control panel, which, with a visualisation feature for the currently active layer patterns, also indicates remedial action for possible problems.

A comparison with conventional packing/palletising systems shows that the Ergobloc D possesses a high potential for saving on hall space, something that is also gratifyingly reflected in the capital investment costs.

By Wolfgang Huber, Krones AG, Rosenheim, Germany