DRINKTEC REVIEW PETplanet Insider Vol. 23 No. 12/22 www.petpla.net 30 100,000 PET water bottles in one hour Whether it’s climate change, supplying the world’s population with enough food and drink, or responsible stewardship of packaging materials, humankind is currently facing major challenges which are also impacting the food and beverage industries. In Krones’ view, PET can help solve some of the pressing issues of our era. After all, this type of packaging can be sustainable – provided, of course, the process for producing the material is resourceeconomical and a closed cycle is maintained. In order to meet the rising demand for packaged water, filling companies need appropriate machine speeds. Contrary to commonly held opinion, a single larger line offers better performance in terms of both energy and media consumption per packaged unit than multiple medium-output lines. Krones’ response to this development with the first wet-end block achieving an output of 100,000 0.5 l water bottles per hour. The basic production sequence of this 100,000 bph block is the same as in a conventional ErgoBloc L. The preform feed unit passes the PET preforms into the Contiform 3 Speed stretch blow-moulding machine. With a rating of 2,750 containers per blowing station, it set new benchmarks for output and compressed-air consumption. In order to cope with the high output of the stretch blow-moulder, some additional, optimised components, functionalities and assemblies were incorporated in the Ergomodul. For example, the two Contiroll stations and the Multireel magazines for label reels feature a new buffer system which keeps the label tension at a constant maximum level, thus offering ideal preconditions for thin label films, a boon for sustainability. Another of the machine’s key features is the “no bottle – no label” function. If a service rejection in the blow-moulder causes a gap in the bottle flow entering the labeller, no label is transferred to the vacuum cylinder and the corresponding vacuum cylinder suction bars are retracted upon reaching the glueing unit. As a result, no label or glue is wasted and any gaps in the container flow no longer affect the efficiency of the line. Two filling units, two closing units – one machine The filler posed the biggest challenge for the development team because there are physical limits to the standard approach of “bigger carousel equals higher output”. At some point, the masses to be moved and the forces acting on them simply get too big to reliably maintain a stable process. To prevent this, the block features two modularised filling units and closing units. That may sound simple but was in fact difficult to implement because although the filling/closing of 100,000 bph is evenly distributed among two units each, these units are still constituent parts of a single integrated block with just one valve rack and one sorting system for closures. The Modulfill Dual features around 60 filling valves fewer than a one-filler solution would need for the same output. Thanks to its compact size, the filler takes up less space, but its output is still almost 20% higher. Smart process control system for the stretch blow moulder Steadily increasing production speeds present challenges: While the maximum output per blowing station was still at 1,600 containers per hour back in 2000, today’s stations can make up to 2,750 bottles per hour. So, a machine can turn out as many as 100,000 containers per hour. Of course, at such high speeds, even the slightest deviations from ideal conditions can quickly and significantly impact an entire production run. Two more important trends must also be borne in mind: First, consumers especially are calling for increased use of recycled PET material (rPET). But not all rPET is created equal. Any inconsistencies must be offset in the blow moulding process, to ensure that every container meets the specified quality criteria. The second trend is the continued effort among beverage producers to further reduce the weight of their bottles. PET (whether recycled or virgin material) is costly, and highquality rPET is a scarce commodity. And so it only makes sense to reduce the weight of the containers as much as possible – to save on materials in the production process and to further reduce the containers’ ecological footprint. The wet-end block achieves an output of 100,000bph 0.5 l water bottles.
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