PETpla.net Insider 06 / 2012

BOTTLING / FILLING 33 PET planet insider Vol. 13 No. 06/12 www.petpla.net sensitive BEVERAGES Fine-tuned 18,000bph line The Contiform H 12 is equipped with the Relax-Cooling (RC) process, a feature indispensable for the PET bottles’ base stability while being hotfilled. Both the mould base and the mould carrier are water-cooled, thus ensuring fast mould cool-down. The combination of the RC process with a lower mould temperature than that obtaining in a traditional heatset process permits the use of aluminium moulds, which significantly cuts the costs involved. After the stretch blow- moulding process, the bottles’ bases are water-cooled for fast stabilisa- tion, with the bottles then passed to the Volumetic VODM-PET filler, where they are hot-filled at a product temperature of 82 to 84°C. A function for pressurising the bottles with liquid nitrogen has been directly integrated. This will evaporate immediately after the bottles have been closed, build- ing up a pressure of 1.5 to 2bar in the head space, thus compensat- ing for the PET bottles’ susceptibility to shrinkage during cool-down. This entails a slight drop in the fill level. After the yellow 38mm flatcap has been applied, the bottle’s head space is sterilised in a bottle inverter over a defined transport section. The downstream LinaCool cool- ing unit causes the temperature of the product in the bottles to drop from 87°C to around 35°C. This cool- down leads to a reduction of product volume, thus creating an underpres- sure in the bottles’ head space. The nitrogen added during filling prevents the bottle from contracting, ensuring the requisite bottle stability. Down- stream of the cooling unit, further bottle handling takes place at ambient temperature and a residual pressure of 0.3 – 0.5bar in the container. The bottles are labelled with wrap-around labels with a Krones Contiroll. Process technology Krones also supplied the pro- cess-engineering kit required. The VarioFlash H flash pasteuriser, with a product tank, a shell-and-tube heat exchanger and a product de- aerator, assures the correct quality and temperature of the juices. Here, the oxygen is easily removed from the juices, so as to prevent oxidation during heat-up and the heat-holding phase. One feature worth mention- ing is the high spread in terms of the shell-and-tube heat exchanger’s output, ranging between 19,800l and 4,800l – in other words, precisely what the company needs for running a flex- ible production operation that handles both large and small containers and an ultra-wide beverage range, not least for relatively small batches. The product tank, holding 10,000l, decouples the product feed and the heat exchanger while also serving as a rework tank. During product change- overs the tank serves as a batch tank for the product that has been expelled with water. “A filling dura- tion of three to four hours for our facility means a proper- sized batch”, explains André van Schuijlenburg. “And this was where the actual challenges for Krones were hidden, because, you see, we didn’t want to lose too much juice during product change- overs. When compared to beer, which consists of 95% water, juice is a very expensive product. This criti- cal point received maximised atten- tion during commis- sioning, with the result that today our product loss comes to around 1.5%, which is very good indeed. And this covers all the equipment involved, from prod- uct treatment and filler, right through to labelling and packing.” In fact, the huge output achieved, and the disparate parameters involved, such as a different propensity to foam during filling, for example, had to be given due attention during each step in the production and filling operations. What deserves a specific mention here is the interrelationship between the cooling unit and the flash pasteuriser: the warm water from the tunnel cooling unit, at approx. 55°C, is used for the first pre-warming stage in the Vario- Flash H. www.krones.com The Contiform H 12 is equipped with the Relax-Cooling process, a feature for the PET bottles’ base stability while being hotfilled. Down the stream: The Modulpal palletiser.