PETpla.net Insider 07+08 / 2016

BOTTLING / FILLING 14 PET planet insider Vol. 17 No. 07+08/16 www.petpla.net A single system for blowing and filling bottles for CSDs and hotfill products Flexible filling Around the world, many PET bottling companies are handling both carbonated soft drinks and hotfill drinks such as fruit juices, isotonic sports drinks and teas. To do this, they gener- ally choose lines that are configured for one type of product or the other. But they don’t have to. Italian company Sipa has for some time been offering filling lines that can handle both types of product, with change-over times of just a very few hours. The third-generation SFR Evo3 rotary stretch-blow moulding machine and the Flextronic C multi-product volumetric filling monobloc are designed to offer more added-value than ever. According to Sipa, the abil- ity to blow and fill diverse types of container on a single line has been made without compromising any per- formance characteristics of the line. The latest generation unit is said to be fast, flexible and cost-efficient and to be easier to convert from production of hotfill to coldfill containers than its predecessors. The Flextronic C is suit- able for filling CSDs, still and sparkling mineral waters, cold- and hotfill juices. The principal differences between the lines for producing and filling the products lie in the bottle blowing unit, in the filling station and in the unit that prepares the product prior to filling. Blowing equipment There are important differences in the designs of CSD and hotfill (HF) drinks bottles - and hence also in the way they are produced. HF bottles are heavier than CSD bottles, since the vast majority incorporate spe- cial panels to stop them distorting as internal pressures change when the product cools down. They also tend to use wider necks: 38mm rather than 28mm. The two bottle types also differ in the base, with CSD variants gener- ally having a petaloid base that better resists the pressure from the carbon dioxide in the drink. The blow moulds on HF lines need to be heated so that bottles can be heat-set to increase the crystallinity of the PET and thermal stability; and also reduce internal stresses and the tendency to distort. For more than ten years now, Sipa has pioneered electri- cal resistance heating, which makes it easier to pass from one configuration to another and which is also more energy- efficient, easier to customise to differ- ent bottle shapes, more precise and responsive and safer to use, according to the company. The electrical heating circuit is incorporated into the mould shell holder; cooling water runs through circuits within the cavity walls. It is said to be easy to change moulds on the SFR Evo3 from CSD to HF and vice-versa. With new striker plates that allow rotation of the shell inside the shell holders, and with a “no tool” quick-change system for the mould base, the time needed to change each mould is little more than one minute. Furthermore, the system for chang- ing neck size is claimed to be faster than rival systems, with “no tool” quick change spindles a standard feature. It takes only two minutes to change the neck section on each mould. “Green” ovens on the unit are big energy savers. Compared to ear- lier generations of oven, they could reduce electrical consumption by up to 40% while keeping process condi- tions stable, thanks to the use of new lamps and special materials and coat- ings for the reflectors. Also available are electrically driven stretching rods, which brings more versatility in fine-tuning the pro- cess compared to pneumatic drives, “green” ovens which are energy savers and Sipa ARS+ air recovery system. Filling equipment CSD filling lines require contact filling and a CO 2 circuit to pressurise the empty bottle, so that isobaric filling can be carried out. HF systems, on the other hand, work with gravity fill and there is no need to control the pres- sure in the bottle during filling, which takes place at atmospheric pressure. What they do require, however, is tight control over the filling tempera- ture: recirculation through the filling valve is needed to reach and maintain the correct temperature prior to filling and during line stops, by means of a separate recirculation circuit. All valve components are designed to withstand temperatures of up to 100 °C. With the Flextronic C filling valve, the company believes it has achieved the task of combining all the require- ments for CSD and HF drinks filling into a single, compact design. This provides the user with a considerable extra level of flexibility in their filling operations. A further advantage of the fill- ing valve is its ability to handle pulpy products, not only in single stream con- figurations but also in double stream, for higher fibre and pulp contents that require the use of piston fillers. FILLING SPECIAL