With PET comfortably outstripping glass as its preferred delivery mechanism and with the global market requirement likely to exceed 47 billion units by 2010 (a year on year growth rate of around 6%), streamlining the overall production process to achieve maximum cost and performance efficiency has become the water bottling sector’s key imperative - notably though seamless production configurations, and a more sustainable materials usage strategy.
In house blowing has long been the established norm outside of the North American market, with the adoption of more European manufacturing practices by the likes of Nestlé Waters and PepsiCo notwithstanding. The greater bulk of prefilled bottles still continue to be blown, palletised and shipped by a well established specialist rigid plastics converting sector.
An estimated 40% of the world’s bottling plants have been traditionally engineered and sourced on a perceived best in class basis from individual suppliers. But the emergence of new entrants into the industry aligned with the pressures imposed by margin sensitive time to market supply chain criteria, is likely to make them the exception rather than the rule.
“The proportion of water bottling lines that aren’t structured on a fully automated and integrated combination of blowing and filling equipment will be less than 20% of all installations worldwide in the next five years,” Sacmi Filling General Sales Manager Matteo Quaini told water innovation this month. Not surprising then, that most of the leading blow moulding systems and equipment manufacturers are now heavily promoting their own one stop shop combination or integrated process solutions stretching from preform to finished pack.
Sidel were first to choose a combined blowing and filling system ten years ago through the introduction of the Combi. Their production capability has now been extended into the 34xs (extra small) for blowing, filling and capping a run of single serve up to 0.7 litre format PET water bottles at a rate of 61,200 per hour.
“The market immediately saw the value proposition, which gave us a considerable competitive edge at the time,” says Combi & Water Fillers Product Manager Andrea Lupi. “In the interim period we’ve installed more than 200 Combis worldwide; of which over 60% of these are used specifically for bottled water and the rest for carbonated soft drinks (CSDs) or aseptic-fill products.”
The key advantage provided by a combination approach is the elimination of intermediate conveying or accumulation equipment to realise at least a 4% gain in overall efficiency, as well as facilitating format changeover. Without air conveying, the Combi is also ideally suited to lightweight bottle production, significantly lowering costs for purchasing raw materials and energy consumption.
Because of the neck handling and positive transfer of bottles between blow moulding and filling, the system is not bound by conventional design limitations. This expands the possibilities for bottle shapes and light weighting, in turn leading to lower material costs that can represent anywhere between 65-80% of the total cost of an empty package. Thinner preform walls combined with total process control also result in significant savings through lower blow moulding air pressure, and less energy used for thermal preform conditioning.
In addition to delivering a streamlined process, the capability to offer front to end service opens the door to meeting the overall production requirement throughout an entire new start up plant. Sidel’s Combi 20 Select GL machines provided the bedrock on which the French company installed twenty complete lines to facilitate existing customer Ting Hsin’s extension into the Chinese mineral water market last year. Full configuration incorporated Alfa Rollquatro F35 labellers and Gebo conveyors, with each line producing 36,000 PET 0.6 litre size bottles per hour.
With over 70 combination systems installed worldwide, Krones also has a new solution on the market: the Contiform S14 PET stretch blow moulding machine directly BLOC synchronised with a filler to which containers are conveyed via a transfer star wheel at a synchronised speed.
Further to the concomitant energy savings, risk of contamination and soiling is also eliminated. Outputting speed can be as high as 72000 blown and filled bottler per hour. Krones claims that demand for its range of combination systems is growing by 40% a year. The company has an impressive strike rate in fulfilling turnkey operations. It has recently completed a €100 million installation of four fully integrated PET filling lines at Altmühltaler Mineralbrunnen’s new greenfield site near Kassel, Germany, with a projected daily output of 4 million fills. Krones has undertaken responsibility for the still and carbonated water products (plus a soft drinks facility), supplied the entire process section including the filters and water softening system low pressure compressors and the heating plant. Each of the four PET bottling lines incorporates a Contiform S24 blow moulding machine capable of delivering 44,000 x 1.5 and 2.0 litre PETbottles per hour.
Moving into combination solutions from the other end of the production line, Italian manufacturer Sacmi Filling has now installed over 25 of its Solo Mas 14/60/15 Combo system, first introduced three years ago. Comprising a synchronised blower, filler and capping facility, the Combo can output 22400 x 1.5 litre PET bottles per hour, but can reach nearer to 36000 single serve 20 cavity mould units, says Matteo Quaini.
“Operating within an atropine environment, which is what the big water groups are now asking for, risk of contamination is negligible. As the Combo eliminates the need to rinse prefilling, overall utilisation of factory floor space is significantly reduced. These systems aren’t necessarily that much faster, but in all round terms are considerably more efficient by eliminating two stages in the overall process.”
Using sustainable materials
Filling line equipment suppliers are responding with considerable ingenuity to the main routes of greater sustainability such as returnable or reusable PET, glass and lighter weight manufacture.
KHS has worked closely with its German customer the RhönSprudel Group in developing and installing ultra clean plant technology to meet the production requirements of over one third of the €200 million turnover, generated through mineral water packaged in returnable PET bottles at a rate of 30,000 x 1.0 litre and 75cl size units per hour.
The KHS’ returnable PET line comprises a superblock, bottle washer and ultra clean process filling technology.
Once depalletised, refillable PET bottles are conveyed direct to the superblock which comprises sorting, decapping, delabelling, and the company’s patented Innocheck FS (foreign substance) inspection capabilities. In passing through this preliminary stage, all bottles containing unrecognized substances are automatically channelled out via a separate rejection segment for disposal.
‘Good bottles’ are conveyed to the Innoclean EE single end bottle washer and rinser prior to filling, via a volumetric computer controlled single chamber Innofill DRV120 filling station system. This phase includes aseptic membrane and sealing processes. Further sterilisation precedes final capping.
Investment required in processing returnable PET with an estimated 7% rejection rate prefilling, and the time spent in completing the loop - it can take anything up to four months for bottles to make their way back from the market - are significant disincentives to adopting a recyclable strategy. For blow moulding machinery manufacturers looking to extend their reach into the overall bottling process, the development of lighter weight packages represents a far more obvious and attractive proposition.
While both Sidel and Krones have recently been grabbing favourable headlines in their pursuit of the below 10g lightweight format, there are industry reservations about whether the single digit construction technology is a viable proposition.
Sacmi is blowing between 13–14g for 50cl flat water bottles, which Matteo Quaini feels is about as low as the market is realistically prepared to go. “In terms of raw material price, then yes of course, it’s an improvement. However, an interesting comment that we’ve had from two of our customers - both of them positioned at the top end of the bottling sector - is that they don’t agree that continuously lowering the weight necessarily improves overall efficiency and line performance.”
“Running such lightweight bottles on a line can be a problem. OK, if you’re a leading brand and can reduce the weight by say 1.5g then the saving can add up to several million euros. On the other hand, however, if you then lose ten points of efficiency on a complete line by slipping from say 95,000 bottles to 85,000 per hour then that can likewise result in a negative millions of euros. I believe that this trend is coming to an end now.”
Ensuring rigidity and strength
While the prefilling carbonation process effectively adds rigidity to a PET bottle by default, formats containing flat water can require liquid nitrogen dosing to supply the necessary degree of internal pressure to withstand handling and transit.
US based Vacuum Barrier Corporation (VBC) is the global market leader in supplying liquid nitrogen injectors with over 1,000 installations worldwide, of which well over 50% are specifically used in bottled water sector.
Pressurisation is used for PET bottles, thin wall cans and a variety of other package types. This controlled, pure liquid nitrogen dosing, provides package strength to eliminate panelling and palletising problems; it also provides vending machine capabilities, facilitates cost savings with the use of lighter weight plastic and a greater customer appeal with a firmer package.
Another added benefit of liquid nitrogen injection is inerting to displace oxygen from the headspace.
VBC’s Nitrodose systems provide a precisely timed drop of liquid nitrogen into the headspace of the package. The cold liquid nitrogen turns to nitrogen gas at room temperature and expands rapidly. The bottle being capped at a certain time after dosing creates a defined internal pressure to the package.
Rate of dosing can be as fast as 1,200 PET bottles per minute (28mm finish) with VBC’s high speed system operating in discreet mode. An inbuilt dosing capability ensures that it cuts on and off between bottles to ensure no wastage and provide a cost effective solution in terms of consumables usage.
“Without the appropriate internal pressure it wouldn’t be possible to go with lightweight bottles for non-carbonated water,” explained North American Sales Director Mike Johnson.
“We’re able to inject precisely as much liquid nitrogen as the customer and the bottle requires. That could be anything from just enough to get those PET bottles safely through a labeller, to ensuring sufficient pack rigidity for the bottles to be inventoried up to three or four pallets high. An average dose is around 0.1g, and the average pressure around 25psi. The dose would be unlikely to exceed 0.3g for bottled still water. The reason it doesn’t change that much across the different pack formats is that we’re only pressurising the headspace above the water content. The volume between content and cap tends to be pretty much consistent regardless of unit size. Bottles not going this route will tend to have a heavier wall construction. Otherwise, it could be that there’s either no real requirement for palletisation or else they’re already using secondary board packaging for external protection in warehousing and transit. In the US, for example, a 36oz case of water could be delivered into the retail outlet supported by a corrugated base and shrink wrap.”
Not all blow moulding manufacturers agree that the introduction of liquid nitrogen is essential to improve pack rigidity. According to Sidel’s Andrea Lupi: “It’s the evaporation of the liquid nitrogen just before closure, that provides the necessary pressurisation to enhance bottle strength; however, it’s not necessary as long as the bottle is strong enough to support the top load. With our ‘No Bottle’ technology we’re trying to work without nitrogen; it’s viable because of the shape of the bottle itself. “
New developments to the dosing system have been introduced with combination blowing filling systems in mind, says Johnson.
All the bottlers have CIP (clean in place). At the end of a run and before they get going on the next one, they go through an aggressive wash down process - sometimes using a caustic solution. If any moisture gets inside the old style dosing head, then everything would freeze up because water is the enemy of liquid nitrogen. In the past, a cover would snap over the dosing head to prevent any moisture getting in. But with these high speed automatic filling lines, bottlers were reluctant to have to remember to put that cover on and take it off as required.
“We’ve now introduced a automatic CIP protection device (available as an option on all VBC dosing systems), which ensures that whenever dosing isn’t in progress the valve automatically shuts off. It’s not airtight, but just sufficient to withstand any moisture.”