The race for the lightest weight PET bottles reignited mid-2013. With bottle recycling in the spotlight in Australia right now, PKN takes a good hard look at the development of lightweight PET, from accessory feature to imperative.
When the first rush of lightweight PET bottles, such as Bottle Fly, NitroPouch and NoBottle, began to gain real traction in 2009, French firm Sidel and Italian company PET Engineering were the names most mentioned…
l-r: Bottle Fly, NitroPouch and NoBottle
…And lightweighting was not considered an imperative. "Some 'glamour brands' give priority to the elegance of the container, but these brands represent the minority of the market," admitted PET Engineering president, Moreno Barel, at the time.
In fact, the lightweighting of water bottles had begun in the mid '90s, at the same time that brand owners started selling water in PET.
Then, best in class 1.5 litre water bottles weighed about 40g and 500ml water bottles weighed about 22g. By 2006, the lightest 1.5 litre water bottles weighed 30g, and 500ml bottles 12.5g.
Sidel’s NoBottle launched in 2007 at 9.9g per 500ml bottle thanks to a technology known as Flex. After making its debut at the 2007 K trade fair, Krones launched its 8.8g 500ml still water bottle in 2008, weighing 6.6g. PET Engineering unveiled its Bottle Fly a year later at the Brau Beviale exhibition. It too was a 6.6g 500ml bottle.
Manufacturers - with the exception of Nestle - did not rush to adopt them. Both technology and corporate attitudes to the environment had some growing up to do.
Nextek managing director, Edward Kosior, stated what was the prevailing opinion at the time, "There are bottles of 10g or 11g which are commercially viable. They're quite delicate to hold, so there could be overspill if a consumer grips them tightly. However, when you get down to 6g, you're talking about a completely different concept. How to handle them for example? You can't hold onto the body and open them with a conventional closure. You'll squeeze them too much.
"When you get to that level, there's a whole range of other competitive technologies as well, because once you move away from the concept of a rigid package that's resealable and puncture-resistant and can stand unsupported, you're moving to a bag concept. Consumer thoughts about that may well shift and the market may not be there, though it's technically feasible."
Nestlé was then selling its water in Nigeria in 500ml Plocs (Plastic Low-cost Ovoid Containers) weighing 4.5g.
Even when carbon footprints and environmental responsibility began to be woven into the industry’s ethos around 2009, increasing the percentage of recycled content was the strategy most taken. Kosier suggested, "The use of recycled content is the fastest way of reducing the carbon footprint of any bottle. You can reduce weight, but you'll only achieve a carbon footprint reduction in proportion to that weight reduction, whereas if you incorporate recycled PET (rPET) into your bottles, you'll get a far greater reduction with no change in the actual container structure.”
Ultralightweights were not captured in recycling plants then, and were plagued by manufacturing issues such as clarity, yellowness, black specs, and an increased frequency of blowouts during blow-moulding.
The landscape changed in the middle of 2013.
Amcor Rigid Plastics created the lightest 1.9 litre hot-fill PET container of its kind, weighing just 59 grams. The company had developed Powerblock 3.0 technology to make the bottle, which comes with a 38mm finish, 13.2% lighter than the typical 68g bottle.
It overcame most of the industry’s reasons to resist. "The Powerblock 3.0 container is a major breakthrough because we achieved a highly sustainable packaging solution without compromising performance," Michael Lane, Amcor engineer, stated. "Our unique lightweight design retained line/stack handling performance and maintained ergonomic features for consumer handling." Its other advantages included optimised footprint (width and depth) for improved pallet pattern and corrugate savings.
Then, Evolight, the “lightest ever still water PET bottle” made its debut at Drinktec in November 2013.
Evolight by P.E.T. Engineering
This 500 ml PET bottle for still water, weighed in at 7.5 g, 31.5% less than its rivals, and it was able to withstand nitrogen filling. The EvoLight bottle was developed by P.E.T. Engineering of San Vendemiano, Italy, with support from Husky Injection Molding Systems, Bolton, Ontario, and used Husky’s new 26/22 neck finish with a weight of 1.91 g, plus P.E.T. Engineering’s own Swerve Neck and Sunbase designs. It also used X_Treme PET resin from Novapet of Zaragoza, Spain, to achieve the right balance of lightweighting and visual appearance.
The 1.5 litre version weighed 18.9g for still water and 22.5g for sparkling.
Also at the end of 2013 came KHS’ 500ml lightweight bottle with screw cap – the world’s lightest, according to KHS.
KHS lightweight PET with screw cap
This bottle weighs 10.9 grams. It was the result of a customer brief to develop a lighter weight bottle that was resealable. One of the key steps in the process was the reworking and streamlining of the bottle thread. And KHS managed to increase the stability of the recessed grip by modifying the bottle shape.
In January 2014, Sidel’s RightWeight 500ml PET bottle made its appearance. It weighs 7.95g, but had added strength into the equation by overcoming over-squeeze issue, making it easier for consumers to unscrew the cap, open the bottle and use without spilling the contents.
In May 2014, Graham Packaging Company introduced Escape, the lightest weight bottle in the smooth-walled, hot-fill category.
After the bottle is filled and capped, it goes through a Continuous Motion Activator (CMA), which inverts the base. This takes up the vacuum in the bottle and creates a slight overpressure.
The earlier inverse-base process required a complex bottle-handling system during manufacturing. The CMA eliminated that and it now fitted into the filling line. It was inexpensive, easy to install, and didn’t require an operator.
Mark Leiden, Graham Packaging's vice president of global marketing and PET business manager stated, "It's the equivalent of putting a labelling machine in a bottling line."
In June 2014, Sidel introduced its StarLite base for carbonated soft drink bottles, achieving the lighter weight and better performance it had introduced into still drink bottling a few months before.
Sidel StarLite
StarLite increases resistance while it lowers package weight and energy consumption of PET bottles, and maintains product safety due to its special shape, which significantly increases base resistance and stability. This means it can improve bottle rigidity, without compromising either lower package weight and reduced energy consumption during production or the safety standards of the beverage inside. The end result is a PET bottle that can cost less to produce, yet offers better pallet stability and higher bottle integrity throughout the supply chain.
The story of PET's last decade is a miniature version of the story of the world. Things have changed. Attitudes most of all.
