The engineering and materials used to make PET bottles are continuing to move in one direction: toward sustainability.
For beverage companies, the reason is obvious. Consumers are becoming increasingly sensitive to wasteful packaging and its impact on the environment.

As a result, the latest PET offerings tout recycled content or even biodegradability. At the same time, many PET manufacturers are emphasizing newly enhanced barrier protection in an attempt to expand into lucrative new beverage categories where they have not played before, such as wine.

The International Bottled Water Association has been tracking the average amount of plastic used in .5 liter (16.9 ounce) PET bottles, using published data from the Beverage Marketing Corporation (BMC) to determine a light-weighting trend in the bottled water industry. In 2000, the average weight of a plastic water bottle was 18.9 grams and since then has declined consistently on an annual basis. In 2007 (the last year BMC has complete data) the average weight of a PET water bottle was 13.83 grams, which represents a plastic decrease of 26.7 percent. This lightweighting trend is steadily continuing as some bottled water brands introduce consumers to a 10 gram PET bottle.

PET manufacturers are targeting virtually every part of the bottle in an effort to make them lighter. A lot of work, for instance, has gone into reducing the bottle finish. “I think the biggest thing that’s going on in the PET industry right now is that it’s a race for lightweighting,” says Jeff DeLiberty, Amcor PET’s director of business development. “As you can see with Gatorade and Powerade products, some of the flagship brands that are in PET, particularly hot fill PET, the finish sizes have gone from 43 millimeters down to 38.”

Adds Tracy Momany, vice president, Product Development Group for Plastic Technologies, Inc.: “When you think about taking a finish that was 3.5 grams and making it less than 2 grams, there is a lot of technology that needs to go into making that happen.”

She continues, “In order to achieve these lightweights there’s been a lot of improvement in the strength of the package, engineering the packages to be stronger. And blow molding and filling systems have improved to handle these really lightweight bottles. Sidel, Krones and others continue to announce that they can handle lighter and lighter bottles.”

Boosting recycling rates of PET is another goal of many suppliers, who see it as a sure-fire way to make eco-sensitive consumers feel better about buying beverages in plastic packaging.

Veriplas Containers has come up with a logo for its customers touting that its bottles have been “made with recycled plastic.” Explains Speed Stodghill, director of sales for Veriplas, “We believe there is a demand for eco-friendly packaging. And one of the great things about PET is that it is recyclable.”

Some biodegradable PET bottles also have been appearing. ENSO Bottles has introduced the world’s first biodegradable plastic bottle. The company says its EcoPure technology is the only “truly” biodegradable PET bottle in anaerobic, aerobic and compostable environments.

Companies also have been working to improve the appearance of PET bottles. Explains Alex Fioravanti, VP, material sales, Constar, “With DiamondClear we use a new chemistry that does the oxygen scavenging and it’s crystal clear so you showcase the package and the product in the package much better than you could before. We’re also able to provide longer shelf life, or the same shelf life using less material.”

Companies like Constar also are striving to create a cleaner bottle look through innovations in the bottle’s structure. Constar’s vertical compensation technology absorbs vacuum through a combination of the base of the bottle moving and rib geometry within the label panel that is able to compress slightly to absorb the vacuum that’s created after hot filling. Explains Fioravanti, “When the consumer touches the bottle there’s much less geometry there, such that the tactile experience for the consumer is also very much improved because you don’t get that crinkly feel of the label.” In fact, The World Packaging Organization just recently awarded Constar International a 2009 WorldStar Award, the international packaging industry’s most prestigious honor, for a lightweight, sustainable 750 ml PET wine bottle for Boisset Family Estates’ 2008 Beaujolais Nouveau.

From Beverage World February 15, 2010