As a practical, economical and lightweight packaging medium, polyethylene terephthalate (PET) is without peer and has become widely used by soft drinks producers. But as environmental pressures have grown, the industry has come under increasing pressure to reduce the amount of plastic it uses and increase recycling. Annette Farr assesses the progress that has been made.

Aware that the green credentials of all packaging formats are under scrutiny, reducing the amount of polyethylene terephthalate (PET) plastic used in the soft market has become a priority for both drinks producers and packaging manufacturers.

PET offers many advantages for both consumer and manufacturer. The PET bottle is safe and convenient, especially for drinking on the go. For the producer, PET is cost effective and flexible, while creative potential and advanced barrier properties make it suitable for today's healthy non-alcoholic drinks and bottled waters.

However, environmental concerns over waste plastic represent a big downside for users of PET. As PET has become ever more popular - according to Canadean's Wisdom database more than 8 in every 10 litres of bottled water sold is packed in PET - so the amount of plastic entering the waste stream has increased. This is not, however, a doomsday scenario as both bottle manufacturers and brands are being proactive in reducing the volume of PET used in soft drinks production and in recycling.

Overall, in the US, Napcor (National Association of PET Container Resources) says that since 1978 manufacturers have reduced the weight of a 2-litre soft drink bottle by about 29%, from 68g to 48g. And, latterly, a global competitive market has emerged amongst the plastic packaging fraternity to develop ever more lightweight bottles.

Last year Sidel, the French-based supplier of complete bottling-lines, launched what it claimed to be the lightest 500ml PET bottle yet for bottled water. Simply called NoBottle, it weighs 9.9g compared to the average 13g to 16g.

The technology used is called Flex. This combines plastic's flexibility with shape memory, eliminating the need for ribs, so designers are free to create all sorts of shapes, even for extremely lightweight bottles. The bottles are said to be easy to grip, supple, substantially less brittle than conventional bottles and better able to withstand conveying, packing, transport and handling.
 
"Bottled water consumption is expected to expand by 5.7% annually between now and 2010," says Franck Hancard, Sidel's packaging solutions manager. "The additional tons of waste eliminated by this new, lighter design will be considerable."

Flex technology was used in Nestlé Water North America's Eco-shape bottle project launched in 2006; this resulted in a 500ml bottle that was 30% lighter than the average bottle of this size. Poland Spring, Ozarka Natural Spring Water, Zephyrhills Brand Natural Spring Water and Pure Life brands have all converted to the 'Eco' bottle.

Meanwhile, the giant German beverage packaging manufacturer Krones announced earlier this year that it has set a new standard with its 500ml bottle which weighs 8.8g. The company says every tenth of a gram less per bottle results in considerable material and cost savings over the course of a year. Lightweighting was achieved by reducing the amount of plastic used in the mouthpiece from 3.5g to 1.959g, dispensing with the neck ring and by reducing the wall thickness.
 
Italian-based PET Engineering has halved the weight of its single-serve 100ml bottle from 10g to 5g. Called the monodose, the bottle is intended for dairy-based and functional drinks. It was developed in partnership with the Canadian company Husky Injection Moulding Systems, the American firm Invista and Sleever International.
 
The UK's Waste & Resources Action Programme (WRAP) believes that by switching to lightweight PET bottles, soft drink manufacturers can demonstrate their commitment to packaging reduction and gain considerable economic benefits. Approximately 510,000 tonnes of plastic bottles enter the UK waste stream every year.

The organisation contends that if all 500ml and 2-litre PET soft drink bottles sold in the UK switched to lightweight preforms, 3,400 tonnes of packaging material could be saved annually. Significant energy savings of 2,811m kWh could also be realised.

Recently, WRAP took part in a project with PET packaging manufacturer Esterform which proved the commercial feasibility of reducing the weight of a 2-litre bottle from 42g to 40g. The project also looked at reducing a 500ml Radnor Hills bottle from 25g to 20g. William Watkins, managing director of Radnor Hills, says it "demonstrated that lightweight bottles can perform as well as heavier weight bottles, while offering significant commercial and environmental benefits".

Brand owners are taking responsibility for reducing the amount of material used.
Last summer, Coca-Cola Enterprises in the UK announced that it will be switching to a new lightweight 500ml bottle (24g versus 26g) for Coca-Cola, Diet Coke, Coke Zero, Fanta, Sprite and Lilt. Now appearing on shelves across the US is Coca-Cola's new 20oz PET contour bottle which uses 5% less PET. This latest version has added texture and grip enhancements that make it easier to hold, and a shorter cap for easy opening and consumption whilst on the go.

Meanwhile, Danone's 'Green Plants Initiatives' project has included a lightweighting programme, reducing the amount of plastic used in its bottles. Over the last 15 years, Danone says it has achieved a 30% reduction in the weight of its PET bottles. The company is also introducing recycled PET into its bottles.

The use of recycled PET is a pointer to the future. Already in the UK, smoothie manufacturer innocent uses 100% recycled PET in its product range, and significantly The Coca-Cola Company (TCCC) has declared an ambitious target to recycle or reuse all of the PET bottles it produces in the US market.

To this end, TCCC and United Resource Recovery Cooperation are opening the world's largest plastic bottle-to-bottle recycling plant in Spartanburg, South Carolina, this year. The plant will produce approximately 45,000 tonnes of food-grade recycled PET each year.