Blow-moulding process makes lighter PET bottles

A new blow-moulding technology allows beverage makers to downgauge their PET (polyethylene terephthalate) bottles, thus saving on packaging costs.

Graham Packaging said it has speeded up the introduction of the technology due to the recent hike in resin prices due to the rising cost of oil. Personal care companies have generally been downgauging their packaging, whether made from plastic or metal, as new technologies allow them to make savings on the cost of materials.

The special process results in a lighter weight PET bottle without having to change design or sacrifice any performance characteristics, said Toshi Kojitani, director of Graham Packaging's unit for the product.

"This special moulding process in effect distributes the plastic where it's needed and removes it where it's not needed," said Kojitani. "The bottom line is that we're achieving overall light-weighting without any loss of physical function."

Graham Packaging started the development of the new technology two years ago and hastened the effort with the rise in resin prices that occurred last year, Kojitani said.

The first actual product to emerge from development will be a multi-serve hot-fill bottle. Kojitani said the bottle will be blown in the same mold used for the current, heavier version of the same size bottle. This technology will eventually be rolled out to the company's entire family of PET hot-fill bottles.

"The new bottle has exactly the same look, height, diameter, and footprint as the current version," he said. "Our tests and a trial run on a customer's filling line demonstrate that there's no difference in performance from the current container."

Ashok Sudan, Graham Packaging's executive vice president said the technology was developed to allow customers to make the switch without disturbing their brand image or filling line set-up. He noted that the evolution of PET bottles has consistently gone in the direction of lighter weight.

Graham Packaging has 87 plants in North America, Europe, and South America with net sales for the last 12 months of $2.4 billion.

The company is a leading US and global supplier of plastic containers for a variety of personal care items to companies such as Johnson & Johnson, P&G and Colgate & Palmolive and Unilever.

Last week Tetra Pak started the worldwide rollout of a stronger but thinner polymer packaging for liquid products, promising a host of companies within the food and beverage industry that the move will help them to cut costs and meet recycling standards.