Aventics PET bottle tech adjusts pre-blow molding in real time

Aventics is responding to a trend towards more complex PET (Polyethylene terephthalate) bottle shapes and smaller batches with a PET bottle formation that can be controlled and adjusted during the blow molding process.

The company believes it is entering uncharted technological territory with the patent-pending technology which it will debut for the first time at drinktec 2017 in Munich, Germany (September 11-15).

Pilot phase

It claims to have partnered with ‘a major filling company’ to complete extensive research on the blow molding process and has ‘validated numerous sample settings’ during the pilot production phase of new bottles.

PET bottles rank among the most successful consumer packaging formats, as the second most-sold pack format to the global consumer goods marketplace, and a pack format that continues to record well-above-average packaging growth, according to Euromonitor International.

They can be cylindrical or shaped but all have a narrow neck for pouring. They are common in soft drinks, mineral water and edible oil and used in non-food categories.  PET jars differ from PET bottles as the mouth of the container is wider to enable consumers to “dip into” the jar.

Ranked number one and the clear pack of choice for the soft drinks industry, the PET bottle globally accounted for 57% of all soft drinks sold in 2015, its penetration and growth being positively impacted by its dominant presence in the strongly performing bottled water category,” said Rosemarie Downey, head, global packaging research, Euromonitor International.

She added, the importance of “rightsizing” is evident in soft drinks in the shift towards single-serve soft drinks and smaller variants over larger standard pack sizes, noted in categories like carbonates, where obstacles to growth lie on health grounds.

Reducing the pack size has proven valuable to enable consumers to better measure and regulate their soft drink and calorie intake,” said Downey.

Coca-Cola Canada

For instance, in 2015, Coca-Cola introduced in Canada a 500ml PET bottle to replace its 591ml size for its flagship Coca-Cola brand and the 310ml slimline beverage can in place of the former 355ml size, while, at the same time, reducing the sweetness of the syrup formulation, reducing portion size, calorie and sugar intake even more.

Reduction in pack size is not exclusive to single-serve sizes, there is also evidence of family packs shrinking in size with a shift from 2-litre to 1.5-litre bottles and both 1-litre and 1.25-litre bottles doing better to suit smaller households in Europe seeking to regulate a bit more how much of their favorite carbonated soft drink they consume.

In Switzerland, Rivella’s launch of its non-cola carbonate Rivella Cliq in a 1-litre PET bottle is just one more example of downsizing from the past year.

By combining a proportional valve, control electronics, and software, the Aventics technology records the actual values occurring during the pre-blow molding process and compares them with the set points.

The set points can either be stored in the electronics or transmitted via all common realtime Ethernet protocols and fieldbuses.

During a blowing period of around 200 milliseconds, enough control cycles are available to precisely control bottle formation. This allows process technicians to intervene as needed, for example to reduce material consumption and fine-tune the formation of the bottle wall,” a spokesman for Aventics said.

Additional energy savings are possible by lowering the pressure level or reducing the furnace temperature.”

Condition monitoring notifies maintenance early on to carry out the necessary work in planned maintenance breaks.

As a software-based technology, the bottle formation process can be changed easily, without any mechanical alterations, and specific to each blowing station on the machine.

The software can also automatically control process events, for example reaching the yield point and target bottle volume, according to specifications and keep them constant provided no wear limits have been reached.