'Roll-and-blow' for thin-walled polypropylene bottles

French equipment manufacturer Serac acquired Roll N Blow developer Agami in 2014. The technology was originally developed for manufacturing polystyrene (PS) containers.

“There is a market for PS where it is already used for pots in fresh dairy,”​ said Agami founder Stylianos Eleftheriou. “But since then, we’ve seen more interest in systems for polypropylene ​[PP].

Better strength ​

“It’s resistant to hot-filling, offers better strength and it is easier to add an oxygen barrier for longer shelf-life.”​

Unlike either extrusion blow-moulding or injection stretch blow-moulding, Roll N Blow works from preformed polymer sheet on a reel and, while the sheet is heated to be stretched and blown, it is never fully melted.

“It is much easier to optimise this system and create thin-wall bottles than with extrusion blow-moulding,” ​said Eleftheriou. He estimated that, depending on the application, the technology could work out at least 10% cheaper than extrusion blow-moulding.

“If you compare Danone’s Actimel, for example, it is high-volume and optimised over 20 years or so,”​ he said. “We could reach a similar ratio, but much more easily.”​

Options ​

Although two machines are installed in Russia and Morocco, and another two are on order for Belarus and Turkey, no customer is yet creating a barrier bottle. But options with an ethylene vinyl alcohol barrier are being promoted for products with sensitive contents, such as vitamins, or milk shakes, juices and sauces with a longer shelf-life.

Output from Roll N Blow is around 30 cycles a minute with PS and 25 a minute with PP, not dependent on bottle size (which is normally in the 100500ml range).