Liquid-nitrogen dosing systems are becoming a popular means of ensuring the stability and extending shelf life of non-carbonated products in plastics bottles and cans. And Coca-Cola should know: it’s just installed two of them. Michelle Baillie went to Belgium to find out more.

The world-wide shift from carbonated soft drinks towards still and lightly-carbonated juices and waters has focused fillers’ minds on finding ways of using lighter plastics containers without them collapsing during transit and handling.

For without internal pressure, PET bottles, especially in larger sizes and with thinner walls, are unstable. And will be increasingly so as resin prices rise and weights fall.

But a technique for pressurizing containers that has been in use in the canning industry for about 20 years is finding wider application in the bottled juice and water industry. And it uses the most commonly available gas: nitrogen.

A small volume of nitrogen in liquid form added during the filling process expands and provides just the rigidity needed to enable a PET bottle to withstand the rigours of palletizing and shipping.

It’s a process, however, that fillers have been overly cautious of adopting, suggests the leader in the technology Vacuum Barrier Corporation (VBC), because the very low temperatures necessary for the gas’s handling – almost minus 200 deg C – are regarded by many as awkward to manage.

But it’s a challenge that VBC’s European arm Vacuum Barrier Systems (VBS) finds customers are increasingly willing to overcome. Because the cost savings in lighter containers quickly make the process pay.

Belgium-based VBS originated as a supplier of liquid nitrogen transfer piping manufactured by Boston-based VBC, a cryogenic hardware manufacturer. It’s a technology still used and supplied to a variety of industries for applications that need intensive cooling. Guy Charbonnier and Gerd Büsing have managed the growth of Vacuum Barrier products in Europe since 1980. At the VBS base in Waterloo, Belgium, they were joined by Phillip Kerchx in 1998 to handle the growing liquid nitrogen dosing market.

The dosing technique developed by Vacuum Barrier is one especially devised for filling non-carbonated beverages. Problems with easily crushed and damaged packages of still products in vending machines brought to light the need for a technology that would enable them to be sold and offer an alternative to CSDs.

Another pay off is that the products have a longer shelf life – the nitrogen replaces the oxygen that would otherwise degrade sensitive products like fresh juices.

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Reprinted from The Filling Business © September 2005