Hypoxia Aseptic Filling of Steam-free Beverages in Three Steps

In order to reduce the oxygen content in the bottle mouth, especially when using flasks in PET aseptic filling process, Krones AG, Neutraubling, Germany developed a three-step filling program. Relying on this technology, the normal oxygen content of 21 percent in the air can be reduced to 10 percent first and then to 5 percent. After the three filling steps were completed, the oxygen content in the bottle mouth was only 2%.

Nitrogen injection in the capping machine

Krones has confirmed after a long period of time that the effect of reducing the oxygen content in the capping machine is significantly more effective than in the filling machine or in the transfer device between the filling machine and the capping machine. Therefore, assembling a set of nozzle system in the capper becomes the basic mode to solve the solution. The nozzle system blows nitrogen at the same time into the mouth of the well-filled bottle and the lid that is located just above the bottle opening. After such treatment measures, the oxygen content in the bottleneck can be reduced to 10%. And this is only the first step to deal with.

Ring enclosure designed specifically for nitrogen environments

The purpose of the second step is to reduce the remaining oxygen content to less than five percent. An annular cover inside the capper is the key to this step. The height of the cover must match the contour of the bottle and the mouth of the bottle. During the first step of the process, the nitrogen that was blown into the bottle mouth and the cap spilled out and formed a nitrogen atmosphere inside the outer shell. The capping process is completed in this environment.

Nitrogen bubbles replace air bubbles

The third step in the processing process is to reduce the remaining oxygen content to 2%, which is the most critical part. This step is of utmost importance, especially when processing beverages with foam. If the air bubbles formed during the filling process cannot be eliminated before capping, sufficient nitrogen cannot be injected into the mouth of the bottle so that the foam still contains a large amount of air. When the capping is over, the foam subsides and releases air and oxygen. To avoid this consequence, it is necessary to form nitrogen bubbles rather than air bubbles when filling.

2% residual oxygen content

It is the most effective measure to replace air with nitrogen before filling. This avoids the formation of bubbles containing air during the production process, which reduces the remaining oxygen content to 2%.

Twenty-one percent of the original oxygen in the bottle's air is first reduced to 10%, to 5%, and only 2% is left. Three steps take effect.

Source: Krones AG