2020 Product Review: Nitrogen Purge Systems

Of the thousands of different liquid products placed on the shelf every year, a good number are foods, beverages, medicines or other items made for human consumption. Many of these items have a negative reaction to the oxygen that is trapped in the headspace of the bottle, causing products to break down over time, which leads to what everyone knows as expiration dates.

While nitrogen purge systems will not completely eliminate expiration dates on all products, these machines can work to extend the shelf life of the product by eliminating some of the oxygen that gets trapped between the product and the top of the cap. Using nitrogen to replace the oxygen also helps the products maintain their taste and color.

In most cases, the nitrogen purge system will be placed on the conveyor system between the filling machine and the capping machine, with the purge taking place right before the bottles or containers are sealed. This set up reduces the amount of oxygen that re-enters the headspace of a container before being sealed. Purging and then waiting to close the containers or purging to far prior to the capping process can reduce or eliminate the benefits of the machinery.

In some cases, a nitrogen injector may be seen at other points on a packaging system. Nitrogen gas will almost always be used to remove oxygen from head space and extend the shelf life of products. However, liquid nitrogen systems may be used at the beginning of a packaging line to strengthen brittle plastic bottles. These two systems really serve two different purposes, as nitrogen used to strengthen bottles will most likely dissipate before containers are filled and then sealed by the capping machine.

While most purge systems will simply attach to the conveyor system of an automatic line. A typical system will provide a burst of nitrogen as the container passes by on the power conveyor system, moving immediately into the capping area. However, custom systems have been designed by Liquid Packaging Solutions for special projects, including stand-alone purge and cap machinery. To learn more, visit the LPS Nitrogen Purge page or contact a Packaging Specialist at LPS today.