Capping Machines and Purging - Packaging Line Placement
While there is a common sense alignment for machinery on a packaging line, it is also true that most packaging systems can be set up in whatever order makes sense to the individual packager. Most lines will rinse, fill, cap and then label, along with other packaging tasks such as coding, induction sealing and more. When a packager uses a nitrogen purging - or other purging - system, however, there is a good reason to place the purging machine in a specific spot on the packaging line.
Nitrogen purge machines typically remove oxygen from the headspace of a filled bottle or other container. This is done to protect the product. Many products that interact with oxygen will also be broken down by oxygen. When talking about shelf life, the most common example may be food products. Food products exposed to oxygen, or taken out of their packaging, tend to spoil faster than food left in a container. However, even oxygen in the head space of that container can shorten the shelf life of the food product.
Nitrogen, on the other hand, is not only colorless and odorless, but does not react like oxygen to break down products. A nitrogen purge machine, then, works to replace oxygen in the headspace in order to extend the shelf life of a product while maintaining the taste, texture and color of the product at the same time. Of course, the more nitrogen retained in the headspace before the product is sealed, the more effective the purge. For this reason, the nitrogen purge system will almost always be placed right before the capping or sealing machine on a packaging line.
While it may seem like a better idea to purge the empty container before it even enters the packaging line, this would be a miscalculation. Though the bottle may be full of nitrogen, the introduction of the product would displace that nitrogen and much of the remaining nitrogen, if any, would dissipate and allow oxygen to re-enter the head space by the time the bottle or container reached the capping or sealing machine. So, when purging for extended shelf life (there do exist other reasons for purging with gas or liquid nitrogen), the capping machine and nitrogen purge machine should almost work as one task on the packaging line.
In most cases, the nitrogen purging equipment can be set up anywhere along a conveyor system. Placing the purging machinery right before the containers enter the capping machine allows for the retention of a maximum amount of nitrogen, which in turn makes the purging machinery that much more efficient! For more information on Nitrogen Purging, Capping Machines or any of the other packaging equipment manufactured by Liquid Packaging Solutions, contact a Packaging Specialist at LPS today.