For any packager of a product, ensuring that the correct amount of liquid makes it to each bottle is an important task. Lining shelves with overfilled product can cost a company money, while underfilling containers can leave consumers feeling cheated! When a product foams, a packager needs to be careful not to fill bottles with foam that will eventually settle or disappear and leave the container with less liquid than desired. When using different filling machines, certain techniques or tools can be used to ensure the foam does not interfere with the fill.
One machine in particular, the overflow liquid filler, can help to fight foamy products simply by the way it is built to fill! Overflow filling machines use a special nozzle to fill each bottle to the same level, even where there is some variance in interior volume. The nozzles descend and seals cover the bottle opening. Once liquid reaches the correct level, it enters a return port and "overflows" back to the tank of the machine. When product foams, adding just a little bit of time to the fill allows liquid to force the foam out of the bottle, in essence controlling the foaming and protecting against underfills.
Overflow fillers work best with products that flow freely, which of course does not include every product on the market. Also, not all packagers want to fill to a level. If filling by volume or with some other principle, anti-foam nozzles can be used to control the foaming as it enters the bottles. Also, different from the overflow fill nozzle, a bottom up fill will not create a seal over the container opening, but instead will dive in to the container and slowly rise during the fill to minimize agitation as the liquid enters the containers.
Depending on the type of filling machine and the product or products to be filled, other options are also available to control foamy products without sacrificing efficiency or consistency. These techniques can be used on both automatic filling equipment as well as semi-automatic machines. If you are having problems with a product that foams or achieving accurate fills, contact the Packaging Specialist at NPACK for assistance in finding the right fix for your project!