The Big Four – Gravity Filler, Overflow Filler, Pump Filler and Piston Filler

Following a holiday weekend that also included some great final four matchups in both men's and women's basketball action, we starting thinking about what a filling machine matchup might look like on the production floor of NPACK. Of all the possible bottle fillers that could be manufactured at NPACK, there are undoubtedly four designs that stand out from the rest, our own Final Four, if you will. We take a brief look at each below, keeping in mind that other principles and custom designs are always available for special projects!


The first of the big four bottle fillers is the gravity filler, which uses a popular volumetric filling principle. Using an overhead tank, gravity filler nozzles can be set to open and close for specific amounts of time, allowing each fill head to be accurately set to dispense the right volume in to each bottle. As gravity is used to complete these fills, thin, free-flowing products work more efficiently on these machines versus thicker, slower moving liquids. As with all of the filling machines on this list, the gravity filler can be manufactured as both a semi-automatic machine or as an automatic bottle filler. Semi-automatic tabletop models can be ideal for start-up companies or companies with limited space to package.


The overflow filler provides an alternative to the gravity fillers volumetric fill. Rather than placing a specific amount of liquid in to each container, the overflow filling machine fills each bottle to an identical level. This provides an ideal solution for packagers using clear containers when it comes to shelf appearance and aesthetic value. Even where a packager has a specific tolerance that must be met for volume, the overflow filling machine is almost always an option, but will depend on the manufacturer of the bottles to a certain extent. Due to the fact that product not only enters the bottles through the nozzles, but also overflows back through a different port in the nozzles, thin products also work best on the overflow filler. This machine also works very well to control products that tend to foam during the filling process.


So far, we have covered two liquid fillers that work well with thin, or low viscosity, products. The first of the two machines that work well with thick product is the pump filler. These machines have the advantage of matching a pump to the product being filled, meaning more efficiency and consistency in the fills, given all of the different pump types from which to choose. Pump fillers allow for both time and pulse based fills, with the pumps adding that little extra push to get thicker products like gels, oils and more. Though ideal for thicker liquids, some projects may also use pump fillers for lower viscosities as well.


Finally, the piston filler also provides a highly accurate volumetric fill, ideal for thicker, high viscosity products, but able to handle thinner liquids as well. The piston retracts from the cylinder of this bottle filler allowing product to enter. The fact that the volume of the cylinder never changes helps aid in the accurate volumetric fill. These filling machines are also great for thicker sauces, jams, jellies and other products that may contain chunks of fruits or vegetables or other large particulates.

Again, other filling principles do exist for different types of projects, but these big four filling machines probably make up well over ninety percent of the liquid fillers built by NPACK each year. To learn more about any of the packaging equipment manufactured in the La Porte, Indiana plant, browse the NPACK website or give us a call to talk about your own unique needs.