Will an Overflow Filler Reach Accurate Fill Volumes?
Overflow filling machines are unique in that they allow bottles to be filled to a specific level in each container. This differs from other filling machines, such as gravity, pump and piston fillers, which fill each container with a specific volume of liquid. This does not, however, mean that an overflow filler cannot provide accurate volumes. The machine itself, however, will not be used to achieve accurate volumes.
Overflow fillers use unique filling nozzles that dive into a bottle and create a seal over the bottle opening. By using specific spacers on each nozzle, liquid is released into a bottle until it reaches a specific fill level. Once that level is reached, excess liquid "overflows" out of the bottle, typically back into a holding tank. In this way, the focus of the overflow filler is to reach a certain level in each bottle, regardless of whether or not the volumes are the same in each bottle or container. Using spacers, the filling machine allows the operator to adjust the level of the fill in the bottle.
This type of fill is ideal for packagers that are preparing products in clear glass or otherwise transparent containers. When the product can be seen in the bottle, a level fill helps to provide a pleasant, eye-catching presence on the shelf. The visible, level fill also ensures consumers do not feel cheated if a volumetric fill were to leave some containers with lower liquid levels than others. But what about products that need to meet volume requirements and also package products in clear containers? Do those packagers need to sacrifice accuracy or an aesthetic benefit when preparing their product for the shelf?
Overflow filling machines can provide an accurate volumetric fill, but only where the manufacture of the bottles is consistent and reliable. Given the technology and methods used today, many bottle manufacturers can produce bottles with interior volumes that are nearly identical. Using a bottle that can be formed consistently with an overflow filling machine can produce both level fills and accurate volume, though a packager will want to test bottles to ensure the interior volume remains enough unchanged to meet tolerances when required.
So while the overflow filling machine is not manufactured to reach accurate volumes within bottles, instead aiming for an accurate fill level, the machine can still provide an accurate volume range where a packager works with their bottle manufacturer to provide a container with consistent interior volumes. In other words, where other filling machines allow adjustments to the packaging machinery to reach desired volumes on each fill, the overflow filler will require a packager to work with the provider of the bottles to ensure the desired volume range can be reached while the machinery itself supplies the accurate level.
For those needing assistance in choosing the correct filling machine for a specific project, or for answers to questions about any of the filling machinery manufactured by Liquid Packaging Solutions, contact a Packaging Machinery Professional at LPS today.