How Can I Achieve an Accurate Volumetric Fill?

When packaging liquids, getting the same volume into each container can be important to meet industry standards or regulations, to protect against product loss, or even to keep customers happy. So how do packagers ensure that they are accurately filling bottles by volume? Depending on the liquids being filled, the speed required, and other factors, several different filling machines exist to ensure such accuracy during the filling process.

Gravity Filling Machines

For free-flowing products, gravity filling machines offer a simple and economical solution for achieving correct volumes. Placing a tank over the fill nozzles, product is allowed to flow through the pathway and into the bottles via gravity, with nozzles opening for a pre-set amount of time. On LPS gravity filling machines, the time setting for each fill head can be adjusted individually to ensure accurate volume for each bottle, even when sixteen bottles are filled each cycle. As gravity is the only force moving the product, these machines are limited to low viscosity, free-flowing liquids to keep the filling process efficient.

Pump Filling Machines

For thicker products that may need a little more than gravity to flow efficiently, pump filling machines also allow packagers to achieve an accurate fill by volume. Each fill head will include a dedicated pump matched to the product and project to help move liquids from a bulk source, through a holding tank and into the containers. These machines can base the fill on time, just like the gravity fillers, or they can use a pulse based procedure. Pulse based filling will use the movement of the pump rather than time to complete the fill. For example, a gear pump will collect product between its cogs, or gears. During a pulse based fill, each turn (or fractional turn) of the gear will count as a single pulse, allowing a specific amount of product to be moved into containers with each cycle.

Piston Filling Machines

The piston filler provides accuracy during a fill by pushing product out of a never changing cylinder. As the piston moves into the cylinder, product is forced out through the nozzle and into the waiting container. As the volume of the cylinder never changes, piston fillers offer a solution for packagers preparing both thick and thin products. In addition, the large open area of the cylinder allows packagers of products with particulates, such as sauces and jams, to push through not just liquids, but the chunks of vegetables, fruits, or other large pieces.

Each of these liquid filling machines offer advantages when filling by volume depending on the product viscosity, containers, desired speed, and other factors of the specific project. Contact a Filler Specialist at Liquid Packaging Solutions for more information on any of the machines or for help finding the best volumetric filler for your own products.