Achieving Accurate Volumes - Gravity, Pump and Piston Filling Machines
Several different filling machines can be used to achieve accurate volumetric fill levels on a packaging line. The most common machines from Liquid Packaging Solutions include the gravity filling machine, the pump filling machine and the piston filler. While each of these liquid fillers provides and accurate fill by volume, each does so in a slightly different manner.
Gravity Filling Machine
Gravity fillers, as the name suggests, rely on the force of gravity to move liquids through the filling machine product pathway and into the waiting containers. Typically, product will be held in a tank over the fill heads. A simple timer will open and close the fill head valves to allow product to flow into the bottles. The LPS gravity filler allows for the fill time for each head to be set individually, ensuring each bottle on a multi-head machine will receive the proper amount of product. As gravity is the driving force for this filler, it will normally be used with lower viscosity, free-flowing products.
Pump Filling Machine
Pump fillers use pumps to push product through the pathway and into the waiting containers. Like the gravity filler, a simple timer may be used that allow the pumps to run for a specific amount of time, with each fill head having its own pump. However, pump fillers can also be run using a pulse based fill. Rather than time, the pulse based fill will use some function of the pump to hit specific volumes. For example, a packager using a gear pump may use each quarter turn of the gear as a pulse. If the fill is set for eight pulses, two full turns of the gear will push the correct volume of liquid into the bottles. As the pumps provide an extra push to the product, pump fillers can be used for thick as well as thin products.
Piston Filling Machine
The piston filler uses a piston to push product from a cylinder with each fill cycle. As the volume of the cylinder never changes, the product pushed out of the cylinder will be the same with each push. The stroke of the piston can be adjusted to allow for different fill volumes using a single piston size. Again, the piston supplies an extra push to the product, allowing the filling machine to handle both thick and thin products. The cylinder working as a pathway for product also means a more open route, which makes the piston filler ideal for products like sauces, jams and jellies that may include particulates.
Each of these popular volumetric fillers offers different benefits and the machine chosen for any product will depend on a number of different factors including the product itself, the size of the containers, necessary speed and more. To learn more about any of these filling machines, contact Liquid Packaging Solutions today.