How Viscosity Affects Volumetric Bottle Filling Machines

From tabletop to fully automatic bottle fillers, Liquid Packaging Solutions manufactures filling machines to best match the product at hand. While a variety of factors are taken into account to find the best solution, product viscosity is one factor that will always play a part.

The viscosity of products run on filling machines range from simple, free-flowing liquids such as water and other beverages to high viscosity, thicker products such as peanut butter, honey or window putty. Lower viscosity products can be filled using nothing more than gravity, letting the product flow from a high tank and opening and closing valves to achieve the desired volume.

Of course, performing the same task with a product like honey will not result in the most time-efficient of filling processes. A tank of honey placed above containers would take much too long to simply flow into those containers. In the cases where gravity will not get the job done, thick products are offered a little assistance through the use of a pump or piston. Both pump and piston fillers can provide accurate volumetric fills while using either the pump or the piston to give product a little extra push.

When using a pump to fill product to a specific volume, the fill process may rely on either time or pulses to complete the task at hand. While time based fills will simply allow the pump to run - and fill valves to open - for a specific amount of time, pulse fills achieve an accurate volume by measuring some movement of the pump. For example, when using a gear pump, each pulse may be a quarter turn of the gear. Different factors such as the actual product, speed, particles in the product and more will help determine the best method any given project.

Piston filling machines achieve accurate volumetric fills due to the fact that the volume of the cylinder never changes from cycle to cycle. Once product is in the cylinder, the piston provides the extra push to help efficiently fill thicker products. Different volumes can be achieved not only with different cylinder and piston sizes, but also by setting the machine to perform partial strokes, allowing one piston to fill a range of container sizes.

While there do exist exceptions to the rule, gravity filling machines will typically be used to achieve an accurate volumetric fill for low viscosity products, while pump and piston fillers add the extra push to efficiently handle higher viscosity products. For those that require a method other than filling by volume, such as fill-to-level or net weight, other options exist for thick and thin products as well.

To learn more about any of the filling machines manufactured by Liquid Packaging Solutions, or for assistance in identifying the best filling solution for your own project, contact LPS today to speak with a Packaging Specialist.