Packaging Thick Products - A Brief Overview
Packaging free-flowing liquids such as water and other beverages can often be done using one of several different filling methods. But when viscosity rises and products don't flow quite as easily, packagers must look outside popular choices such as overflow and gravity type filling machines. Though these machines can work for some medium viscosity products, items such as honey, paste, thick gels and others simply require other solutions. Below we will look at some options for packaging a thick product.
Outside of a liquid filling machine, the equipment used on a packaging line for thick products will not really differ from the machinery on any other packaging line. For instance, the type of capping machine used will be dependent on the type of closure, that is, the package rather than the product. The same is true for labeling machinery and other components of a packaging line, the package itself will define the machinery rather than the product. However, the filling machine will actually handle the product, and therefore both package and product will affect the filling equipment used on any given line.
In general terms, thick products that do not flow freely require some assistance that would not necessarily be needed with thinner, or lower viscosity products. Two of the most popular ways to provide this assistance are through the use of pump fillers or piston fillers. Pump filling machines can use a number of different pumps to match the product and packaging project. Pump machines can provide a time based fill, meaning the pumps will turn on and off for a set amount of time with each fill cycle. However, these machines can also be set to provide a pulse based fill. As an example, when using a gear pump, each pulse may equal one full turn of the gear, or a fraction of a turn. In either case, the pump helps the thicker products flow through the product pathway and into the waiting containers in a manner that can remain both consistent and reliable.
Piston fillers are ideal for the thickest of thick products, as well as for products that contain particulates or chunks like tomato paste or gritty hand soaps. The piston filler pulls product into a cylinder and, once full, the piston pushes the product out into the waiting containers. These machines are highly accurate in that the cylinder will fill with the same amount of product with each stroke. Also, the wide open space in the cylinder is what allows particulates to pass through without clogging tubing, nozzles or other components of the filling machine.
There are, of course, other methods for filling thick products, including custom manufactured filling machines. However, in a majority of cases, either the pump filler or piston filler will be used to get the job done. For more information on the different types of filling machines, visit the filling section of our website.