STRPACK's positive displacement pump filling machines are best suited for filling viscous products, but they can be used to fill thin products as well. These fillers can handle a wide range of container sizes, fill volumes, and product types; but they are most ideal for filling pastes, creams, lotions, and gels, in large volumes and at greater speeds than otherwise achieved with a piston filler.
While pump filling machines are typically used when dealing with a higher viscosity product, the truth is they can be employed for many items both thick and thin. The key is in choosing the correct pump for each individual product based on the product characteristics, the package, production speed and other factors. Below are some of the more common pumps used on these liquid fillers.
Gear Pumps
Gear pumps are a type of positive displacement pump, moving product through the teeth of the gear and into waiting containers. As the gears turn, product becomes trapped in the spacing, only to be pushed out as the teeth separate on the outlet side of the pump. While these pumps are typically used for thicker products, gear pumps can work with more free-flowing products as well, though there are usually better options depending on the product and needs of the packager.
Lobe Pumps
Like gear pumps, lobe pumps are a type of positive displacement pump that uses a rotary action to move product. Unlike gear pumps, a lobe pump will normally consist of about three lobes (versus the many teeth on the gear pump). Product is pushed throught the lobes in a manner similar to passing through the teeth of a gear pump. However, the extra space can be a benefit for products with small to medium particulates that may cause problems when passing through gears.
Progressive Cavity Pumps
Progressive cavity pumps move product using a rotor revolving inside of a stator. The rotor, being slightly smaller than the stator, creates gaps that push the product through the pump. Progressive cavity pumps will be used on a filling machine when extremely high viscosity products are in play, as the high output pressure assists in moving these products to the containers. Progressive cavity pumps may also be used when solids are present in a product.
Peristaltic Pumps
Peristaltic pumps use rollers to move product through tubes and into waiting containers on a liquid filler. The rollers contact and compress the tubing, forcing product to move forward through the tubing. These pumps are ideal for processes that need a sanitary fill (pharma, flavored food and beverage) as the product will not come in contact with the pump itself, but only the tubing, helping to avoid contamination. These pump fillers themselves will be manufactured so that the changing of the tubing is a quick and simple process.
While these pumps are more typically found on a liquid filler, there are many others that can be employed as well. Each project should be analyzed before manufacturing begins to ensure that the filling principle and pump chosen are the best for the job! For questions regarding pump fillers or any other bottle filling machine, browse our fillers page or contact a Packaging Specialist today.
