Last week we spoke about the Overflow Filler, arguably the most produced filling machine at NPACK last year due to the level fill and ease of use. The overflow filler, however, works best with free-flowing products with lower viscosities. For thick, high viscosity products, a different solution becomes necessary. In 2017, NPACK manufactured almost as many piston fillers as overflow filling machines, for a wide variety of products.
While piston fillers can handle thin liquids as well, these machines are ideal for thick liquids and pastes, semi-solids and products with large particulates. From honey and toothpaste to sauces and jams with chunks of veggies and fruits, piston filling machines can help to prepare a range of items for the shelf. In general terms, a piston retracts during each fill cycle during which time product will be pulled in to the empty cylinder. To fill the bottles, the piston returns to the cylinder, pushing product in to the waiting bottles. Given the fact that the volume of the cylinder will not change from cycle to cycle, the piston filler offers a highly accurate volumetric fill. These machines can be manufactured to work both automatically and in a semi-automatic manner, meaning they are useful for packagers with any production size.
Automatic piston filling machines, similar to the overflow filler, will use an indexing system and Programmable Logic Controller (PLC) with an easy to use touchscreen Operator Interface. Power conveyors continuously supply bottles to the machine for filling, typically leaving the operator of the filler or the packaging line to simply re-supply bulk product once production begins. Some set up will be required, but a majority will be bypassed using the Recipe Screen found on the Operator Interface, which allows for most of the settings to be recalled for any given bottle and product combination (these settings will be factory set where bottles and product are supplied to NPACK for testing of the equipment!).
Though available in a number of different designs, the most popular of the semi-automatic piston fillers is the tabletop version. While the retracting piston principle remains the same, tabletop models typically work with a single head and require a little more operator assistance. Those using the tabletop machine will place the bottle under the nozzle and activate the fill cycle with a switch. Once filled, the operator must remove the filled bottle and place the next under the nozzle. While slightly more labor-intensive than an automatic machine, the tabletop filler is more economical while still offering better speed and accuracy over hand filling products.
To learn more about these liquid filling machines, visit the Piston Filler section of the website or contact an NPACK Representative today.