Attività

Pressure filling machines, or automatic can sealing machine, have their tanks below the bottom of the bottle. The tank flood feeds a pump (generally a centrifugal pump but also positive displacement pumps for thicker liquids) which then flows directly into the bottle until it reaches the fill level at which point excess product flow directly back into the tank. When filling plastic bottles the pump must be turned off (always for positive displacement pumps) before removing the filling tubes to allow the bottles to return to normal size (they swell under pressure) and drain off excess liquid. The big advantage of pressure fillers is that bottles fill more quickly so fewer heads (and space) are required and higher viscosity products can be filled. The disadvantage is that foamy products must be filled at slower pump speeds than normal, and this will work only if the foam settles out fairly quickly.