Liquid Filling Equipment
Liquid Filling Equipment needs are many and diverse. Ranging from startup companies with needs for semi-automatic liquid filling equipment to high speed packagers we can fulfill the requirements for your situation.
But in addition to meeting speed requirements for your production we need to match your needs with the right type of liquid filling equipment. Just to wet your appetite, so to speak, there are many types of liquid filling machines.
Types of Liquid Filling Equipment
Siphon Filler (also Syphon Filler)
Among the simplest and most ancient of all fillers, a siphon filler has a tank with a float valve connected to the supply tank. Tubes running sort of like an inverted J run into the tank and over to the other side. Simply start a siphon and adjust bottle fill height to the level of the tank and voila, you are now running a syphon filler. They are not speedy, but work quite well for free flowing liquids.
With the invention of the vacuum pump the vacuum filler followed shortly after. Simply draw a vacuum on an overflow container and attach hose to a filling head and from the head to the product. Product self primes when the bottle neck is sealed off and product fills to the level of the vacuum return to the overflow. Basically the bottle becomes a trap for the liquid. Since the invention of plastic bottles vacuum fillers are not common today. However they are still very effective on glass bottles and are particularly in common use for products like nail polish.
Gravity Fillers are still a commonly used type of liquid filling machine. There is even a variation known as Gravity-Vac (vacuum) that combines gravity with vacuum. Gravity fillers have an elevated tank which holds the product, the fill tubes open when inserted into the bottle and product flows into the bottle and overflow back into a recirculation tank below the bottle height which is then pumped back into the elevated tank. Vacuum was added to pull back drips. Gravity fillers are very effective for foamy products and are commonly used in big plants for filling non-carbonated beverages and water.
Pressure filling machines 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.
Counter Pressure Fillers
These are liquid filling machines unique to the carbonated beverage industry which includes beer, soda and any sparkling beverage or wine. Busch Machinery does not sell counter pressure fillers, but we will still explain this complicated type of filler. The heads for this type of filling consist of 3 parts: Vent, CO2 pressurizer and fill tube. The head seals and the Vent and CO2 pressure valves are opened. The air in the bottle is forced out of the bottle and is replaced with the heavier CO2. The vent is then stoppered down and product from very specialized heads forces the chilled carbonated liquid down the sides of the container in a sort of swirl pattern to minimize foaming. Once the fill height is reached the vent completely closes at the same time the product is cutoff. Many people mistakenly think that the CO2 counter pressure is the carbonating process, but carbonizing is a bit more complicated than that. The purpose of the CO2 is to keep the already existing carbonized beverage in solution and to minimize foaming.
Piston Filling Machines
The concept of a piston filler is fairly simple: pull in product on the back stroke and displace it into the container on the forward stroke, just like positive displacement pumps. Shorten or lengthen the stroke and you get different fill volumes. But there are actually two different types of piston filling machine, check valve types and rotary valve types.
Check Valve Piston Fillers
Check valve piston fillers are basically liquid filling equipment with one-way valves that open and close by the force of the liquid (and maybe some light spring action). On the back stroke the outlet valve is force shut while the inlet valve is forced open. On the forward stroke (this fills the bottle) the opposite takes place. One advantage of this type of filler is that it can be self priming on low viscosity liquids. Piston filling is among the most accurate types of filling available since it displaces the same volume every stroke. The limitations of check valve piston filling are that they only handle liquids to a light lotion consistency and will foul if there are any particulates in the solution.
Rotary Valve Piston Filler
Rotary valve piston fillers are among the most accurate and versatile type of liquid filling equipment available. Salad dressings, peanut butter, potato salad, oils and much more are filled with this type of filling machine. Rotary valve piston fillers have a hopper located above the rotary valve. The rotary valve itself is a cylinder with a large nearly 90 degree section cut out in the middle. On the back stroke the valve opens between the hopper and the cylinder then, just before the forward stroke it rotates 90 degrees to open between the cylinder and the discharge to the container to be filled. Depending on the size of the rotary valve, solids in suspension as large as a one inch cube can pass through the valve.
Servo Driven Pump Fillers
With the cost of servo drive controls coming way down over the last 20 years more and more uses for filling have come into play. Gear pump fillers is one type of application that has become very popular, although you must be sure that the pumps are sanitary pumps if you do foods, cosmetics or pharmaceuticals. The advantage of the gear pump is that you can fill almost any size product without need for change parts (although this still has limitations). At Busch Machinery we still think the jury is out on this, as piston fillers can still fill with as good or better accuracy, although with not quite as large a range..
Peristaltic Servo Driven Pumps
A peristaltic pump works by placing tubing into the pump which then has rotating rollers that alternately squeeze and relax the tubing to force the liquid forward. This type of system works well in pharmaceutical environments or anywhere that you want absolutely no chance of cross contamination. Simply throw away the tubing at the end of a run.