Gravity Filling Machine Principles

gravity filling machine

Gravity filling is the most basic form of filling. Gravity filling machines with effective Gravity Filling Machine Principles need less maintenance with their simple structure and operation features.

Operating Principles of a Gravity-Based Filling Machine

The supply tank, also called the filling bowl, is at the very top and middle of the machine. This machine fills containers by gravity. A stem is attached to the bottom of the bowl at each place where it fills a container. The vent tube is put into the bowl for filling until it’s above the level of the liquid. The platform raises the container until it hits the stem for filling. The container raises then until it touches the stem. This makes the valve for filling open. 

The container fills up with liquid when the valve opens. The air in the container goes through the vent tube and into the bowl above the liquid being filled. The liquid continues to flow even when the container is almost full. The air tube brings the extra water up to the same level as the water in the bowl. The vent tube is higher than the liquid level in the bowl, so no liquid from the container runs into it.

If the product is foamy, the foam will rise above the liquid level in the bowl in the vent tube. It will eventually run into the bowl if the foam is stable and won’t break down. As a result, foamy products don’t use gravity fillers very often. After the container is full, it moves out of the filling position and closes the valve at a set time. 

Filling with Gravity Filler

There are a few different ways to get the liquid out of the vent tube while it’s still in the stem. One container will often fill up and drain into the next. The air tube generally goes further than the bowl’s side or top for thick liquids. The outside end can be hooked to a pressure machine or a vacuum to pull liquid out of the tube. 

Gravity head pressure produces the bowl’s overall differential pressure. Normally, one psi or one to two feet of head. This means fillers can only quickly fill thick liquids using bigger stems. For the stem to fit, the neck of the container needs to be big; if it’s not, you must adjust the machine.

Electronic Systems in Gravity Fillers

Electronics apply to different types of gravity fillers. It has a stem with an open end for filling and a set bowl for holding liquids. The containers move slowly and irregularly along the filling line, stopping under the stems that hold the fillings. Inside each stem, a ball check connects to a long rod. At the end of the rod, a pencil-shaped magnetic block links to it and passes through a magnetic coil.

gravity filling machine principlesA sensor device picks up the container as it moves under the stem, like an electronic eye or limit switch. It turns off the conveyor and turns on the magnetic coil. The electric force makes the magnetic blocks rise, which moves the rod and ball check to lift from their positions within the stem.

If you change the size of the stem’s opening and turn on the time delay relay on the magnetic coil, you can control how much the filling is. Since this is a gravity filler, the hole in the stem must be smaller than the container’s width on the inside so it doesn’t leak. The bottle is put under the filling stem more securely when filling smaller containers. Take care of both the flow and the amount of the liquid.

Gravity Filling Machine

Lifting filling machines generally adjust the fill height from the bottle bottom to the liquid level. The container rises positively, and differences in total container height are adjusted for by higher or lesser seal pressure. Most rising container machines have a compression spring built into the part that lifts the tray. With this, the spring makes up for differences in the height of the container.

The filling is then from above the neck of the bottle to the surface of the liquid. When filling a container with square shoulders, it’s sometimes essential to control the liquid level from above so it doesn’t look like underfill.

gravity filling machine principles

Most of the plant’s vertical space in rising stem fillers comes from the stem. Typically, the fill level changes from the top of the bottle to where the liquid is. This is because gravity or a small amount of spring pressure pushes it down.

If the product has a liquid that evaporates quickly, like alcohol, it is crucial to control the height of the fill. In this case, the extra space could let dangerous gases build up, and if the container is kept in a warm warehouse, it could even blow up. So, the filling machine must be able to control the height of the fill. Most of the time, a fill height sensitivity of 1/32″ is reasonable.

Other Machines That Help Gravity Filling Machines

Several pieces of equipment take control of the containers as they come into the filling area. Some of them are star wheels, worm or screw sorters, and lug chains. Depending on the container, filling device, and product, they may be applicable together or separately.

Most liquid filling machines work continuously. Many devices have a huge rotating filling head that must be fed containers. This is possible with a flat-top chain conveyor that continually feeds a star wheel or leads screw. From here, the containers are filled. Star wheels separate the containers, so they are all under the stem for filling. They can work with many different containers, but they may need to go toward the star wheel for the best separation. Worm sorters move containers into a star wheel. They can be short and only near the machine’s input, or they can be the whole primary conveyor.

How much control there is over the container determines how long the worm gets. Worm sorters often start small and grow to their full size, like a wood screw. At the point where the high crest of the thread meets the root, this makes a continuous pocket. This pocket moves the container to where it needs to be on the filling machine by rotating. Most worm sorters specialize in a certain task.

In most cases, inclined conveyors and semiautomatic filling machines are the best candidates for installing lugged chains. Devices in this category may move continuously or occasionally. It is for the filling equipment’s nozzles or stems to fit tightly between the chain’s lugs. As an example, think about filling stems that are 4 inches apart. At the driving sprocket, you can change how the chain moves. Filling heads move around to change where they are. Proper management of containers, no matter what form it takes, is vital for the machine to work well.


In general, gravity filling means using the liquid’s own weight to fill the container. This is often through a timed feed from a tank above the filling heads. Eventually, a valve underneath the filling head opens, allowing a certain quantity of liquid to flow into the container. Low viscosity, homogeneity, and the lack of dispersed particles that might clog the heads are the desirable characteristics of the liquid.

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