Dripping, Splashing, or Stringing? The Filling Nozzle May Be the Problem

A filling line can be dispensing the right amount of product and still have a problem. Maybe a thin sauce splashes as it enters the container. A thicker product leaves a string behind after every fill. A salsa runs well until a piece of vegetable catches in the product path. Or the fill itself is accurate, but product keeps ending up on the rim of the container.

It is easy to look at those problems and blame the filler. But sometimes, the problem is happening in the last few inches of the process.

It All Changes at the Nozzle

The filler determines how much product is dispensed. The nozzle determines how that product actually leaves the machine and enters the package. And products behave very differently at that point.

Water does not fill like salsa. Salsa does not fill like fudge. And fudge does not behave like frosting, salad dressing, or a product containing large particulates. A thin liquid may move through the system easily but hit the container with enough velocity to splash. Slowing the machine down might help, but it can also sacrifice production speed without addressing the real issue. Sometimes, changing the way the product enters the container is the better answer.

Capillary, Diaphragm, and Inverted Cone Nozzles are examples of designs that can help control the flow of thinner products. Depending on the application, the right configuration can help create a smoother flow, reduce splashing, and improve cutoff.

As viscosity increases, however, the problem changes. A thick sauce, fudge, frosting, or paste may enter the container without splashing at all, but the challenge comes when the fill is supposed to stop. Instead of breaking away cleanly, the product can stretch or string, eventually dropping onto the container rim, conveyor, or an area that later needs to be sealed. For products like these, a Rotary Cutoff Nozzle can help create a more defined end to the deposit rather than relying on the product to naturally break away.

But viscosity still isn't the whole story. Take a smooth sauce and add chunks of vegetables, fruit, meat, beans, or other particulates. The liquid portion may behave almost exactly as it did before, but now every piece of product has to make it through the same path. Suddenly, opening size and product path matter just as much as flow and cutoff. The goal is no longer simply to fill the sauce—the complete product has to make it into the container.

That's why piston filling systems and nozzle configurations for particulate products need to be selected around what is actually moving through them, not simply whether a product is labeled "thick" or "thin."

The Product Is Only Half the Equation

Even after the product is understood, there is another variable: the package. Put the same product into a wide-mouth cup, a narrow bottle, a shallow tray, and a tall container, and the filling conditions change.

A nozzle that performs well filling from above may need to enter another container and fill from the bottom up to control splashing, foaming, or air incorporation. In other applications, the challenge may be appearance rather than splashing. When a thin liquid needs to reach the same visible level across containers, overflow filling can allow excess product to return through the nozzle once the desired level is reached.

The product hasn't changed, but the package has—and that can be enough to create an entirely different filling challenge.

Sometimes the Filler Isn't the Problem

That is why a filling problem should not automatically lead to the conclusion that the entire machine needs to change. If product is dripping, splashing, stringing, damaging particulates, or collecting around the container rim, it is worth looking closely at what is happening at the point of dispense.

At Volumetric Technologies, we offer standard and custom dispensing nozzles because there isn't one nozzle that makes sense for every product and package. The right solution depends on what is being filled, how that product behaves, where it needs to go, and what needs to happen when the fill stops.

Sometimes improving a filling application doesn't require changing the entire process. It requires getting the last part of the process right.

Because when it comes to filling equipment, the last few inches can have a major effect on the entire operation.