6 Mainstream Edible Oil Filling Machine Types and Their Filling Methods.

Okay, this is a topic that comes up all the time, and for good reason. When you’re looking at spec sheets, you’ll see all these different terms for how a machine measures out your oil—volumetric, net weight, overflow—and it can sound way more complicated than it actually is. I promise you, it’s not.
In reality, there are just a few core ways these machines work their magic. Each one is a tool designed for a specific job. Let’s break them down, simple as can be.

Volumetric Filling.

Volumetric filling is a method designed to deliver a precise, consistent quantity of product into every container. The most common type I see in the field is the piston filler. So, how does it actually work? Imagine a large syringe. A piston inside a cylinder pulls back, drawing a specific volume of liquid from a supply tank or hopper into the cylinder. Once the cylinder is full, a valve switches, and the piston then pushes forward, dispensing that exact volume of product through a nozzle and into your container. The key here is that the fill volume is controlled mechanically by the length of the piston’s stroke, a longer stroke means more product. This method is incredibly reliable for ensuring each package contains the correct amount of product, which is vital when the labeled net weight or volume is a legal requirement. When a piston isn’t the right fit, pump technologies take over. A gear pump is ideal for thick, clean oils—it uses two intermeshing gears to deliver a steady volume at low cost. For more delicate products or those with solids, like jams or creams, a lobe pump works better, as its rotors move the product gently without crushing particles. When handling hazardous or ultra-pure liquids, the magnetic drive pump is the top choice: magnets spin the impeller through a sealed barrier, eliminating shafts and leaks. In every system, the final fill comes down to precisely controlling pump speed and run time.

Weighing Filling.

When your product’s value is tied directly to its weight. Such as Uniform density oil, coffee beans, snack foods, or expensive powders. I always think of this as the most direct way to protect your profit margin. The process is straightforward: product is fed from a supply hopper, usually by a vibratory feeder, into a weigh bucket. But what’s the key component here? It’s the load cell. This is just a high-precision sensor that measures the weight in the bucket in real-time. Once the system’s controller sees that the target weight has been reached, the feeder stops instantly, and the bucket opens to drop the product into the container below. This method completely ignores the container’s volume, focusing only on delivering the exact weight you promised your customer, preventing costly product giveaway with every single fill.

Overflow Level Filling.

Overflow filling is all about one thing: perfect shelf appeal. When you have products in clear bottles, customers expect them to look identical. This method guarantees that, even if the internal volume of your bottles varies slightly. The magic is in the nozzle, which has two ports. As the nozzle lowers, it creates a seal over the bottle opening. Product flows in through one port, and when the liquid reaches the desired height: a level physically set by the depth of the second “return” port, any excess product is pushed out through that return and sent back to the supply tank. This is why I recommend it for any thin, free-flowing liquid that foams, like soaps or window cleaners. The overflow action effectively eliminates foam, leaving a clean, consistent fill line every time.

Flow Meter-Based Filling.

For operations that demand high speed and repeatable accuracy, flow meter filling is a top-tier choice. This is a purely electronic method of volumetric filling that ditches mechanical pistons for advanced sensors. Here’s the breakdown: liquid is pumped from a supply tank and passes through a specialized flow meter right before it gets to the filling nozzle. That meter measures the volume of liquid passing through it in real-time. The machine’s controller gets this data and, once the exact target volume has been dispensed, it sends an electrical signal that shuts the nozzle off instantly. Different liquids require different sensors: electromagnetic meters for conductive liquids like juice, or mass flow meters for products where density changes with temperature. It’s a clean, fast, and incredibly precise system that’s a favorite in the modern beverage industry.