Filling machines are essential in the food, beverage, and non-food industries, ensuring that products are packaged efficiently, accurately, and hygienically. The choice of filling technology impacts not only the final product quality, but also production speed, format flexibility, and operating costs. Each technology has unique characteristics that make it suitable for specific products, container formats, and production environments.

From still drinks to viscous sauces, from carbonated beverages to oils, choosing the right filling method ensures optimal performance, waste reduction, and consistent quality. Among the various solutions available, this guide focuses on four key technologies: flow meter filling, level filling, load cell (net weight) filling, and mechanical volumetric filling.

Each method differs in the way it measures and doses the product inside the container. In the following sections, we will examine each one in detail, highlighting how it works, its advantages, and its ideal applications. Understanding these differences is crucial to identifying the most suitable solution for any production line—whether the priority is absolute precision, maximum speed, or operational flexibility.

Flow meter filling

Flow meter filling technology relies on magnetic flow meters to measure the exact product volume dispensed into the container. Most systems use either electromagnetic or mass flow meters, which deliver a high level of precision, minimize waste, and ensure consistent, uniform filling.

One of the main strengths of this technology is its flexibility. Flow meter fillers can handle a wide variety of products, from carbonated to still beverages, as well as liquids with both high and low viscosity. Product changeovers are fast, making them ideal for production lines with frequent format changes. This versatility also extends to different container types, including glass bottles and jars, PET, PE and HDPE bottles, aluminum cans, and more.

Hygiene is another important advantage. The streamlined design of flow meter systems minimizes contamination risks and simplifies cleaning operations, an essential factor for sensitive products such as dairy-based drinks or fruit juices.

From a performance standpoint, flow meter fillers combine high precision with high-speed operation, making them suitable for large-scale industrial environments. They are the ideal choice when the goal is not to fill to a visual level but to deliver the exact required volume into each container, regardless of its shape or transparency.

Level filling

Level filling technology ensures that each container is filled to the same height (the so-called fill point), compensating for minor variations in container capacity.

The principle is straightforward: the liquid flows into the container until it reaches the preset height, at which point the valve automatically closes. This guarantees a uniform and consistent fill level, even if the actual container volume varies slightly.

Its greatest advantage is aesthetic uniformity. Consumers often judge product quality based on visual appearance, and a consistent fill level conveys a premium, reliable image. For this reason, level filling is widely used in the beverage industry and for products packaged in transparent containers such as glass or PET bottles.

The technology is suitable for both still and carbonated drinks and can operate at very high production speeds. Level fillers can also be configured for cold, ambient, or hot filling, with varying degrees of automation. Their simple and robust design makes them particularly reliable for continuous long-term production with minimal maintenance.

One limitation is that this technology does not compensate for variations in container capacity, meaning the actual product volume may differ slightly from one unit to another. While generally acceptable for most beverages, it is less suitable for products where the exact volume must be guaranteed due to regulatory or cost constraints.

Load cell (net weight) filling

Load cell, or net weight, filling doses product by directly measuring its mass inside each container. High-precision electronic load cells continuously monitor the weight during filling, closing the valve automatically as soon as the target weight is reached. This ensures highly accurate and consistent dosing.

This method is especially advantageous for high-value products, where even small overfills can significantly impact costs. It is also ideal for liquids with variable density—such as oils, syrups, sauces, or detergents—since it is not affected by temperature or viscosity changes that may compromise volumetric measurements.

Another strength is versatility: weight fillers can easily adapt to containers of different shapes and sizes without requiring major adjustments. They also guarantee compliance with weight regulations across various markets, preventing legal issues or penalties related to underfilling or overfilling.

Operationally, they deliver two key benefits: significant waste reduction, supporting sustainability goals, and superior accuracy compared to other technologies. Their only trade-off is slightly lower production speed, as each cycle requires precise weighing.

Modern weight fillers are often integrated with digital monitoring and quality control tools, making the process even more reliable and traceable. For these reasons, load cell filling is the ideal solution when protecting product value and ensuring maximum accuracy are more important than line speed.

Mechanical volumetric filling

Mechanical volumetric filling doses a fixed volume of product into each container, regardless of its shape or size. This is usually achieved through a piston-and-cylinder unit, which draws in a predefined volume of product into its chamber and then transfers it into the container, ensuring consistent and uniform filling.

This technology is highly versatile, capable of handling a wide range of viscosities—from thin liquids to dense pastes, and even products with solid particulates. For this reason, it is widely used in the food industry for products such as sauces, jams, spreads, dairy items, and ready-to-eat meals.

Volumetric filling combines accurate dosing with good operating speeds. Its greatest advantage lies in handling complex products, such as biphasic recipes with particulates or very viscous formulations, which are often challenging for other filling methods.

Another benefit is its adaptability: format changeovers are quick and straightforward, making it ideal for short production runs or packaging with high variability.

Overall, mechanical volumetric filling offers a balanced solution in terms of speed, flexibility, and reliability. It can also be seamlessly integrated into hygienic line designs and is compatible with automated cleaning-in-place (CIP) systems.