Pre-packaged (Pre-pack) It is a low-cost, high-performance milk and beverage packaging format invented by the French company Bailleul (now part of Switzerland’s Tetra Pak). Typically made from co-extruded film rolls consisting of either three layers (PE/black-and-white film/PE) or five layers (with the addition of nylon and an adhesive), this packaging boasts excellent barrier properties, light resistance, and freshness-preserving capabilities. Thanks to its cost-effectiveness, it is widely used in the dairy and beverage industries.

Overview of the Bally Package Filling Machine

The Bally-pack filling machine is an automated piece of equipment that uses pre-made composite film rolls to automatically perform a series of processes—including bag making, filling, sealing, and cutting—on the machine itself, ultimately producing independently packaged retail products.

I. Main Features

Cost-effective The equipment costs and packaging material costs are relatively low, making it an ideal choice for dairy beverage companies.

Flexible and diverse By changing the film roll and molds, it is possible to produce packaging with different capacities (such as 200ml, 250ml, 500ml, 1L) and various shapes (such as back-seal, gusseted, or three-dimensional packages).

Save space Using roll film as a raw material significantly reduces storage space and saves warehouse capacity compared to pre-formed packaging (such as plastic bottles).

High degree of automation From film feeding, date printing, molding, filling, sealing and cutting to finished product output—all processes are fully automated, requiring only 1-2 operators and delivering high production efficiency.

Good freshness retention performance The packaging film has excellent barrier properties and can effectively extend the product's shelf life.

II. Main Working Principle and Workflow

Its core workflow can be summarized in the following steps:

Film Conveying and Date Printing The equipment’s traction mechanism unfolds and conveys the composite film roll. Before forming, a coding machine or laser marking machine prints information such as the production date, shelf life, and batch number onto predetermined locations on the film.

Forming and Longitudinal Sealing The film is rolled into a tubular shape by a forming device (such as a collar-forming machine). At the same time, the longitudinal sealing unit applies heat and pressure to the film’s longitudinal seam, firmly sealing it to create a continuous tubular package.

Material filling The tubular film moves downward into the filling area, where the filling valve precisely injects a measured amount of liquid product (such as milk, juice, or beverages) into the film tube. The filling process is typically carried out below the liquid level to minimize foam formation.

Transverse sealing and cutting This is the most critical step. The horizontal sealing device clamps the film tube above the liquid surface while simultaneously performing two actions:

Sealing Heat and press the top of the current package and the bottom of the next package to form a lateral seal.

Cut off Cut the film between the two horizontal seals to separate the previously filled individual package.
The sealing effect directly affects the package's seal integrity and bag leakage rate.

Finished product output The individually packaged bags that have been cut are conveyed by a conveyor belt and can be packed into boxes either manually or by robotic arms.

III. Main Categories

According to the degree of automation and structure, they are mainly divided into:

Straight-line filling machine The filling station and the sealing and cutting station are arranged in a straight line. The structure is relatively simple, the speed is slower, but it is stable and reliable.

Rotary filling machine It adopts a rotary structure, with the filling and sealing/cutting stations completed simultaneously during rotation. It features extremely high speed and efficiency, making it a mainstream high-speed model in modern production.

IV. Core Components

A typical aseptic filling machine typically includes the following systems:

Rack and Transmission System The main structural framework and power core of the device.

Thin-film traction and conveying system Including the film frame, tension control device, guide rollers, and more.

Forming and Sealing System Including the forming device, longitudinal sealing heating block and pressure roller, as well as the transverse sealing mechanism.

Filling system Including the material tank, metering pump, filling valve, and control system.

Electrical Control System The PLC (Programmable Logic Controller) serves as the brain, working in conjunction with the touchscreen (HMI) to enable human-machine interaction, control the operation of the entire device, set parameters, and perform fault diagnosis.

Clean-in-Place (CIP) system Modern equipment is equipped with Clean-In-Place (CIP) functionality, ensuring that the equipment meets food hygiene and safety standards.

Auxiliary equipment Such as coding machines, conveyor belts, exhaust systems, and so forth.

V. Application Fields

Mainly used for Liquid food Sterile or ambient temperature filling, for example:

Dairy products UHT milk, yogurt, flavored milk, and dairy beverages.

Beverage Juice, tea beverages, plant-protein beverages, and functional beverages.

Other Seasonings such as soy sauce, vinegar, and cooking wine, as well as beverages like soy milk and fruit jam.

VI. Development Trends

Speeding up The speed of rotary-type machines continues to increase, reaching up to tens of thousands of packages per hour at the highest.

Intelligentization Integrates more advanced sensors, machine vision, and Internet of Things (IoT) technologies to enable remote monitoring, data analysis, and predictive maintenance.

Purification The application of clean filling technology is becoming increasingly mature, enabling the production of products that require no preservatives and have longer shelf lives.

Flexibility It can quickly switch between different packaging specifications and film rolls, adapting to the market demand for small batches and multiple product varieties.

Green and environmentally friendly Adapting to environmentally friendly packaging materials that are recyclable and biodegradable is an important development direction for the future.

In summary The bag-in-box filling machine is a liquid packaging equipment with mature technology, high cost performance, and wide-ranging applications. Through a highly automated process, it transforms a roll of film into individual, liquid-filled pouches—serving as a crucial piece of infrastructure that supports the modern fast-moving consumer goods industry, particularly the dairy beverage sector.