Liquid flexible packaging, with its advantages such as low cost, convenient transportation, and strong visual appeal, is increasingly being used in fields including dairy products, sauces, beverages, liquid seasonings, food, and daily chemical products. However, the characteristics of liquid materials—such as their tendency to leak and difficulty in sealing—place extremely high demands on flexible packaging equipment. As an expert in liquid packaging solutions, Said Packaging has specially prepared this guide to help you accurately select the most suitable liquid flexible packaging equipment.

Liquid flexible packaging machines primarily refer to vertical packaging equipment used for packaging bags (rather than bottles or drums). These machines automatically perform the entire process—from film roll to bag making, metering, filling, sealing, and cutting—all in one continuous operation. Choosing the wrong machine can lead to a host of issues, such as poor sealing, stringing and dripping, and package deformation. Therefore, we strongly urge you to conduct a comprehensive evaluation based on the following key aspects:

I. Physical Properties of Materials

This is the cornerstone for selecting equipment configurations and is more demanding than the requirements for ordinary granular materials.

Viscosity and fluidity: This is the primary consideration.

Low-viscosity liquid (Such as mineral water, soy sauce, and vinegar): These products have good fluidity and are easy to fill; however, they place high demands on the sealing performance of equipment and precise control of the sealing process at the moment of closure to prevent splashing.

Medium-to-high viscosity and easy-to-draw liquids ( (For products such as ketchup, honey, shampoo, and detergents): It is essential to select a filling valve equipped with an anti-drip device (such as a back-suction function) to effectively break the liquid stream and ensure that the bag opening remains clean. The filling pump must be selected based on the characteristics of the material being filled.

Corrosivity and Hygiene Grade Does the material contain acids, alkalis, or salts? For food and daily chemical products, all components that come into contact with the material—such as料缸 (material tanks), pipelines, and filling valves—must be made of food-grade 304 or 316L stainless steel to ensure corrosion resistance and freedom from contamination.

Does it contain particles or require refrigeration? If the liquid contains pulp, particles (such as chili sauce), or if the product is prone to oxidation (such as premium juices or oils), you should choose a hopper equipped with a stirring function to prevent sedimentation.

II. Production Capacity and Automation Goals

The scale of production directly determines the level of equipment investment and automation.

Packing speed: Do you expect a production rate of 40–60 bags per minute, or even 80–120 bags per minute—or higher? High-speed production requires a servo drive system with extremely high stability and a highly precise film-drawing mechanism.

Degree of automation:

Basic fully automatic: The equipment automatically completes bag making, filling, and sealing/cutting. It is suitable for small-batch, multi-variety production.

Fully automatic connection: Combined with automatic feeding machines, finished-product conveyor belts, and even robotic palletizing systems, this creates a fully automated production line suitable for large-scale, single-variety mass production, maximizing efficiency.

III. Packaging Forms and Sealing Technologies

For flexible packaging, the shape of the packaging bag and the quality of the seal are critical to success or failure.

Packaging bag type:

Back-sealed bag (three-side sealed): The most common bag type features a vertical seal on the back, providing a flat package that is suitable for most liquid products.

Side-sealed bag: Also known as a Tetra Pak, it is one of the most common packaging formats in the dairy and beverage industries.

Sealing System: This is liquid flexible packaging. Core technology 。

Sealing pressure and temperature: It is essential to ensure that the seal is sufficient. Pressure and uniform temperature To penetrate the sealing area that may be contaminated by liquids, forming a strong seal and preventing leaks.

Sealing material compatibility: The material and thickness of your packaging film (such as PE, PET/AL/PE, CPP, etc.) must be compatible with the heat-sealing temperature and pressure of the equipment.

IV. Core Performance and Ease of Maintenance of the Equipment

This is about the long-term stable operation of the equipment and its total cost of ownership.

Drive system: Equipment that combines servo drives with pneumatics far surpasses mechanical systems in terms of precision, speed, and stability, making it particularly well-suited for high-demand liquid packaging applications.

Cleanliness and Maintenance Design:

Quick-release structure: Can components such as the filling valve,料缸 (料 cylinder), and pipelines be quickly disassembled without tools, facilitating thorough cleaning and disinfection? Does it support CIP?

Waterproof rating: Do the equipment’s electrical cabinets and main motors have good waterproof performance to withstand the humidity and potential liquid splashes in the production environment?

Materials and Processes: Whether the device’s body is sturdy and whether key components are from well-known brands directly determine the device’s lifespan and failure rate.

Said Packaging's liquid flexible packaging solutions

Addressing the complex challenges of liquid flexible packaging, Said Packaging ( www.saidepack.cn ) launched multiple Series of Vertical Liquid Packaging Machines Its core advantages include:

Anti-drip filling system: Effectively solves the issues of stringing and dripping in medium- to high-viscosity liquids, ensuring clean bag openings and secure sealing.

Highly Adaptive Design: Combines servo and pneumatic technologies, PLC system, modular structure, food-grade stainless steel components, date printing functionality, and more.

Excellent sealing quality: With precise temperature control and pressure regulation, we ensure that each bag is sealed flawlessly—even at high speeds.

Humanized Operation and Cleaning: The human-machine interface is user-friendly, and key components feature a quick-release design that is compatible with CIP systems, significantly reducing cleaning difficulty and downtime.

Conclusion

Choosing the right liquid flexible packaging machine involves a comprehensive trade-off among material characteristics, production requirements, packaging formats, and equipment performance. We strongly recommend that you... Bring your actual product and packaging materials. , personally visit the Said Packaging Factory to conduct Free trial machine Witness firsthand the operational performance of the equipment and the quality of the packaged finished products. Let Said Packaging’s professional team be your strong ally in boosting production efficiency and product quality.