What is the Working Principle of a Sachet Filling and Sealing Machine?

Single-dose packaging has become the norm across a wide range of industries—food, pharma, cosmetics, and chemicals. The sachet is usually how it’s delivered.

Behind that sachet is one machine running a continuous sequence: film in, pouch formed, product filled, sealed, cut. No manual handoff between steps. Sachet filling and sealing machines have become standard equipment partly because the demand for compact, single-use formats keeps growing—and partly because the alternative, doing any of this at volume without automation, doesn’t hold up.

1. Sachet Filling and Sealing Machine Working Principle

The sachet filling and sealing machine operates as a continuous motion system driven by PLC control and servo motors. Its basic workflow includes film unwinding, pouch forming, accurate dosing, filling, heat sealing, and final cutting.

1.1 Film Feeding and Forming System

The process begins with roll film feeding. Under servo control, the film maintains stable tension during high-speed operation to ensure accurate alignment. The film is then shaped into a tube through a forming unit, preparing it for filling.

Typical working parameters include:

• Speed: 40-120 bags/min
• Tension deviation: within ±0.5%
• Film types: PET/PE, laminated or composite films

This stage ensures that the sachet filling and sealing machine runs smoothly without film deviation or misalignment.

1.2 Accurate Dosing and Filling System

The dosing system is the core of the sachet filling and sealing machine, as it directly affects product accuracy and consistency. Different materials require different filling technologies.

For liquid and viscous products such as honey, energy gel, or sauce, piston pumps or anti-drip filling systems are commonly used to prevent leakage or stringing during operation.

For powder products such as protein powder, coffee powder, or probiotic powder, an auger filler system is used. Controlled by servo motors, it delivers accurate powder dosing with an error range within ±1%.

1.3 Sealing and Cutting System

After filling, the sachet filling and sealing machine performs the sealing process. The seal itself is a heat process. Jaws close on the film to make them bond together. As different films have different bonding characteristics, the sealing temperature varies.

The setting range for the sealing time is 0.8-1.2 seconds. This can ensure strong adhesion. After sealing, the cutting system separates the continuous film into individual sachets, completing the final packaging output.

2. What Materials Can Be Filled by a Sachet Filling and Sealing Machine

The sachet filling and sealing machine supports a wide range of materials, including liquids, powders, and selected mixed formulations, depending on machine configuration.

2.1 Liquid and Gel Materials

Liquid products are widely used in sachet packaging, such as honey, energy gel, seasoning sauces, and liquid supplements. These materials often have different viscosity levels, requiring stable and anti-drip filling systems.

ZONESUN ZS-FS240L Vertical Automatic Running Energy Gel Shaped Pouch Packing Machine. This model is designed for liquid and viscous materials. Its main features include:

• Servo-driven film pulling system for stable operation
• Adjustable sealing temperature and time for different films
• Heating and mixing hopper for high-viscosity products
• Supports 1-100ml sachet filling range
• Touchscreen control system with customizable language

This type of sachet filling and sealing machine features stable dosing and clean sealing performance. It is suitable for packaging sticky or high-viscosity liquids.

2.2 Powder Materials

Powder materials include food powders, cosmetic powders, drink mix powders, chemical powders, medicine powders, and so on. The main challenge is dust control and dosing stability.

A representative model is the ZS-FS240V Vertical Powder Sachet Packing Machine with Vacuum Feeder. This sachet filling and sealing machine features a vacuum feeding system for the automatic transport of powder and an auger dosing unit for the precise metering of fine powder.

Key features include:

• Automatic vacuum powder feeding system
• Auger dosing system for high accuracy
• Full automatic pouch forming, filling, sealing, and cutting
• Capacity: 2100-2700 pcs/hour
• Supports flat, round-corner, and custom pouch shapes
• Continuous sealing system for stable output

It is widely used in protein powder and functional nutrition packaging, improving efficiency and reducing material waste.

2.3 Mixed and Special Materials 

In addition to single-type materials, the sachet filling and sealing machine is increasingly used for mixed and special industrial products. These applications require higher machine precision and often involve multiple dosing systems working together in coordination.

Typical applications include:

• Nutritional supplement powders (mixed with fine granules)
• Instant drink formulas (sugar, creamer, and flavor powder blends)
• Chemical additives (liquid and powder composite systems)
• Pharmaceutical single-dose sachet packaging

In these cases, a sachet filling and sealing machine must ensure accurate ratio control and stable feeding to maintain product consistency during continuous operation.

3. Factors to Consider When Choosing a Sachet Filling and Sealing Machine

When selecting a sachet filling and sealing machine, several key factors should be considered:

• Material properties
  Including viscosity, flowability, particle size, and whether the product is corrosive or sticky, as these directly affect the filling system selection.
• Production capacity
  Medium production lines typically run at 40-80 bags per minute, where efficiency and stability must be balanced.
• Packaging specifications
  Such as pouch width, length, and filling volume range, which determine whether standard models are sufficient or customization is required.
• Automation level and functions
  Including touch screen control, automatic date printing, conveyor integration, and alarm systems, which help improve efficiency and reduce manual operation.

Conclusion

The sachet filling and sealing machine combines forming, dosing, sealing, and cutting processes in one fully automatic production, enhancing production efficiency and quality.

Due to the increasing requirement for single-dosing packages, its application range includes the fields of the food industry, pharmaceutical industry, and cosmetic industry.

ZONESUN offers sachet filling and sealing machines for liquid products, powder products, and other products. If you need help choosing your machine, please contact us at ZONESUN.