This tutorial is based on practical machine operation experience and is intended to help operators, maintenance technicians, and production managers correctly install packaging film and reduce common film threading problems during machine setup.
For different sachet packaging machine models, the position and structure of individual components may vary slightly. Always refer to the machine manual provided with your equipment.
Safety Precautions Before Threading Film
Before installing film onto a sachet packaging machine, operators should follow proper safety procedures to prevent equipment damage or personal injury.
Important Safety Checks:
- Confirm that all moving parts have stopped completely.
- Do not place hands near sealing rollers, cutting knives, or moving transmission parts while the machine is operating.
- Avoid touching heated sealing components immediately after machine operation.
- Make sure the film roll is installed securely before starting automatic operation.
Only trained operators or personnel familiar with the machine structure should perform film threading and adjustment procedures.
Correct film threading is an essential operation when setting up a sachet packaging machine. The packaging film must pass through multiple components, including the feeding rollers, film holding mechanism, slitting system, the vertical sealing mechanism, film pulling roller,rotary slitter, and horizontal sealing mechanism.
If the film is threaded incorrectly, the machine may experience problems such as film deviation, inaccurate bag forming, sealing failure, uneven cutting, or unstable operation.
Step 1: Install and Secure the Film
Before threading the film through the machine, first install the film roll correctly and fix the film on the air shaft.
- Place the packaging filmonto the air-expanding shaft.
- Install the support bracket to hold the film in position.
- Check that the film is stable and cannot move or fall off.
- Inflate the air-expanding shaft. Itwill expand and tightly fix the film core
A properly secured film roll prevents film movement and helps maintain stable film feeding.
Step 2: Thread the Film Through the Rollers
After fixing the film roll, start threading the film along the machine’s film path.
Pass the Film Through the Rollers
Follow these steps:
- Pull the film from the roll to start threading it.
- Pass the film through each roller in the correct order.
- You can move the lead screw to slightly loosen the film position. This small adjustment creates more space and makes the following threading steps easier.
- Pass the film through the pressure roller. Pull the film slightly to remove any looseness or slack. Keep the film flat and properly tensioned.
Before moving to the next section, make sure the film is not folded, twisted, or too loose.
Step 3: Thread the Film Through the Slitting Mechanism
After the film passes through the film holding mechanism, guide it into the slitting mechanism.
Align the Film With the Slitting Position
Follow these steps:
- Insert the film into the slitting mechanism.
- Check the position of the split film.
- Make sure the split film is aligned with the top point (apex) of the slitting mechanism.
If the film position is incorrect:
- Adjust the position of the slitting blade.
- Realign the film so that it sits correctly at the apex.
- Correct alignment ensures accurate film splitting during packaging production.
After adjustment:
- Pull the film slightly to remove any slack.
- Keep the film straight and flat.
- Continue threading the film toward the sealing system.
Step 4: Thread the Second Half of the Film Into the Sealing System
After the slitting process, continue threading the second half of the film.
Pass the Film Through the Sealing Components
Follow the sequence below:
- Pass the film through the remaining rollers.
- Keep the film flat and slightly tight.
- Open the sealing mechanism.
- Insert the film into the vertical sealing mechanism.
- Pass the film through the film pulling roller.
- Pass the film through the rotary slitter.
- Pass the film through the horizontal sealing mechanism.
During this process, avoid loose or wrinkled film. If the film is not flat, the machine may have problems such as:
- Uneven bag forming
- Poor sealing
- Incorrect bag cutting
Adjust the Rotary slitter
After the film passes through the Rotary slitter:
- Tighten the outer nut to the right.
- The cutter will move outward.
- This reduces pressure on the film and makes the next threading step easier.
Step 5: Thread the First Half of the Film Into the Sealing System
Now complete the remaining film path by threading the first half of the film roll.
Finish the Film Threading Process
Thread the first half of the film through the following components in sequence:
- Therollers
- The vertical sealing mechanism
- Film pulling roller
- Rotary slitter
- Horizontal sealing mechanism
Make sure the film remains:
- Flat
- Centered
- Properly tensioned
Adjust the Rotary slitter for Cutting
After threading is complete:
- Turn the outermost nut of the rotary slitterto the left.
- The cutter will move inward and press against the film.
- This allows the knife to cut the film correctly during operation.
The knife pressure can be adjusted according to:
- Film thickness
- Film material
- Cutting performance requirements
Final Check Before Starting the Sachet Packaging Machine
Before running the machine, check the complete film path:
✓ Film roll is firmly fixed on the air shaft
✓ Film passes through all rollers correctly
✓ Film is flat without wrinkles
✓ Film alignment is correct at the slitting mechanism
✓ Sealing units are threaded correctly
✓ Rotary slitter pressure is properly adjusted
After completing these checks, the sachet packaging machine is ready for the next film adjustment and production setup process.
Film threading is one of the most important setup procedures for a sachet packaging machine. A correct threading method ensures smooth film feeding, accurate cutting, stable sealing, and consistent bag production. Following this complete film threading tutorial will help ensure that your sachet packaging machine operates reliably and delivers high-quality packaging results.
