[VIDEO] VFFS machine maintenance: How to set up automatic film tracking

Scott Miller

Welcome to our new video series: Packaging machine maintenance tips of the month!

Each month, one of our expert Viking Masek technicians will walk you through a common packaging machine maintenance task.

Today we're showing you how to set up automatic film tracking on a vertical form fill seal (VFFS) machine.

What is automatic film tracking?

As film travels through a vertical form fill seal machine, many things can happen before it reaches the front of the machine where the film is formed into a bag shape. The film passes over a series of tension rollers, it can be slit, it can receive a printed date/lot code, and more. All of these different steps have a tendency to change the tension on the film, causing it to drift left or right of center. Off-center film will result in uneven or inadequate fin seals.

To prevent this, modern VFFS machines are equipped with an automatic film tracking sensor that automatically re-orientates the film so it is centered within the machine at all times.

What does an automatic film tracking sensor do?

An automatic film tracking sensor detects when the edge of the film drifts too far from center. It does this using 2 optical sensors, one focused on the film path, and another focused outside the film path. When it detects the film is not within an acceptable range between the sensors, the entire film carriage will shift left or right to bring the film back to center.

Advantages to automatic film tracking over a manual tracking process include less film and product wastage and more uptime.

How to set up automatic film tracking on a VFFS machine

  1. On the back of the VFFS machine, make sure the roll of film is centered on the film carriage. Place your tape measure against the film and measure to the inside of the carriage frame. Take these measurements from both sides of the film. They must be equal to ensure proper centering.
  2. Once you confirm that the film is centered, move to the HMI on the front of the machine.
  3. Make sure that the automatic film tracking is turned OFF.
  4. Run some film through the machine to check the position of the fin seal on the bag.
  5. Take a look at the fin seal. You are checking to make sure the top flap is over the bottom flap. This ensures that the sealant layer on the bag will not be exposed. If the sealant layer is exposed, it can cause the film to stick to the sealing dies.
  6. Once the fin seal is set up in the way you would like, turn the automatic film tracking ON by pressing the button on the touchscreen HMI. A green checkmark means it is ON, while a red circle with a line through it means it is OFF.
  7. View the sensor itself on the top of the machine. You can adjust the horizontal position by loosening up a bolt with a 13mm wrench. Move the sensor right or left to its new position, and then re-tighten the bolt.
  8. Make sure the film is in between the two lights coming off the sensor. From the top down, one of the lights must be focused on the film path, and one must be focused outside the film path.
  9. Return to the HMI on the front of the machine. Start the machine and run a few bags through.
  10. Look at the film to make sure the fin seal is still within an acceptable range. Once confirmed, the film tracking sensor is set up and you are ready to run!  

Troubleshooting film tracking problems on your VFFS machine

If your automatic film tracking sensor is on and your film is still drifting, it's time to investigate further. This issue can have multiple causes but is often caused by the film spindle being off-center in the film carriage or improper webbing of the film through the machine. If you have recently spliced your film, this can also cause issues with film tracking.

Learn how to troubleshoot common film-related issues >>

Watch more packing machine maintenance videos

Check out the other videos in our VFFS Maintenance Quick Tips series:

How to change the cutoff knife >>

How to change a vacuum pull belt on a high-speed machine >>

How to set up film registration & train photo-eye sensor >>

Stick to a comprehensive preventive maintenance plan

Machine preventive maintenance is one of the most important things you can do to ensure a long, productive life for your equipment. Download our comprehensive VFFS machine preventive maintenance planner for daily, weekly, monthly, and yearly recommended maintenance tasks:

Get your FREE VFFS maintenance planner >>