[VIDEO] VFFS machine maintenance: How to set up automatic film tracking on a stick pack machine


What is automatic film tracking?

As film travels through a stick pack 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 on the individual stick packs.

To prevent this, modern stick packaging 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?

The automatic film tracking sensor detects the location of the edge of the film with a set of two photo eyes located within the sensor. The sensor 'looks' to see if the film's edge is in between the two photo eyes. It does this by detecting if one photo eye senses the film's presence and the other does not.

The automatic film tracking sensor then sends feedback to the machine control. The machine actuates the tracking motor to move the film carriage in the needed direction to keep the film between the sensor's two photo eyes. On many of our newer tracking sensors, a yellow indicator light turns on to signify that the associated sensor detects the film.

How to set up automatic film tracking on a stick pack machine

CAUTION: Before performing a repair, be sure to follow your organization's Standard Operating Procedures (SOP) for safety, lockout/tag-out, and Personal Protection Equipment (PPE).  Do not perform work in the machine compartment of an energized and initialized machine. Do not bypass any safety switches or relays. Failure to use caution while working on the machine by not using adequate safety procedures could result in injury or death. Only authorized personnel should perform machine repairs. Viking Masek cannot foresee every instance where possible machine damage or an injury could occur. Work on the machine at your own risk.  If you need assistance, schedule a service visit by one of our authorized technicians

1. TO Center the film roll to the carriage

To properly set up the automatic film tracking sensor, you must first center the film roll to the film carriage. Centering the film to the carriage ensures that the carriage can move the needed distance to the right or the left to track the film consistently. Here's how:

  1. Measure both sides of the film roll to the edge of both sides of the carriage. 
  2. Move the film's position on the spindle until these two measurements are equal.

2. To set up the automatic film tracking sensor

Now that the film roll is centered, follow these steps to set up the automatic film tracking sensor:


1. On the HMI, touch the Film Tracking icon to bring up the Film Tracking menu (red circle).

2. Turn off Automatic Film Tracking (1).

3. Use the Manual Film Centering buttons (2) to move the carriage and film path to the needed location.

Expert tip #1: Center the carriage. To save time on initial setup, center the film carriage to the machine before running the film. If the film roll is centered to the carriage, centering the carriage to the machine will place the film path near your needed tracking position. To center the carriage:

  • 3a. Pick the same spot on both carriage sides and measure those sides to the corresponding spot on the machine frame.
  • 3b. Move the carriage with the manual film centering buttons on the HMI until the two measurements are equal.

4. When the carriage is in a good spot and the two outside film strips are at the appropriate width, adjust the sensor to set up automatic film tracking; to keep the film at the needed location.  To do this, manually adjust the sensor position so:  A. the film moves undistorted through the sensors film guide (3), and B. the sensor is positioned so one photo eye senses the film and one does not (4). Use the indicator lights on the sensor (5) as a reference for knowing when the eyes detect the film.

5. Turn Automatic Film Tracking On (1).  The carriage should adjust as needed to keep the film edge between the sensor's two photo eyes.

Expert tip #2: After the sensor is set up and is tracking the film, leave auto-tracking on and make adjustments to the sensor location to adjust the film path quickly. The method helps fine-tune the film track. When auto-tracking is on, the film will follow the sensor location.

Expert tip #3: On a stick pack machine, it is a handy practice to run the film strips of the two outside lanes off to the side while you run the machine to adjust the tracking. Run the strips to the side until you have moved the carriage into a position where the film strips for the two outside lanes become the correct width to make sticks. Run the film strips down the appropriate lane once the strips are the correct width and your tracking is set. This practice saves time; after all, you cannot really make good sticks until the film strips are the appropriate width for the stick lane.

Troubleshooting film tracking problems on your stick pack 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 stick pack machine maintenance videos

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

How to change the knife blades on a stock pack machine >>

How to set up the slitter blades on a stick pack machine >>

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 packing machine preventive maintenance planner for daily, weekly, monthly, and yearly recommended maintenance tasks:

Download VFFS machine maintenance planner