Why Is the Film Tracking Incorrect?

Problem

The operator sees the film edge slowly moving toward one side of the film path. The seam loses its centered position, one edge of the wrap appears stretched while the other wrinkles, and after a period of drift the machine may stop on a film-break fault.

Possible Causes

1. Film roll is not correctly centered.
2. Film tension is inconsistent.
3. Film path is misaligned.
4. Tracking sensor is dirty.
5. Tracking parameters require adjustment.

What to Check

• STEP 1Check the film roll position.Confirm the reel is seated square on the shaft and the core clamp is tight; verify the roll is centered against the machine's reference mark.
• STEP 2Inspect film tension.Compare tension behavior against the values defined in your machine manual; look for jerky or pulsing movement of the web.
• STEP 3Check the film path.Walk the web from reel to forming area: every roller and idler should be square to the frame and free of film residue buildup.
• STEP 4Clean the tracking sensor.Power down per your lockout procedure and clean the sensor window with a lint-free cloth and a cleaning agent approved in the machine manual.
• STEP 5Check the tracking response at low speed.Run at reduced speed and observe the correction behavior before returning to production speed.

Corrective Actions

• Re-center the film roll and lock the core; mark the verified position for future roll changes.
• Re-establish consistent tension per the machine manual and re-check after each reel change.
• Realign any roller found out of square; record the correction in the shift log.
• Clean the tracking sensor and add it to the daily cleaning checklist.
• Adjust tracking parameters at low speed, then confirm stability at production speed before releasing the line.