Why Does the Film Wrinkle?

Problem

The film runs clean at low speed. As speed rises, wrinkles appear — typically on one side, or just before the forming area — and some become visible in the finished seal. The effect may start after a film batch change or a reel-size change.

Possible Causes

1. Tension balance across the web is uneven at speed.
2. Rollers or the film path carry residue that disturbs the web.
3. Forming-area alignment forces the film to track off its natural path.
4. Film behavior at the current speed is beyond the qualified setup.
5. Reel size change altered the web entry geometry.

What to Check

• STEP 1Observe where wrinkles form.Watch the web from the reel to the forming area and note the first point where wrinkles appear — it localizes the responsible element.
• STEP 2Clean and inspect the film path.Remove residue from rollers and guides; look for nicks or deposits at the wrinkle location.
• STEP 3Re-verify forming setup.Compare forming-area settings with the changeover record for this product and film.
• STEP 4Test the speed threshold.Find the speed where wrinkles begin. A sharp threshold suggests a tension or resonance limit rather than contamination.
• STEP 5Confirm the film batch.Check that the film on the machine matches the specification the setup was qualified with.

Corrective Actions

• Restore even tension and confirm at production speed, not only at creep speed.
• Keep the film path on the daily cleaning checklist — most high-speed wrinkle cases start as contamination.
• Return forming-area settings to the recorded positions and re-qualify with sample packages.
• When a new film batch or reel size is involved, run a measured qualification run before production.