Why Is the Cutting Position Incorrect?

Problem

The cut point is visibly off-center on the end seal, shifts gradually during the run, or intermittently produces a short or long package. Knife marks may appear on the seal edge. The fault often follows a format changeover or a recipe change.

Possible Causes

1. Cut phasing was not re-set after a format changeover.
2. Product pitch and cut length parameters do not match the current recipe.
3. Registration input to the cutting motion is unstable.
4. Knife drive coupling or timing belt has backlash.
5. Worn cutting tool changes the effective cut moment.

What to Check

• STEP 1Confirm the active recipe.Check that the loaded recipe matches the product and film actually on the machine; compare cut length and pitch values.
• STEP 2Re-check cut phasing.Follow the phasing procedure in the machine manual at low speed and observe where the blade meets the seal.
• STEP 3Observe registration stability.Watch the registration indicator through several cycles; unstable input shows as intermittent offset rather than a constant one.
• STEP 4Inspect the knife drive.With the machine locked out per procedure, check couplings, timing belt tension and tool fixation for play.
• STEP 5Inspect the cutting tool.Check blade condition and fixation; a worn or loose tool shifts the effective cut position.

Corrective Actions

• Re-phase the cutting system per the machine manual and store the verified offset in the recipe.
• Correct recipe parameters and re-qualify with sample packs before releasing the line.
• If registration input is unstable, work through the registration checks before adjusting mechanics.
• Report persistent mechanical backlash to Path Pack support with photos and the machine serial number.