Not every cutting problem begins with the cover. Observe whether the symptom stays with the sheet, die, cylinder circumference or machine width to narrow the source.
Local incomplete cuts or burrs
Check cutting-rule sharpness and height, die-board flatness and deep grooves in the cover. If the problem moves with the die, the die is more likely involved. If it remains at one machine-width position, check pressure and parallelism.
Deep grooves repeated in one track
Confirm that cover rotation or indexing operates correctly. When contact remains in one circumferential track, wear concentrates even with a high-quality material.
One-sided or cross-machine wear
Inspect cylinder parallelism, bearings, left/right pressure and installed cover height. If a new set quickly develops uneven wear, stop compensating with pressure and find the mechanical cause.
Seam damage or crushed board
For seam damage, check circumference, thickness, locking geometry, direction and debris. For crushed board, also review pressure, board moisture, flute, creasing and die design.
Record the symptom position, then test die, cover and machine causes separately. Change one variable at a time.
