It might be that the cross cutting blades are dulling, and not cutting cleanly through the web. Check the knives for sharpness or adjust for greater clash.
Improper curl correction is another possible cause for this problem. If the curl is not properly treated at the decurl section, then sheets with too much “up” curl will jam at the cutter. If this is the case, make the necessary adjustments to flatten the web appropriately.
If the sheeter has air washed doctor boards, apply more air to the after the knife doctor board. Compressed air passing along the doctor board surface creates a slight vacuum which helps peel the leading edge of the sheet off the revolver and directs it into the mouth of the delivery system.
If the problem continues, install an air pipe after the knife revolver. Direct the air onto the top of the sheet so that it will blow the sheet down onto the doctor board. The air source must have a valve to control the flow of air. Compressed air is preferable over a blower motor design.
