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Web Press Troubleshooting Guide - Cross Fold Tears

Definition:  This refers to the first fold across the grain of the paper in a web offset press folder.  Generally, the cross fold area refers to the area where the cutting and tucking cylinder meet the jaw cylinder.  Tears can happen in this area for various reasons.


Problem:  Tears are happening at the lead edge after the first cross fold.
Description:  While these tears happen most often at the chopper table, the transfer processes between fold cylinders and various belts can cause this problem.
Solution:  Inspect all belts for tears or imperfections.  Next inspect all tucker blades and jaws that they are not broken.  Inspect all foam supports that may be built into the tucker blade and jaw cylinder that they are not worn.  


Problem:  Tears are happening at the tail edge of the product after the frist cross fold.
Description:  Tears at the tail edge usually indicate that there is a control issue among the belts.  
Solution:  Move the position of the former and chopper table together to try the product at different positions in the folder.


Problem:  Pin holes are elongated.
Description:  As the copy gets cut at the cutting cylinder, it is grabbed by the pins (unless of course you have a pin-less folder).  This is a tension issue, but also could be a timing issue with the pins.
Solution:   Advance the nearest nip to your cutting cylinder to feed the paper faster into the folder.  Also, ensure your timing of the pins is set properly on the cam follower.


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