Web Press Troubleshooting Guide - Folder - Second Fold

Description:  The second fold refers to the fold that takes place when running double parallel or delta fold.  Some web press folders have an additional cylinder that makes this possible.  It typically consists of gripper fingers and and tucker blades.  The gripper fingers lift the copy off the second cylinder and the tucker blade pushes the copy into the jaw cylinder a second time before the copy is released.

Problem:  2nd cross-perf not timed with 2nd fold tucker blade. 
Description:  This is usually on the same cylinder that performs the perf for the first cross fold.  If not, then you simply don't have this option and your second fold will not be as precise.
Solution:  This is a trial and error process at first.  The distance between the first and second cross perf must be exact.  If it is slightly off, you will get occasional bad folds.  Time it perfectly.

Problem:  Cross-perf not aligned properly.
Description:  How this second cross perf hits, may vary depending on the running conditions.  Tension differences can vary as well, causing the perforation to be somewhat crooked. 
Solution:  Cock the cross-perf to the point where it will fold straight.  It may not be perfectly straight on the cylinder, but the result is what matters.

Problem:  Improper tucker blade height.
Description:  The delta or double parallel fold cylinder will have additional tucker blades to facilitate the last fold.  This height must be uniform side to side and with other tucker blades.
Solution:  Ensure that each side of the tucker blade as well as in comparison with others that it is the same.

Problem:  Broken movable jaw.
Solution:  Check carefully that the additional jaws and tucker blades responsible for the second fold are good and replace if necessary. 

Problem:  Jaw pads worn out.
Description:  Just as with the first fold, each movable and stationary jaw have parts that wear.  These will wear over time.
Solution:  Carefully inspect and replace if necessary.   

I can't find my problem.

Start Over :Web Press Troubleshooting Guide