Offset Press Troubleshooting: The Folder
There are some basic principles that can help you troubleshoot any problem on an offset printing press. The folder is a complicated beast, but here are the essentials:
1.Stop And Think!
Make adjustments that are logical. In other words, have a reason for making them. Too often, in the stress of it all, the pressman adjusts things that don’t make any sense. This in turn makes the problem worse.
- Know The Sweet Spot.
Every folder has numbers that generally work well. Know these numbers. Have them written down somewhere. Every pressman should have a little book of these numbers. They may not always work, but they are at least a reference point to start.
- Examine Closely Consecutive Signatures
It’s not rocket science. If you have a 2:5:5 folder for example, you can deduct which jaw or tucking blade is causing the problem. You can also examine if there is any pattern to the problem, every 5 or 6 and so on.
- Use Your Instruments
There are some essentials that every pressman should have that are essential to troubleshooting any part of a high speed offset press.
a.) A good flashlight – not a piece of junk. Something with a decent brightness. I recommend 900 lumens or more. Look on ebay.
b.) A strobe light. Again, something of good quality. One that will shine well into the folder or any other dark nook or cranny.
c.) Digital camera. Something used more often to see those sporadic problems. Set up a high frames per second cheap $100 digital camera up to film a part you suspect of giving you trouble and you can play it back frame by frame to troubleshoot.
- Check Adjacent Row
If you run a press that has two printing lines, does it occur on the other line? This is a dead giveaway as to where the problem is occurring in the folder.
- Examine The Signature Itself
The copy itself that is not right is telling you the story, you just have to interpret it. Take the time to think about it. This may be hard when the press is running full speed, but examining all the crease, fold marks, slipperiness, or tears, you can come up with logical reasons as to why your folder is misbehaving.
Good troubleshooting skills of course come with a thorough understanding of the folder and how it works. By applying some of the points above, you can successfully solve folder problems.by John Frolov