I get a nick or small tear at the lead edge of the sheet. How do I get rid of it?
There are a few things that can contribute to lead edge nicking:
- First, if the crease looks good except for the nick, move to a narrower female channel. When using the yellow rib, you can use female channels down to the blue-2 dot. When using the blue rib, you can go as narrow as the orange 3-dot.
- Second, try offsetting the pull out wheels so there is NO pressure on the wheels. Slide the upper wheels off to the side so they don't contact the lower wheels. Click Here to download a 1mb pdf illustrating the concept. You can also click here for a Bindery Success Blog article on problems with pull out wheels.
- Third, try using a thinner creasing rib. If you are using yellow, go to blue, and so on.
- Fourth, experiment with machine speed.
- Lastly, flip a handful of sheets and run a test batch. Sometimes an unfavorable curl will cause nicking. Flipping the sheet may minimize or eliminate the problem. If you suspect curl to be part of the problem, Click Here to download a pdf that shows a technique for minimizing curl on your folding machine.
I seem to be going through creasing ribs very fast. What am I doing wrong?
Here are a few items to check:
- Avoid using excessive pressure. Deeper is not necessarily better. You are looking for a smooth, lightly rounded bead on the inside of the creased sheet. If the bead is torn or excessively dimpled, back off the pressure or try another setting.
- Try a different crease setting. If for instance, you are using a light orange rib on a 10pt stock, it will wear faster than a blue or yellow rib.
- Be sure the female component is centered. If your device has fixed female (it has an allen screw to lock it in to place) then follow this procedure for centering the crease. A close look at the position of the rib in the channel also works! If your device has a self-centering female component, then be sure it moves freely on the shaft, and that it rotates, with light finger pressure. If it binds, clean the shafts thoroughly and if needed, have any burrs repaired.
The score is crooked on the sheet. How can I fix that?
First, check all the basics: side lay squareness, sheet register going in to fold roller #1, fold roller tension, deflector blades (no burrs or dings), fold roller cleanliness, etc.
If the problem persists, determine whether the problem is consistent or inconsistent. In other words, is every score in the same position or does it move around the sheet?
For inconsistent registration, refer to the first troubleshooting question above, regarding Lead Edge Nicking. The same issues can cause inconsistent registration.
For consistent registration, where every sheet is identical but just in the wrong position, try this solution. One side of the sheet is travelling too fast through the fold rollers. You can slow that side down by cocking a fold plate (with closed deflector) on the side that you want to slow down. Usually plate 3 or 4 is used. Unlock the fold plate that side, pull it out about 1/16" and re-lock. Repeat until score is straight. For severe problems, use two fold plates. The idea is illustrated here in this pdf on straightening out perfs on 16pp signatures. Different job, but same concept.
I keep getting nicks on my creasing ribs. (drawing at right) What causes this?
The most common is when the operator fails to open up the slitter shaft wide enough while changing female channels. As one component slides past the other, it nips the creasing rib. This can take a crescent-shaped nick out of the rib as shown in the drawing, right.
Next culprit is that the female component may not be centered correctly, and one edge of the female channel is rubbing against the rib. Here's a brief tutorial on centering the female channel. (Note: this is for fixed female components only! For self-centering devices, be sure the shafts are clean and free of burrs. See the question on premature creasing rib wear, above.)
Third, if you are running very heavy stocks (or multiple sheets) you may get a slitter shaft bounce if you have a double sheet. The self-centering female might have drifted sligthly out of position, or completely out of position, so that when the shafts close up, the rib hits metal.
How can I get a deeper score?
Contrary to popular wisdom, deeper is not necessarily better when it comes to creasing. Crease depth is one factor, but channel width is more significant. So try different crease settings first, before you spend too much time playing with crease depth. If however you are running a very dense sheet, or laminated sheets, the rubber creasing rib might not be dense enough to get sufficient depth. In those cases, we have a hard, nylon creasing rib available on select models of the Fast Fit and EZ-Fit Tri-Creasers.
I'm having trouble scoring a light text stock; is there anything I can do?
Although the Tri-Creaser is designed for stocks from around 5-6 pt (.005-.006") and heavier (around 100# text weight) we encourage you to try scoring on light stocks. Digital text stocks for example, respond extremely well to an orange rib/orange 1-dot crease combination. Offset litho text stocks, especially gloss coated, are a bit trickier when you get at or below 5 pt.
In such cases, your best bet is to use the bottom fold plates, with no pressure on the last fold roller. This technique is described in the Fast Fit Tri-Creaser tip sheets, which you can Download Here.
I'm not getting the results I used to get when I first got the Tri-Creaser. What can I do?
Something changed, whether it's paper, environment, crease setting, or any of dozens of factors. First, try the job with a fresh creasing rib. (If you're out, you can order them here online at http://store.technifoldusa.com/category-s/87.htm)
If that doesn't fix it, experiment with different crease settings. Papers, inks, humidity levels, moisture content and coatings can change and all affect creasing performance. An 80# Cover stock (or any stock) may differ from one you normally use from a different supplier, and could require a different crease setting.
I just bought the Tri-Creaser and can't get one of the components to slide on to the slitter shafts. What's the problem?
Normally this is a problem with a burr on the edge of a shaft. Repairing the burr should fix the problem.
Although rare, this can be a tolerance issue that happens primarily with the female components that use bearings. All of our products are manufactured to exacting tolerances. So when the perfect storm of larger slitter shaft OD + smaller bearing ID occurs, the fit is too tight for a finger-pressure installation. Simply give us a call at 973-383-7920 and we'll replace the part.