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Use Your Gatefold Plate to Prevent 3 Common Folding Machine Problems

Posted by Andre Palko on Fri, May 03, 2013

If you happen to have a gate fold attachment for your folding machine and you use it strictly for gate folds, you could be cheating yourself. You may not know this, but it’s entirely possible to use a gatefold plate to reduce, or even eliminate, three issues common to letter folds and other multi-panel folds:

  • Dog ears. These are the annoying bent corners that tend to appear on inside panels of multi-panel roll folds.
  • Curl. Multi-panel brochures on heavier cover stock have a tendency to curl on buckle folders, which in turn leads to other problems.
  • Scuffing. This often happens on inside panels where there is a full bleed. Again, heavier stocks are more prone to this.

letter foldThe normal procedure with a gatefold plate is to set it up for a specific job and then remove it when moving on to the next non-gate fold job. Reno Cyr Sr., a regular Bindery Success contributor and veteran lead folding machine operator with New England printer and Technifold client JS McCarthy, decided to see if he could skip this step when moving from a gate fold job to a 3-panel letter fold. If so, it would certainly save some precious make-ready time.

Using a Stahl SSP machine with a 6-plate folding unit, Cyr left the gatefold plate installed in #6 with the sensor in #5. (In a 4 plate machine, the gatefold attachment would be installed in #4.) The two folds were then made using #5 and #6. Lo and behold, Cyr discovered that it works extremely well and delivers unexpected additional benefits.

First, it practically eliminates the problems he has with dog ears (bent corners) on the inner panel. The action of the gatefold attachment is designed to keep the leading panel closed when it reaches the point of buckling. This in turn allows the gatefold to happen cleanly without the panel opening up and interfering with the folding process. But the action is the same whether it’s a gate fold or letter fold. By keeping the panel tucked in prior to buckling, you minimize the chance for a corner to bend backwards.

Second, when running a letter fold on heavy cover stocks, he is able to reduce the curl. This is done by inserting double the regular number of sheets in fold roller caliper #7 (or #5 in a 4-plate folder.) Without the gatefold attachment, doubling up the sheets to open up the last fold roller often leaves the sheet stuck in the final fold plate. There simply isn’t enough ‘drive’ on the tail end of the sheet to force the fold. The bulky lead edge panels tend to pop open and are anchored by friction inside the conventional fold plate.

With the gatefold attachment keeping the panel closed until the split second it is ready to fold, friction is reduced. Less force is required to move the sheet from the plate and the tucker mechanism might even give a little push of its own.

Third, it reduces scuffing. This sometimes occurs on jobs with full bleeds on the inside panel. When the final fold takes place, especially on a tight fold or on heavy stocks, the inside panel itself can scuff, or it can mark one of the other panels…or both. With the gatefold attachment the tucker mechanism keeps the panel closed at the moment of buckling. This removes the opportunity for scuffing to take place.

And of course you get the original benefit that Cyr was looking for: easier and faster make-ready time! Anyone who’s ever run a floor model folder will agree that bending over to remove and install the lower fold plates is no fun. And when that next gate fold job comes through, the plate is already installed, so you shorten your make-ready time (and save your back) once again.

Gate fold attachments are available for all popular floor-model folding machines such as Stahl, MBO, Baumfolder, Horizon and more. Granted, you’ll need to be experienced with the gatefold attachment to truly make this a time-saver. If you’re not experienced, this is a great down time project to work on learning and getting experience. It’s an effort that easily pays off by reducing the folding problems mentioned above and it’s one more piece of bindery ammo for your folding machine arsenal.

Thanks for the tip Reno! As always, please feel free to share your comments and experiences below.

Tags: Bindery How-To Tips, folding machines