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Important Checklist Item for Your Scoring or Perforating Machines

[fa icon="calendar"] Fri, Nov 10, 2017 / by Technifold USA

Rotary scoring and perforating machines with direct feed systems are easy to use and widely available. This type of machine has no register table but instead moves the sheet directly mini auto feedfrom the feeder into the shafts. You’ll find manual-fed, friction-fed and air-fed designs from such manufacturers as Rosback, Rollem, Graphic Whizard, Count, Pierce as well our CreaseStream series (right) and its predecessor, the Speedcreaser.

While they each have different features and end uses, the direct-feed concept which they share means there are a few setup and operational techniques in common. Here are a few quick tips.

The biggest area of concern doesn’t have a thing to do with the machine itself. Before you ever go near the machine to set up your scoring or perforating job, take a look at a frequently overlooked item—how well the paper is cut.

Direct-feed machines have a lot of pluses. They’re low cost, easy to understand, simple to set up and operate. The down side is that the feeder must do double duty; it feeds the sheet and it registers the sheet. Each sheet MUST hit the scoring and perforating shafts precisely in the same position from one sheet to the next. Machines with register tables separate these two functions in order to give you a bit more control.

In order for the direct feeder to work well, each sheet of paper should be “square” and consistent in size from beginning to end. The term “square” really refers to the fact that all four corners are at perfect right angles. You can check this by folding a sheet over to see that the leading edge and tail edge are the same, and that both left and right sides are the same. If one or both dimensions are not exactly the same, your sheet is not square.

It’s the garbage-in-garbage-out rule. If your paper is sloppily cut, your registration will reflect it. You can adjust for a sheet being out of square as long as it’s the same throughout the entire run. It’s nearly impossible to keep up with paper that is inconsistently trimmed. On bindery equipment with register tables, a poorly trimmed job will at least have the benefit of good register relative to one side of the sheet. It gives you a bit more control than a direct feed machine in that you can compensate to some extent for trim variation.

But don’t be put off by this. It’s fairly easy to get a properly trimmed job from the guillotine. In fact, every job should be precisely trimmed. The problem is that it’s often overlooked, or the cutter operator is simply not mindful that precision needs to be built in to any job that’s headed to another piece of equipment.

If your guillotine cutter is in good working order, (as well as your operator!) a properly cut job will run smoothly and consistently all day long. If you are cutting several units from a bigger sheet, (for instance, 4 11x17’s, A, B, C and D, out of a 23x35 sheet) it might help to run one complete unit at a time rather than randomly loading from any unit. (Run all of A first, then B, etc.) Check your position and register at the beginning of each new unit. If there is any cutting variation, you’ll catch it and adjust accordingly.

Be sure the operator is familiar with the scoring or perforating machine. Sounds crazy to even say this, but we routinely run across bindery equipment operators without basic knowledge of their equipment. For instance, we asked one operator with a tech support issue if the slitter shafts had been set for the thickness of paper he was running. He said “Yes, they’re set correctly.”

After a little digging we discovered that he never knew that the slitter shaft gap on his MBO folder could be adjusted and fine tuned. He assumed they were “set” correctly at the factory, and that as long as he had the paper in the caliper, they need not be adjusted again. In an ideal world he would be right. But we all know that in precision work lots of adjustments are  made all the time.

Hey, you don’t know what you don’t know! So if you’re the owner or supervisor, please make sure your operators are trained. If you’re the operator, use your initiative to read the manual, to talk to mechanics and to learn from colleagues.

Keep the machine clean. A quick dusting or wipe-down at the end of each shift will do wonders for ease of set up!

If the score or perf does not register, check the infeed guides.

  • They might not be square to the shafts.
  • They might not be square to each other.
  • They might be too tight against the stock.
  • Check that the paper is consistently trimmed.

If the paper won’t feed or you get double sheets:

  • Check infeed guides as above
  • Check friction feed tires and/or rollers to be sure they’re adjusted properly.
  • Check that feed rollers are not glazed. If so, clean and rejuvenate according to the manufacturer’s directions. If they are worn out, replace them.
  • Be sure you don’t have too much stock piled in the feeder on automatic feed machines.

If the Perf or Score Line is Bowed (Curved)

  • Check any guide rollers (a.k.a. ‘pull out wheels’) on the machine shafts for even pressure. You can also try offsetting the upper guide rollers altogether so they’re not in contact with the lower rollers. Let the perf or score drive the sheet all by itself and see if this improves things. (See previous blog article for more on this subject.)
  • Check pressure on the feeder tires.
  • Check that burr rollers are square (if your machine is so equipped). Use them on both sides of the sheet for even drive pressure. Burr rollers are typically used to flatten the perf and can affect the travel of the sheet. If for instance, you have one perf towards one side of the sheet, be sure to use the other burr roller at an equal distance from the other side of the sheet, even if there is no perf there.

This is by no means a comprehensive scoring machine checklist, but it will help prevent or fix a lot of basic problems on a variety of equipment. 

Topics: Scoring Machines, Guillotine Cutter

Technifold USA

Written by Technifold USA

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