ad

Tips for Designing Your Inline Finishing System

The solutions to produce a finishing line can be varied and complex, but with careful planning you can optimize for the best design.

I've seen probably about 200 inline finishing systems and I can tell you that not one of them was the same. The solutions to produce a desired finished product are as varied as the products themselves.

I have been involved in designing and implementing these systems and I can tell you that you should not design a system without a professional representative from a post-press company.

To get you started, I've prepared a few guidelines that will help you understand a few limitations and advantages of the various components out there today. I'll by no means cover them all, but the basics are covered here. They consist of:
  • Conveyors - table and overhead
  • Flow and Bump turns
  • Trimmers
  • Compensating or Log Stacking
  • Palletizers
You may notice that these components generally occur after a press folder. Many presses include gluing and perfing systems that occur before a stream is produced off the press. Those components I'll reserve for another time. So here goes.

1. Conveyors

gammerler overhead conveyorThe above system shows an overhead conveyor system. Such systems present an advantage in that they help work around restrictions that the floor plan or equipment layout presents. However there are some factors that I have found are helpful when deciding whether to use this equipment.
  • lengthening the stream creates more expense for waste and equipment
  • copies, at least for this portion of the stream become inaccessible
  • repairs or jams can interrupt the printing process
Conveyors consisting of tables are much simpler. They are accessible to the pressman and provide room for taking samples or correcting flaws in the stream. Paddles can be installed on conveyors allowing more correction in the stream. But of course, I don't recommend adding these just for those reasons alone. Your line should be kept as short and efficient as possible.

#2 Flow And Bump Turns

These are used when switching orientation of the spine to an orientation that suits the next process in the line. I recommend that these should be kept to a minimum. The more of these you add (especially bump turns), the more unstable you make your line, thus causing more work for the press operator.

Flow turns are the most stable, but I recommend using them before any trimming takes place. Why? The looser a product becomes - in other words, the more edges you've trimmed - the more unstable it can become. The stream around a bump turn is stressed twice - once when turning and once when straightening out again. The looser the copies, the more room for error. If at all possible, I recommend reserving these turns to before the trimmers.

As for bump turns, the same applies to these. The less the better. They are far more unstable and prone to jams. If going to a trimmer afterward, I recommend putting a jogger immediately after that, perhaps even sensors and a dump gate that will dump copies that do not bump correctly. I'll say it again, keep these to a minimum.

To summarize, remember these points:
  1. Stream stability is lost more or less depending on the way a stream turns
  2. Turns must be kept to a minimum
  3. A dump gate or an extra jogger is recommended after a bump turn

video

3. Trimmers

Trimmers are self explanatory. This one below from Gammerler is capable of trimming all four sides of the product.

I would recommend that you have a proper product orientation exiting the last trimmer. When the product is trimmed, you'll want to send it straight to your compensating or log stacker. In my experience, spine first is ideal, but I've seen it every other way as well. Give a lot of thought to how you want the product to exit.



video

4. Compensating or Log Stacker

This is one of the more expensive parts of the finishing line and I don't recommend going cheap on it. I favor stackers that are German engineered (I'm not German by the way). The pressmen I've come in contact with over the years swear by it.

Here are some things to consider when deciding on which compensating stacker will work best for you:
  • Cycle time
  • Product thickness
  • Product entry
  • Finishing requirements
Let me explain. Cycle time is important and can be what effects the cost of the machinery you need. If you need to deliver small bundles from the stacker and you print a thick product, you will need a small cycle time inside the stacker. In other words, all of the stacker's functions must take place: gathering, counting, compressing, turning and strapping are all functions that can take place within the stacker for each bundle.

I recommend communicating with manufacturers exactly what you expect from the product as they can give you this information.

The product entry (usually spine first) is ideal, but even more important is your exit from the stacker. I have seen some setups where a product was strapped before exiting and this is an alternative. But in my experience, spine must come first since the loose pages on the bottom of the pile will catch in the delivery afterward.

5. Palletizing

This of course refers to stacking your printed product on a skid. I would also add, that if you choose robotic palletizing, get ready to pay. It's not cheap, but can cut down on labor and increase productivity. The systems that I have seen work very well and the controls require very little teaching.

Final Words

When deciding on a finishing system, do your best to come up with a plan of your own, even before speaking with a professional. Or at the very least, have clearly in mind what you want to accomplish on your finishing line. In many ways, a little creativity can present good solutions.

No comments:

Post a Comment