Wild claims – drives me crazy

Ok, so maybe it isn’t a drive but a short putt. Still, you’ll see what I mean.

In my job I’m on the receiving end of a lot of calls and email regarding the industry, products and competitors. A lot of it is rumor, single-sourced tidbits coming from just about anywhere. Of course, it’s the whole of it all with a little analysis that brings the value, not the individual pieces, but I digress.

I get this call from one of our salespeople. He tells me that he’s heard from a customer that they saw a demonstration where one of our competitor’s closed-loop color control system brought color “in spec” (I use quotes because the specs in question are often very subjective) in FIFTY REVOLUTIONS. Very impressive, if it weren’t for the fact that this number has to be off by a factor of at least 10.

Now the purpose of a color control system on a printing press is to remove the need for an actual live human being to manipulate controls on the printing press to make the printed colors (which are produce via four process colors and half-tones) look the way the customer wants, and to do this as fast as possible. After all, every inch of paper that comes off the press with the colors wrong is waste, so reducing make-ready waste is a very big deal in all printing. Naturally, what the colors need to look like is entirely subjective, and is determined by a representative of the printer’s customer. Despite popular belief, printing presses can’t always reproduce every color faithfully, so there is some compromise and fiddling that must be done.

On a large, web fed offset printing press the color is controlled by controlling how much of each process color is fed into the system in each of many areas of the press’s width. This is done with widgets called ink keys, which move in and out to allow less or more ink onto a series of rollers. All of these rollers roll against each other, transferring ink, and smoothing it out until its really thin, and distributed across the width of the roller just so. There are a lot of these rollers – like 20 or more, and the ink is very thick, like tar. This entire mechanism is called an Ink System, and it’s like a bureaucracy: You just can’t get it to move faster than it wants to.

When you add all of this together, the unfortunate truth is that ya just can’t make the ink move that quickly. Depending on how things start out, and what levels of ink are already on the rollers, there are times when it can happen quickly but no controls manufacturer is stupid enough to sell that as the normal situation.

Now I’m not saying this competitor is run by charlatans, we know them to be quite competent but not crooked and there’s no evidence they made the claim. This is simply a misunderstanding. Printing presses are very complicated, depend on a lot of physics to run properly, and the control systems needed to make them run at their best combine the complexity of both.

That’s the problem – a customer misunderstands, and customers talk. Another customer hears from “one of his kind” that a certain product does this or that and they just latch on to it despite what any of the manufacturers say. This is what drives me crazy.

So, if you are a printer looking at buying this equipment, please lean on your vendors for education. We want to help you, and it’s not in our interest for you to learn anything but the truth.

5 thoughts on “Wild claims – drives me crazy

  1. Steve, you are quite correct about the misconception people have about how the press actually works with respect to colour (density) control. The problem is a bit more serious than what you described. You suggest that printer lean on the suppliers for education. This is a problem because even the suppliers do not understand the process.

    The good news is that the process is not as complicated as you suggest. There are rules for how things work and these rules are not so complicated. The problem has always been that there are several design faults in the press which interact with each other and this has resulted in the process not being consistent, predictable and understandable.

    The other good news is that potential solutions to the colour control problem on press does not require high cost solutions and they can be potentially applied to legacy presses.

    Normally people in the industry think of control as some form of feed back method, whether it be by the operator or by the expensive closed loop control systems. People don’t think in terms of having the process inherently consistent and then providing the proper preset conditions. This is possible and will result in having a press that will go directly to its preset density values, run consistently at those values and not require any ink adjustment form an operator or closed loop control system.

    The knowledge to do this is fairly well understood and is relatively inexpensive to apply. I have developed a new science to describe these problems and the potential solutions. For some reason, the industry has not been intersted in such fundamental solutions. Maybe it is the over skeptical nature of the group. Anyhow, I have added something below, which is a short blurb regarding my efforts.

    Regards,

    Erik Nikkanen
    President
    Fountech Inc.
    Toronto, Ontario, Canada
    *************************
    Information for print process engineers and technology developers.

    Fountech Inc. has developed a new science to describe the density control
    problem in offset presses in a rational and analytical way that engineers
    require to be able to make predictable performance improvements.

    This new science is presented in the course: “Colour (Density) Analysis of
    Offset Presses for Engineers”

    Also Fountech Inc. has a patented concept that corrects the generic press
    design fault that is the fundamental cause of ink/water balance and its
    related density variation problem. At this time, a press manufacturer in
    Europe is developing this technology (US Patent 6,857,366) and has stated
    that it works much better than what now exists.

    For print process engineers and technology developers who are interested in
    the potential of having consistency and predictability of density control
    in the offset lithographic process, please contact Fountech Inc. for more
    information on the course and the potential technologies.

    Erik Nikkanen
    President
    Fountech Inc.
    Toronto, Ontario
    Canada

    416 444 6655

    nikkanen@globalserve.net

    Fountech Inc. The New Science of Density Control

    Like

  2. Erik – thanks for your message.

    Your idea, if I understand it correctly, is to limit the amount of ink that can be returned to the fountain through the use of a blade that forces all excess ink off of the supply roller, basically creating a one-way door in the ink train.

    You mentioned a European press manufacturer in a comment on Tribute’s Drupa Views blog, and you mention another press manufacturer in your comment above. Can you tell us who this is? Is this technology in use at a real-world printing plant anywhere?

    Like

  3. Hi Steve. Yes, you basically have the idea. The return ink is required because some open ink fountains can not shut the flow of ink onto the ink fountain roller completely. Therefore some ink must be allowed to return to the fountain or else it will go to the roller train when none is required (a mess). If the ink key is set so that its output is exactly the amount of ink that the new blade meters back to the fountain, then that ink key position is the zero set position. Proper zero setting is critically important to predictabiltiy because it is the datum for the preset values. With a normal ductor, it is impossible to determine the zero set point accurately.

    This technology, which is called an Ink Transfer Blade or ITB, transforms the normal open ink fountain, with its inconsistent ink feed, into a constant displacement pump. The ink that goes to the roller train is then mathematically defined as: the ink metered by the ink key minus the constant ink metered by the ITB back to the ink fountain equals the amount of ink into the roller train.

    The ITB is static and only moves to come off the ink fountain roller when there is no requirement for ink feed, such as when one goes off impression, etc. The ink keys are operated in the usual fashion and therefore there is no new training required.

    Sorry, but I can not say who the press manufacturer is. It has taken about eight years to get a press manufacturer to test this concept. This particular manufacturer was first skeptical but then surprised at the result.

    This is not just about a particular technology. It is about how people understand the process. About vaid knowledge and how to take advantage of that knowledge to obtain competitive advantage. In this era of harsh competitive activity and continuous lack of consisitency and predictability, I have been shocked at how the industry has had so little interest in potential solutions for all these eight years. Companies would literally prefer to go bankrupkt than try something that was not proven.

    So I have to say that the ITB is not running in production at any location yet. That is not for lack of trying but it is just so very hard to get printers and press manufacturers to take any chances at all. When one sees printers or suppliers who have sales in the billions of dollars, not wanting to test something that might cost a few thousand and might correct a major problem, then you know there is something wrong in the culture.

    It is really tough and what I have found to my great disappointment is that the technical community is a major part of the problem. No spark there.

    Erik

    Like

  4. Hi Steve,

    In your original post, you commented on your doubt that the claim of getting to colour within 50 impressions was possible. I would agree if the control was by means of closed loop control. On the other hand, I do think that such a target is practical and will be seen with in a reasonable time.

    I was going through some of my old material which had press simulations based on positive ink feed on an existing press roller train design and also on a different roller train concept.

    The concept design had slightly better performance than the positive ink feed existing press design, but what was stricking at the time, was how much faster the response of the positive ink feed existing press design was compared to the actual press with conventional non positive ink feed.

    Some might say that the difference in performance was due to the comparison with a real press but that press had also been used for testing a positive ink feed device and those responses were plotted with an on line density measuring system. The actual response seemed to be inline with the simulation.

    So long ago, it was understood that ink feed was much more important than roller train design with respect to response of obtaining a target density.

    Some might say that the roller train does affect response and that is true. A larger roller train will tend to have a slower response than a smaller roller train but that is not the primary cause of slow response of getting to colour in real world situations.

    The main reason it takes a long time now for the press to get to colour is due to the difficulty of getting to and maintaining the right amount of ink storge on the rollers in the roller train. The density of the print is very directly related to the ink film on the form rollers, which is very directly related to the total ink stored in the press roller train.

    Now the average steady state density is ONLY related to the ink feed rate but the actual print density, at any moment, is related to the ink storage in the roller train.

    The basic problems is that non positive ink feeds have a great problem maintaining the proper ink storage amount on the roller train. Also presetting now is not accurate and so the starting point is wrong and that causes the ink storage to move away from where it should be. All the factors that now disturb the ink storage amount on the roller train, then requires efforts to recover and that takes a lot of paper.

    With proper presetting and positive ink feed, the storage can be maintained. If one is always printing at standard densities, then going from on job to another will be very fast.

    Press simulators have been around quite some time. Of course they never describe how real presses perform. The real goal is not to make press simulators perform like real presses but to make real presses perform in a mathematical way, like the simulators.

    This is coming.

    Erik

    Like

  5. Hi Steve,

    Obviously your reading skills are not so good. On our web-site we talk about automatic color REGISTER control, not automatic color DENSITY control. Please be more careful if you say something on the internet, especially when it is not correct. I am certainly pleased that your comments say more about yourself then about the skills of our company. In case you really would like to have statistical data on closed loop density control then please contact me and I will give you all info.

    Sincerely yours,
    Menno Jansen
    Chairman Q.I. Press Controls

    Like

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s