Erik,
I searched the posts that you have started and now understand what you are talking about.
I am curious how the ITB system solves the ink water balance. On the press, ink and water migrate together to form a positive emulsion. This needs to be in balance to produce optimum results. There is always a small amount of water in the ink train and when the press shuts down, the water begins to evaporate from the ink. When the press is started again, the first few sheets are generally darker because there is less water in the ink. How does the ITB stabilize this condition?
I must tell you, this is the first time I have heard of your system. I am open minded to new technology to improve anything we do. However, after reading some of your comments I feel your are disrespecting the industry you are targeting for your product.
Todd
OK, these are good question. The term Ink/Water balance is used for different things. For the operator, the term is used when he must adjust the ink and water due to their interrelationship. He might increase water, which in turn reduces print density, so he increases ink. He has to balance these inputs.
Sometimes the term is used for the condtions on the plate where there is enough water to keep the plate clean in the non image area but not too much and enough ink to print to the right density. Sometimes it is a term that is some how conected to the level of emulsification of the ink and water.
My interest is with the density control problem and therefore I am talking about the Ink/Water balance that the operator must deal with.
The problem is very simple and not complicated as most have been lead to believe. The density control problem has always been and will always be a mass (ink) flow problem. It is not a chemical problem. The ink water balancing problem that the operator sees is due to the interrelationship of ink and water in the press. Not in a chemical way but in a mechanical way. It has to do with the ink feed into the roller train by the ductor. When water is increased, some of this water moves up the roller train and reduces the amount of ink that gets fed into the roller train by the ductor. The operator then increases the ink key setting to restore the lost amount of ink feed due to the affect of the water had onreducing the ink feed.
It is at the ductor that the ink and water are interrelated in the feed rate of ink. The ITB breaks this interrelationship by forcing the ink from the ink fountain roller to the roller train in a way that is not affected by the amount of water. With the ITB, one can not wash out the print even if you set the water to max.
This breaks the ink water balance. That does not mean that one should run with lots of water and that it does not matter how much water one uses. When the interrelationship between ink feed and water feed is broken, then you set the ink feed for the density you want and set the water feed for the quality of print. Changing the water will not affect the ink feed and therefore the density.
A washed out print is not low in density because there is lots of water but because there is little ink being printed.
Conservation of Mass is not a theory. It is such a well established concept that it is considered a Principle.
The ink that goes out on the paper MUST equal the ink that goes into the roller train during steady state condition. This means that if you feed ink into the roller train consistently, it must come out consistently. If you run at one density level and adjust something and the density drops, you should ask the science oriented question. Where did the missing ink go? If you don't know, then you really don't understand the process.
When you start a press, the press is not in a steady state conditions but is at the start of a transient which will converge to the steady state value. If you have a positive ink feed which will feed ink independent of changes in water, temperature or press speed, and if you have an accurate presetting algorithm, your print will converge quickly to the target densities. No one has to adjust it. No closed loop required. Just calibration.
There are all kinds of other benefits with moving to positive ink feeds which are not possible with what exists now. The ITB is just one very simple and low cost way to do it. Breaking up the interrelated condition of ink and water feeds, is the most important problem to correct before the offset press can advance in a scientific way. In a consistent and predictable way. In a low cost way.
I hope that has given you some ideas.