Tap water vs RO

[spigot]

slightly left field this suggestion but in the past i had poor and inconsistent results from tap water. It turned out to be a type of algae bacterial contamination growing in the pipes i was filling from. So definately look closely at the water you have.

 

[Robilious]

Ok, using RO water gives you a more consistent starting point for mixing fountain solution. Chlorine content, spring runoff, old pipes, and even local construction can introduce excess particulate in your water. This can throw off your conductivity measurement when mixing fountain solution. So, always check your starting point, or, original water conductivity before mixing fountain solution. If your fountain solution manufacturer recommends a conductivity for you, it will always be "above water".

Water is a "finite resource". There has always been the same amount of water on this planet. Never more, never less. The same water we drink today was consumed, and digested by Cavemen and Dinosaurs.

In oreder for water to exist, it requires a certain quantity of naturally occuring elements, including various minerals. Water will "seek out" these components. RO water, although lacking this mineral content, and being theoretically "Pure", can in fact be quite aggressive.

Fogra (Fogra Forschungsgesellschaft Druck e.V.) recommends adding a water re-hardening agent to many web fountain solutions, to ensure that various metal printing press components arent damaged by the RO water.

That said, fountain solution manufacturers will often make a fountain solution that is specifically formulated for RO water. RO fountain solution will contain the required minerals to ensure your press doesnt become a victim of pitted chromes, etc.

However, as your original inquiry was running with tap water "instead" of RO water, you could very well be experiencing particulate matter coming through your water pipes and causing spotting.

 

[otherthoughts]

Purposely resurrected

Purposely resurrected

Is this old thread similar enough to a recent "RO vs.Tap Water" thread that it merits the resurrection

And just to keep the discussion stimulating.....

Ok Eric, I'm on-board with all your reasoning, except for these two areas...

1. The premise used for many of your arguments, is that the ITB configuration somehow has a greater influence on the downstream ink train. In other words, why should the ITB configuration have any greater influence on the downstream portion of the ink train than a more conventional inking system does?
2. Regarding the press interval. I would argue that the first down ink's TAC has a stronger correlation with the press' speed and thereby the press' interval which determines the length of time that the paper's capillary force has to act and increase the effective TAC of the first down ink, with respect to the second down ink.

I fail to see how the ITB technology influences the paper's capillary force during the press interval and resultant TAC increases to a greater degree than a more conventional inking system does?
​

Best Regards
OtherThoughts

 

[Deleted member 16349]

I

1. The premise used for many of your arguments, is that the ITB configuration somehow has a greater influence on the downstream ink train. In other words, why should the ITB configuration have any greater influence on the downstream portion of the ink train than a more conventional inking system does?
2. Regarding the press interval. I would argue that the first down ink's TAC has a stronger correlation with the press' speed and thereby the press' interval which determines the length of time that the paper's capillary force has to act and increase the effective TAC of the first down ink, with respect to the second down ink.

I fail to see how the ITB technology influences the paper's capillary force during the press interval and resultant TAC increases to a greater degree than a more conventional inking system does?
​

Best Regards
OtherThoughts

Other Thoughts, yes this is an old thread. But OK, I will try to comment.

1. The ITB has more influence on the down stream portion of the roller train than conventional because it is positive ink feed. This is not an instantaneous influence but an average influence. On the other hand with a non positive ink feed as with the conventional system, the conditions can drift at the down stream parts of the roller train. What is being influenced is the mass flow of ink.


2. The second question is similar to the faulty view that is common even in the research areas of printing. It is the fault of linking the surface interaction of the ink and paper with the total ink transfer. Many of these studies of ink transfer are static or dynamic but without constant ink feed.

Yes, one can argue that there are properties of the ink and paper that initially affect ink transfer but after the printing process reaches a equilibrium or a steady state condition, the amount of ink transfer is directly related to the ink feed. At that time, it is not related to the interfacial properties of the ink and paper.

If the ink feed is inconsistent then the ink transfer will be inconsistent. If the ink feed is consistent, then the ink transfer, on average, will be consistent.

So no matter what the paper and ink properties are or the roller settings are (as long as they are in contact and transfer ink) the total ink transfer will equal the ink feed on average. The problem with conventional inkers is that changes in those conditions affect the ink on the roller train and this affect moves up to the ductor and then affect the ink transfer into the press and causes inconsistent ink feed.

With overprinting, if all the second down solid print goes on the first down print, then the ink transfer of the second down print is not affected by the changes in tack of the first down print. As I have said in an earlier post, if some print of the second down print is overprinting and some is printing directly on the paper, then there might be some small differences.

Those differences would be there for conventional too. The interesting thing about a positive ink feed is that there is the potential of doing something about where the second down ink goes. If the second down ink has more water added, the total volume of ink does not change but there may be an affect on how much ink is being wet trapped onto the first down ink. It would be interesting to see if this is a viable condition.

Conclusion.

I don't understand why an industry prefers a non consistent method of controlling an important variable than having a low cost consistent method. I don't know of any other industry that would view things that way.

Also I don't understand why there is so much effort in trying to find something wrong with a more consistent ink feed approach than there is in just having the concept tested by an independent third party to prove what's true.

I don't understand why an industry that claims it wants to be more scientific, does not want to think about these things. Right now the industry has no explanation why density changes on press that makes any sense.

It is understandable that people can be skeptical but that just means that there should be an interest to find what is true.

After 12 years of trying to explain this potential to the industry, I am getting kind of tired of having to repeat myself about something that should be quite obvious once it is described.

 

[otherthoughts]

My sincere apologies to you Erik,

It was not my intention to offend you. Only to stimulate the discussion.

To be honest here, I think that you always do an excellent job of responding and examining the questions you are presented with.

If I were to consider the overall effect of the queries I've submitted to you thus far. I would think that the overall result has been a positive with respect to the ITB configuration.

It is also my contention that these discussions inform us all, and that even our most recent, and seemingly lacking portions of the discussion, are decidedly a better alternative than it would be if there were no discussion at all.

Instead of interpreting my recent queries as lacking (though they were). Think about the possibility that they were the only questions I could produce that you hadn't addressed more directly already.

Don't let it get you down Man, I suspect that we might all agree that the ITB configuration should be superior to any Ink Ductor configurations, in theory. The only real point of contention here would be the stability and reliability of the ITB configuration versus the ink ductor's stability and reliability despite it's shortcomings. Put simply, would the ITB's parts and components wear out so quickly that it offsets all the advantages it provides? Or will it bear up to the industries expectations?

And just as you suggested, further testing of the concept in the field is needed in order to move forward in settling this argument.

In conclusion, if the ITB configuration is indeed superior overall, it will be born out in time. So If and when the ITB configuration is proven to be a superior technology, every manufacturer will eventually adopt it.

Until that time comes, I suspect that you will be called upon to answer some of the same old questions time and again. Perhaps you could take some solace in the fact, that you do that very well!

Best Regards
OtherThoughts

 

[Dan Roll]

If your tap water is soft (and Vancouver does have pretty soft water) there will not be a lot of difference between what goes into your RO unit and what comes out. You could test to see if your tap water is implicated in your problem by buying several gallons of distilled water to make fountain solution with and isolating one unit to see if the problem disappears.

 

[Deleted member 16349]

My sincere apologies to you Erik,

It was not my intention to offend you. Only to stimulate the discussion.

Other Thoughts, No need to apologies. I am not offended by your questions. I am just very tired of answering questions. I don't really want to debate these issues. I have always wanted to solve the problems that are in need of solving and moving the offset process forward.

It is not just about the ITB. That is only one way to solve a particular problem but there are numerous other problems that need to be solved but they can not be worked on properly unless the critical problem of consistent and predictable ink feed is solved. These are problems that need to be solved in order to make the process automated at a lower cost. It is about a new direction in the science of the process.

Time and money has been wasted by the industry following paths that do not lead to the results that were desired and from my perspective, it is obvious why. Why do all the major printers not have a sustainable competitive advantage? Why do all the press manufacturers not have a sustainable advantage either? It is because they don't do very much different.

The press manufacturers have delayed so long that now, manufacturers of digital presses have been able to put their foot in the doorway. If the offset press manufacturers would have developed presses based on some of the new science I have been developing maybe it would have been too difficult for the digital presses to get established. But no, the writing is now on the wall. For small production, digital presses might just push offset out. Let's face it, if most of the printers are small mom and pop operations maybe all they need is a good digital press.

This is an industry that all seem to die from the same desease of lack of innovation. It should be that the innovators beat the non innovators. At least that would be an interesting competition. All I have seen here is a situation where all starve and most are just waiting for a hand out from a growing economy which unfortunately will not come.

 

[janezl]

Let's go back to water issue: few days of continuous rainfall gave me question: can well filtered rain-water be used as a base of fountain solution?
Any experiences?

Janez

 

[Dan Roll]

Rain water is natures distilled water. It may pick up a tiny bit of contamination from the air, whatever it lands on, or what it is collected in, but will be well suited for fountain solution. If you believe those that say water must be of medium hardness for printing (They never explain why) you could add magnesium nitrate or some other water soluble hardening agent. If you store rain water you will have to protect it from bacteria growth, bleach works great for this...

 

[CD102]

Acid Rain

Acid Rain

Many parts of the nation have acid rain. Since the fountain solution will be an acid etch, I don't suppose it matters if the water is on the acid side to begin with. The problem is will you get a consistent supply of rainwater and whether the cost of capturing and storing that water is more expensive than generating RO water?