Problems on alcohol free press, ph rising ??

JOHNYPRINT

JOHNYPRINT

Well-known member
:confused:Hi all
I would like to ask a question going back to the alcohol free subject. Iam a machine mider in the UK operating ROLAND 710 5/5 perfector, installed brand new 12 months ago by man roland. We have a technotrans damp system and the machine is spec for alcohol/IPA free. we also have a betaF filtration system. We are not using a R/O unit for our fresh water inlet. We are currently using SUNLIT intense four colour process(sun chemical) piped to the units via technotrans ink pumps, the fount is stehlin +hostag substifix AF doused at4% to give a ph between 5-5.3ph, 11.5 centigrade, coductivity is at 2300.
PROBLEM= over the working week the ph rises,not continously but by the end of the week we could have a ph level of 7.0+, during the week we will drain off a couple of barrels if it gets to bad and at the end of the week we will have to flush out. we have obviously been talking to our ink supplier(sun chemical uk) about this issue and they have told us that we have a fungus problem and supplied us with a flush solution to to clean the system with,this only works temporarily, we think that maybe the problem originates from fillers coming out of the paper we run therefore making the ph more alkaline.
Could i have some feedback from people who have had experience or may have knowledge of our problem with some constuctive reply as to deal with this issue. The machine runs 24hours 5 days a week. all experienced minders but none of us has run alcohol/IPA free previous, could it be that the IPA kills the bacterial/fungal problems ???.
 
if your not opposed to the additional cost you could set up your technotrans to "auto dump." The autodump feature will without any intervention drain off fountain solution when conductivity deviates from a preset value and replenish with fresh to keep things in a much narrower operating window.
In addition i have to say that im amazed at how much more consistency you can get when running reverse osmosis water. We will typically run for 2 shifts all week long WITHOUT auto dump and usually keep conductivity within 400 of its starting point of 1000. By starting off with 0 conductivity, as a result of ro water we can dose to app 1000 with our doser set up for only 3% utilizing a one step solution. If it werent for that control offered by ro water we would be looking into setting up our technotrans to auto dump.
 
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Hello,

As you have said, the most likely cause of your pH drift is contamination of the fountain solution from the paper and/or ink.
It is possible that the fount is pulling extra paper coating from the paper or over emulsifying the inks
IPA does have disinfectant properties, but modern fount solutions should contain anti-fungus as well as calcium inhibitors etc., so the lack of IPA should not be the cause for this.

One thing to check before you start changing products around, is that your doser is working correctly; as if it's not maintaining the correct amount of fount over time, this would cause this pH drift.
Assuming everything is ok with the doser, there are a few things I would suggest:

1) Get a decent system flush (ABC Allied A+B Systems Cleaner)
The single flush solutions are laborious and ineffective unless you have hours to spend doing multiple tank dumps.
The systems cleaner from ABC Allied is far more effective due to the two-part (alkali/acid) system and elimination of the need for multiple tank dumps.

2) Use a simple filtration system (We recommend this for all of our IPA Free customers)
This will extend the life cycle of your fount solution by keeping contaminants at bay for longer

3) Remove calcium and other deposits from the rollers

4) Use a more suitable fount solution (ABC Allied Titan Elite Fount)
Make sure that the fount solution has the desired pH (you may need to aim for a lower pH) and contains anti-fungus additives as well as calcium inhibitors as standard.

If you need any more pointers or literature on the subject, just let me know.
There's absolutely no reason you shouldn't be able to run alcohol free on this press with the right products.
 
Change your fountain solution to a different supplier!
We once had this issue with another suppliers fount & they blamed everything bar their product. Saying its the paper, the left over residue on the plates blah blah blah.

Changed to a different fount and the problem went away
 
Alois ,your pdf does not really shed any light on this topic/thread. If you have a problem with LukeW please do it away from this thread. You have hijacked my threads before and you have very little professional input to contribute! Please stay away from my threads. Thanks johnyprint
 
mmmmm

mmmmm

Johnprint and not forgetting "inky"


Oh dear! It would seem I've ruffled you feathers - again

Salient Points: 1) the threads/topics are open to anyone who wishes to give

an opinion or answer. 2) You might have "lots of Heidelberg experience" but in my humble opinion

-- not much knowledge of Lithography.


Lastly, regarding my "very little professional input contributions" - I'll leave that for others to decide.


Regards, Alois
 
I thought I responded to this thread earlier, but don't see my post so I will try again.

A fungus infestation bad enough to effect the pH of a buffered fountain solution would be visible as a gloppy, snotty mass with a vague yeasty smell. In the absence of this, it is not likely you have a fungus infestation. Fungus organisms would not preferentially eat the acid portion of the fountain solutions' buffer system, they would not be on my suspect list for a pH drift.

Raising the pH of a buffered solution requires alkaline chemistry and a fair amount of it. Paper could be the cause, but it is more likely a plate cleaner (some are millions of times less acid than the fountain solution) or your plate finisher. Many modern plate finishers are quite alkaline and you would be surprised how quickly a continuous dampening press can contaminate the fountain solution with plate finisher. It is especially troublesome for printers who do short runs or have large format presses, and a bigger problem for printers who have both. Many plate finishers contain other ingredients in addition to their alkalinity which cause serious problems for the fountain solution. I would test the pH of the finisher and any other chemistry that might find its way into the fountain solution. Anything above a pH of 9 or so would be immediately suspect.
 
I have had the same issue in the past. It is mostly stock related causing the fountain solution to contaminated. Uncoated offset bond is the worst. May ph was buffered at 4.2 and would rise to over 6 after running about 200 m impressions which was about 2 days worth of work on one shift. It would cause loss of control on ink water balance and cause drying issues. I switched to new fountain solution and it was like night and day difference. I still had to dump tanks every two weeks to keep things clean and running great. Roller maintenance is also very important as lower grades of stock will cause problems when running alcohol free. Find the right fountain solution and it should help.

Hope you work it out.
 
Alios, the point I was trying to make is a good fount these days will have high quality buffers in them and there should be very little PH drift.
If you have been running for years with no PH drift issues & you then change to a fount that it occurs with alarm bells go off especially if you switch founts and the issue is immediately fixed.
In our case and possibly Johnprints case the buffers in the fount are breaking down. (This is if nothing but the fount has been altered)
 
What can I say ?

What can I say ?

Gentlemen,

A PDF from a "very little professional input contributor"


Regards, Alois
 

Attachments

  • Gentlemen and fellow Lithographers # 2.pdf
    28.5 KB · Views: 199
Some fountain solutions certainly buffer better than others. SubstiFix AF is made by H-S who make CombiFix, a product that buffers very well. It may be in order to accommodate the alcohol replacement ingredients they have reduced the size of their buffer system or have changed the type of system they use, I have not had a chance to run a buffer titration to evaluate this product (you don't see many European fountain solutions on my side of the pond).
Printers who see these pH drift issues with paper tend to be web printers who expose their fountain solution to more paper in a day than many sheetfed printers use in a month. Typically, the alkaline material usually found in paper is not particularly water soluble (alkaline materials will not raise your pH unless they are soluablized in the process) so a rapid interaction with the fountain solution buffer system might be unlikely.
You might try mixing up some fresh fountain solution, putting it into some little bottles and placing some of the things you suspect into them for a brief time and then measuring for pH drift. This should lead you to the culprit right away.
 
You all should lighten up on Mr. Senefelder, his library is vast and he always seems to be trying to help. I get flamed all the time for advice people do not agree with, but without being on-site, it is difficult to identify or solve problems and one cannot always be right (except for my my girlfriend, who is never wrong, but she will take no interest in anyone's printing problems).
 
I disagree dan. I come on this site to get professional answers ,not to read about alois having a dig at lukew, as i said keep the crap away from my threads . as for a vast library , thats called the internet, my kids can copy and paste. no keyboard warriors please, just informed opinion .regards john
 
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We are about to go to stellin and hostag ink, we are already using their fount. Once we have their ink and chemistry on press we will take it from there. We are 90% there but it helps to listen to other opinions. regards john
 
Hi Johny,

Are you using an Alkaline roller rinse (calcium remover) on a regular basis? We've been alcohol free for over 15 years and that was the only real change in habits we had to make.
 
JOHNYPRINT said:
We are about to go to stellin and hostag ink, we are already using their fount. Once we have their ink and chemistry on press we will take it from there. We are 90% there but it helps to listen to other opinions. regards john
Click to expand...

Stehlin do some excellent ink sets, we find the most popular to be Resista, which is also suitable for perfecting, as you are.
I'm not sure this will fix the pH drift issue though; as commented by many above, it sounds like you need to try a different fount as it may be aggressively removing bits from the paper causing contaminants.
We find the combination of Stehlin Ink (Resista) and ABC Allied Fount (Titan Elite) works very well for our UK customers.
 
I agree that getting in a trial fountain solution would probably be one of the first things I try. Since you already have the new inks on the way, looks like you're already committed to that for the time being. If I see a similar problem nowadays, I wont think twice about getting a few gallons of trial solution in. Usually it wont cost you much, if any more, than you are already paying and you wont be fighting against yourself trying a bunch of different things if there is a serious compatibility issue.
 
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