Fuji LHP-J plate blinding problem

[amccolor]

Hi all,

We are having plate blinding problems on our Fuji LHP-J plates in the last month or so. We run 2 Komori 40 presses and we use Liberty 1-step fountain solution from Sunchemical. We have been using the same drum of fountain solution for months, and the problem just started. We have been using Fuji plate user for almost a decade. We have never encountered this issue before.

We tried using some Fuji plate cleaner/gum and are unable to bring the plates back to life. We are having to re-image plates on our Lotem Quantum. The plates are lasting between 7m to 25m impressions, and we typically have problems on black, magenta, and then cyan.

Fuji is pointing towards the fountain solution as the culprit, and the supplier for fountain solution vendor (Sunchemical) is pointing towards (take a wild guess).. the Fuji plates. Sunchemical is alleging that they have heard of other users out there having the same blinding problems with Fuji plates.

Fuji is sending some service guys in on Monday to help us diagnose the problem, and I have a feeling they are going to ask us to try their Anchor fountain solution.

Anybody have experiences / solutions to share?

Thanks in advance,

Anton

 

[TheProcessIStheproduct]

yeeeep, fuji plates do like to blind, you can really attack calcium on press and it may get better, but we wasted a ton of time chasing our tail around trying anchor subs, stand on one foot, must be the paper, blaa blaa blaa, I have been at this a long time and changing fountain solution has never helped a press problem, but the plate guys love to point to the chemistry, but everytime I have had a problem it was always plates or ink...never chemistry! I am sick of the fingerpointing!!!

 

[turbotom1052]

i too would be looking at calcium as a possible cause. There are many threads on this forum regarding calcium buildups in the rollers causing blinding and stripping problems on press. There are also many suggestions on how to get rid of calcium buildups.

 

[Asures]

Anton,

1st - Stocks: Papers these days are recycled and rarely printers use a virgin sheet. The calcium carbonate that is in the stock both as brighteners and fillers in the sheet are accumulating within your water form roller and or your ink form rollers. This eventually affects the transfer and take off of the ink on the plate surface by causing the image to become "Hydrophilic" (water loving) and not "Oleophilic" (oil loving).

Though you might have been buying the same house stock regularly, it doesn't mean that the batches are the same. Some might be more Alkaline than others and if you have been running non-stop without applying a proper decalcifying maintenance, this could contribute to the problem.

*This same calcium will accumulate as well in the pores of your blanket and eventually transfer back to the plate and migrate to the forms.

2nd Finishing Gums: In many instances where I have seen the blinding occur on those plates when either aged gum or an excess amount of gum is applied to the plate as finisher. This usually shows up when you pull up initially as either gum streaks or hot spots on the plate. I have also seen it not show up until after a few thousand impressions as well. Try taking the plate once developed and applying straight Asphaltum Storage Gum to it and buffing it down by hand before hanging it and running. See if that helps by removing any lingering finish gums that are not able to be removed from making your first pull on press.

3rd Water Pick Up of the Inks: If the Liberty one-step fountain solution that you are using is running too wet, it will draw calcium from the paper into the inks. Your inks have water fighting varnishes in them but based on the package and manufacturer, some are less forgiving than others. This calcium will inbed itself within the ink and may inhibit the plate surface from being able to distinguish image area from non-image. Rycoline fountain solution typically run excessively wet as their niche was and has been heatset web fountain solutions which require such.

If not mistaken, you still print Stochastic. This small dot and great non image area can allow for bizarre behavior to occur in the above listed problems.

I sent my contact info to your personal e-mail if I can be of help.

 

[Kurt Wiggins]

The Search of Happiness

The Search of Happiness

All,


At Heidelberg, we have a interesting resolution to finger pointing and the old blame game. Please take a look at our new video:

YouTube - ‪Heidelguy's Channel‬‏

If I can help in your search of happiness, please contact me directly.

Kurt Wiggins
Product Manager
Press & Post Press Consumables

Heidelberg USA, Inc.
1000 Gutenberg Drive
Kennesaw, GA 30144
Phone: 1 770 419 6894
Fax: 1 866 220 8418
E-Mail: [email protected]

 

[zoran]

Something is changed for sure as we have noticed in last month or so similar thing.
We have the same problem on three different presses, with different inks (one press is UV inks), with different fountain solution and the only thing that is in common would be plates so that is where we are investigating at the moment.
We use Fuji LhPJ plates too.
Of course, Fuji told us nobody else is complaining.
I think this is the strength of user forum where everybody can pitch in and get little bit more realistic version of the story.

 

[John Arneson]

We are also running Fuji LHP-J plates and are having problems on two different presses both run different inks and fountain solution. I think we have a different problem than yours though. Our plates will show a faint image on the plate outside of the sheet size at about 30 to 50 thousand, it will continue to get worse the longer we run. We may be able to get up to 90 or 100 thousand and have to replate.
Fuji has come in and told us it is a fountain solution problem. They have given me a two step Anchor product to test witch I am doing now with some good results.
Now get this, I mistakenly used the fountain solution as a one step. ( the solution they sent was intended for the other press that runs alcohol) but it worked on a run of 276,000.
It ran like crap but but the plates held the entire run. Keep in mind I had only put it in two of the five units I was running.
Fuji returns tell what I did wrong last week, started me with an alcohol sub. I ran one job of 30,00 and when I was done looked at the plates and the black and cyan plates were showing faint tinting outside of the paper size.
The work flow is nil right now so it may be a while before I can do any more testing.

 

[Rick@IPCO]

Since we use the Fuji LHPJ plates, and we experienced a problem that was characterized as "plate blinding", here is some info that may be of some interest:
1. The problem manifested as image areas that would fade or cease to print after a certain number of impressions (anywhere from 3,000 to 6,000 sheets).
2. The problem always occurred in areas of the plate that had light coverage (low screen percentage) for that particular color. The problem would NOT show up in areas of the plate where that particular color was a high dot percentage or a solid.
3. The problem always occurred in the first few units the press sheets went through. If the Black and Cyan, plates had areas of low screen value coverage, that's where the image would start to go away, in the first two units.
4. The problem seemed to occur more on the outside left and right sides of the sheet.
5. When examining the plates, the dots were intact.
6. If the press blankets were cleaned well when the image degradation was first noticed, the image came back.
7. This issue only shows up when we run one particular stock. We are a shop that uses many different stocks and ink sets.
For over a day our pressroom was populated with reps from; our ink company, the stock manufacturer, our plate company (Fuji), Heidelberg, and our coating company. To their credit, nobody was really pointing fingers and everyone was really trying to track down the problem. The result? Well, the plates are not the issue; we run other long-run jobs on other stocks without issues, and the fact that the image comes back after washing the blankets pretty much closes the book there. I know some people are pointing to the fact that a common denominator between shops experiencing this problem seems to be the LHPJ plates. But could this just be because it's a really popular plate and a lot of shops use it? The (fairly vague) conclusion was that the recent changes in the stock manufacturing process (more calcium carbonate) and/or powder buildup (towards the outside of the sheet) were the likely culprits. The solution? Not a very good one since the stock manufacturing process is not going to change; keep doing what we're doing. Wash the blankets every so many thousand sheets.

 

[TheProcessIStheproduct]

I tend to think it is specific to the plates, I very rarely have seen blinding on short to medium runs and it has always been a fuji plate, the PRO-T would blind in a couple hundred sheets with some papers. Maybe it has to do with the capping layer they put on their plates???

 

[zoran]

Another bit of info I have that might help ring a bell is that plate opens up fine when they start the job, but if they go for lunch break and come back, plate will not open any more and it shows a lot on Magenta so they need new plate.
This is one of the new things that started happening recently and almost always shows up on magenta.

 

[chevalier]

Has anyone confirmed that there hasn't been some kind of EPA regulation change that the fountain solution vendors have silently changed their formulas to remove some kind of new banned substance? I recall this happening a while back and everybody was going mad pulling at straws only to find out that all of the vendors had made a change as required by law but didn't bother to tell anyone.

We use LHPJ plates with Boettcher fountain solution and have quite a high volume of plates always medium-to-long runs and have not had any issues. It could be that we either haven't gone through our inventory and used newer plates or newer fountain solution. We order both at least once a month.

 

[John Arneson]

Chevalier,
How long are your runs?

 

[chevalier]

I work for a packaging company. We mainly print only on SBS board but also some CCNB and recycled as well. The rare small run for us is ~5000 sheets and our typical run is somewhere between 20k - 100k sheets. At least once a month we have multiple runs longer runs longer than 250k sheets as well. We do have issues time to time with certain metallic inks eating image off of the plates but we have never had blinding issues like those mentioned.

Other notes:
We only use distilled water in our plate processor chemistry (except for cleaning) and are pretty manic about maintaining our plating equipment. As far as the press guys they pretty much use water from the tap and we are also located in a region in the US with insane amounts of of calcium in the water and near absolutely zero iron in it.