Azura TS

[TF019]

Hello All,

We have a Screen 8600 and are running the new Azura TS plates, we have been humming along no problem for close to a year and have been very happy with consistent dot on the plate with excellent color results in the press room. We had to slow down our drum speed which was a bummer but the end result has been a happier press room.

This week we are watching our dot and solid areas breakup prematurely on the press sheet when plates are on press (yes the emulsion is gone on the plate as well), primarily with the cyan and black units (yellow and magenta seem to hold solids and dots shape). Jobs we ran before with the same plate, same drum speed and same dot size (i measured dot size on new plate to original install plate which I saved) jobs are now coming out with different color.

I would have to state that somehow the emulsion is different on this lot of plates, Agfa suggested slowing down our drum speed to harden the dot but we can not take more of a performance hit on our PTR, so that's not going to happen as we are 550rpm now.

I've read past posts about similar issues with the Azura TS plate but nothing quite like this. Seems something on the press is breaking down the dots on plate.

Anyone have a suggestion that I can have press man check on the Komori 40" 4C Lithrone?

I would like to point my finger at this lot of plates (We are picking up a different box lot number today) but have no knowledge of the press. So press input would be appreciated.

Thanks in advance.

 

[Lukas Engqvist]

Documentation is important if you want to make claims… but before just thinking the plate is wrong, is there any special circumstances with your job?
What ink order do you have is Cyan first? Could it be you have a new batch of ink, that has a too high tac? Are you running a new kind of paper? Does it happen when the press is cold, or irrespective of cold or warm. Did you just change blankets? Do you have documentation to show that the ONLY difference in the problem run is the plate batch? We have once had a bad batch of plates, but since we had more plates in stock we could quickly document that it was the batch that was bad.

If you can document ALL the circumstances for good runs and bad runs it is very clear when isolating a problem. Provided you have the right documentation I think you will find the AGFA sales/tech people will set you straight.

 

[TF019]

Azura TS

Lukas, thank you for your prompt reply.

We have been running our ink order KCMY on the Komori since our original install 6 years ago and have never changed unit order for KCMY printing. We have been running the same cmyk inks from the same lot for the last 2 weeks. WIth the area in question of TAC, this was only 100C 67M 0Y 23K so total TAC is only 190, I've seen them run up to 380 before with the coater on so the pressman and press are quite capable of handling heavy coverage. The breakdown problem we are seeing occurs when the press running at 12000/hr so I'd say the press is not in a cold condition although it is quite cold outside here for us humans.

We are waiting for the new lot of plate to come in today and will try this first. I just talked with pressman and I guess when this current run is done they are going to switch the magenta and cyan units out, so we will try to change ink order, hopefully this will tell us if there is a problem within the first unit on the press.

I don't want to point my finger at the plates as we really like the Azura TS plates as they have made prepress's job much easier.

I will let you know results of new plate lot and unit change.

Before I went to lunch I imaged a new cyan plate to keep them running, it only lasted a few thousand impressions but they just went with it, they are now backing it up but as there is not a solid Cyan area we don't see the problem.

Should know more later today.

 

[SteveAgfa]

TF109

I sent you a PM.

Have you called 1-800-TRY-AGFA?

I'm not tech support - but it sounds like your optics might be dirty.

Regards,

 

[Lukas Engqvist]

You say you are running 100%C and it is just the cyan plate. Maybe I used the wrong expression what I was referring to is not total ink, but the "stickyness" of the ink. If you have 100%C and the ink is too sticky could be a problem. Now if the plate is not exposed enough you can even try after the cleaner heat the plate with a blow drier or something to bake the plate and see if it helps. (If it does then maybe you have dirt in your laser or focus is in wrong place etc. What is the working environment of your CTP? Is is dustfree, stable temperature and stable humidity? Is it first or last plate in package, are plates stored correctly? Are plates stored long before printing?)

Also, just to rule it out, and because it is an easy test you can try replacing the paper stock and run a couple hundred…*if the problem goes away it may be your paper manufacturer. This is why I say you really need to document well.

Hope you find a resolution to the problem quick.

 

[TF019]

Azura TS

I discussed the TAC issue with the pressman before he left and he stated all was normal the inks, he hasn't changed a thing and it's the same ink we have been running for the last two weeks when we didn't have this issue.

The problem has occurred now on two different types of stock, coated and uncoated.
The pressman showed me a used plate where a repeated image screen tint of 10% cyan basically wore off from right to left across the plate. I read the dot and it ranged from 7% to 4% in those areas, you could see the change visually across the plate. Seems to be wearing down quickly, more so on certain areas of the plate. A plate coming out of the wash measures within .5% across the width of a plate, before it hits the press. Something is occurring with the dot on the plate when it hits the press.

Our last full PM was in Oct 2010, I also suspected the lense so I got in there and cleaned with 91% Isopropyl alcohol and didn't see much on the cleaning tissue. I've cleaned it before when we ran plates that used scrubs as a critical part of the process and have seen what a dirty lense looks like. I will rule that out, focus test may be better question, which I will look at tomorrow.

Steve, I contacted Agfa support yesterday and they suggested that not enough energy was getting to the plate, slow drum speed down. We can't handle more of a performance hit with our PTR.

Pressman are getting ready to hang the new lot plates, I will let you know results.

I appreciate all of your comments, thank you

 

[SteveAgfa]

TF:

If they are suggesting that not enough energy is getting to the plate,
have you asked yourself what has changed over the year? If the optics
window has gotten dirty over the year, then that would be a cause of
not enough energy getting to the plate.

Azura looks properly exposed, even when under-fused.

As I say, it's a set-it, and forget-it plate; but Vlad properly pointed
out that you still need to make sure your engine goes through regular PM.

Regards,

 

[NJservice]

TF019,
Are you in Brooklyn, according to your profile?
I just passed through Brooklyn today!
I service Screen and Creo machines in NY, Jersey, Pa area and could have helped you figure your problem out. Darn it!

 

[buckeye]

Wouldn't all of the plates be problematic if it was dirty optics and not just the cyan and black? Changing units on press, just as a test, would eliminate a fairly large variable would it not?

 

[TF019]

Azura TS

NJservice, sorry but we are not in Brooklyn New York, located in Minnesota. Team EPS did a full PM back in Mid November 2010 after the election on our PTR, I checked my service records to confirm and I stated early in this correspondence that PM was done in October 2010, that was incorrect. So it's only been 3.5 months since last full PM.

Buckeye, my thoughts exactly, if the optics were out then we would have problems with all the plates.
The unit changed proved this point, read on...

A laser IOP test on the PTR showed all diodes running normal.

Last nights press run seemed to go well, the back side of these forms did not have a solid cyan box in the work as the front. I inspected the color bar cyan square and it did not break down any where. Reports from the pressman were "no problems".

This appears to be a press issue with how the 2 different units are handling the TAC of the ink.
If any one can put some input on this it would be appreciated as I never know when I'm being BS by the pressman as I don't speak the pressman language.

Thanks to all for your input, in my opinion the Azura TS 30 plates rock.

 

[Hessel]

This sound like the same problems we have with our Agfa VCF plate on web offset (newspaper). We have 2 presses and the problems occure on the new press. Sometimes after 10.000 copies the image wears the same like TF019 discribes. In what way will the ink container temp affect the TAC of the ink?

 

[Alois Senefelder]

Accurate

Accurate

Gentlemen,

1) The initials TAC stand for Total Area Coverage not the TACK of printing ink.

2) The tack of printing ink will not remove image areas.

3) The Indications point to a press problem.


Regards, Alois

* Mr Roskam, I suggest you read the PDFs I have posted

 

[Lukas Engqvist]

@Alois Ty for spelling clarification, but I will have to contradict you on that tack can in fact remove image area. Now if it was a combination of tack, and a certain paper type I can't say for sure. But there was one regular job printed on a certain stock that we needed to either print when the machine was warmer (meaning the tack was less as viscosity increases and stickyness decreases with heat) or if we needed to run that job first we needed to swich to more fluid/less tacky ink. Now you may have some scientific reason saying that it was not so… but I have real world experience of that fact.

 

[RGPW17100]

Your post mention that you have been running the same ink for the last two weeks. Why the new ink. What ink are you running? A change in ink could be your problem

 

[Alois Senefelder]

Fundamental

Fundamental

Hello Lukas,

Litho Plate Coatings ---

1) The image coatings must be wear resistant, solvent resistant and unaffected by fount solution additives.

Phase Change Coatings --

2) Infrared radiation is used to convert a soluble coating to a insoluble oleophilic image ---
thermal coatings consist of various heat-sensitive resins.

Quote " ......but I have real world experience of that fact" Lukas Engqvist

*** Well, being a Sorcerer's Apprentice for seven decades ---- what can I say !


Regards, Alois


"Remember the tortoise --he only makes progress when he is sticking his neck out"

 

[TF019]

Azura TS

We have been running Hostmann inks for about 6 months, the batch of inks we have been running for the last two weeks is from the same lot number. I should of clarified this point.

The job in question going back on press tonight as the client made some changes to their file. So all of the work we have done is billable and we are starting from scratch (15% of prior run ends up in the recycle bin). Sometimes even us printers get a break once in a while. Sigh...

If the issue continues to pop up I will continue to post but we have run 6 jobs since changing the C and M units and have not had any problems since.

 

[Lukas Engqvist]

@Alois, yes in principle I understand your quotes, and I'm sorry if I use a too casual way to express myself.

As I explained there was a situation where a certain ink /paper /temperature caused abnormal wear on plate. Now if it was the fount solution or the fount solution reacted with somthing in the coating I cannot say. I heard the discussion going on about the grind of the pigment in the ink also being a possible culprit (it could be more than just the tack in the ink differing or the tack/viscosity giving abrasive quality… but here we are getting into hairsplitting semantics where what I was trying to express was that there was something going on in the shadowlands between chemistry and physics on the press). Since either changing the stock, the ink to a less sticky variant or sheduling the job for when the press was no longer cold, meant that the job would run normally, I do not see how any theory would change that. Now there could on a microcosmic analysis be even more complex issues at stake such as thick sticky ink pulling off coating from this particular paper stock causing it to guild up on the blankets which would then have an abrasive quality on the plate... I did not go into the molecular levels (I neither have the knowhow or apparatus) But the NET effect was that any of thethree variables: a low tack ink, higher temperature press or different stock made the necessary difference.

I do understand that a Litho plate should not react to press chemicals, and that they are rigourously tested. But there will be extreme circumstanses, and in those cases it is importat not to hold fast to what SHOULD be but to consider what MIGHT be, so that you can try the different possible scenarios till you find where the problem lies.

(I find it curious that just switching magenta and cyan printing order should circumvent the problem. What has changed between the units...*the paper is a little more damp, and there is possibly a thin ink film of magenta on which the cyan is printed on, which means the paper will not stick as hard to the blanket, which in turn means less chance of build up of paper particles on the blanket... which means less risk that there will be anything abrasive on the plate image areas... but true this is just speculation...)

Hope TF019 gets the job through

 

[FujiFrank]

I would suggest that it is the lack of water pickup in the ink that is causing the wear. Even though you are not changing ink, your ink is changing around you. If you test the same ink in a medium tack, you may see different results.

Ink that is NOT taking up water is not properly emulsified. If it is not emulsified then it has a more coarse nature and will wear on the plates in these Komori presses I believe.

Best of luck,