Please help settle a disagreement

[CClyde]

#1 and #2 are 45% bar on jobs run on same

press, K unit within a few days of each other.

Same stock, same side of stock, same bar,

same CTP, same plate brand.




We are having a disagreement on the cause

of this and I've been asked to get the opinions

of professionals without my opinion so as to not

lead or sway the answers.




Any input would be greatly appreciated.

 

[curiosity]

can we assume:
plate images are identical?
FS conductivity the same?
press settings the same?
ink the same?
nothing unusual done at press between printings?

Obviously, the aforementioned (and so much more) can impact printed results tremendously, so...can you share more info?

 

[Guest]

Lot of variables to consider there. DEFINATELY look at both plates under the scope to see if there is a noticeable difference. That will at least eliminate that. It could even be that the plate chemistry has gone off and needs a refresh. We used to gum the plates and rehang the same set for potential repeat order projects.

If the dots on the plates look the same run to run, try a couple of different stocks on press to eliminate that. Almost looks as though the impression squeeze might be different or the ink might be emulsified. Hard to tell in the photo.

PRINTING IS FUN! .... (sometimes).

 

[CClyde]

Assume plates, chemistry, pressures, ink the same.

 

[curiosity]

well then, if nothing's different and everything is the same, obviously you shouldn't believe your lying eyes.
my apologies...couldn't resist.
however, the potential causes are numerous, but solutions should be readily available with just a little trial and error.
can I assume that you and your colleague will work together (perhaps via scientific methodology) toward a solution?
I really shouldn't even post this....it's Friday afterall...I need to leave.

 

[Cornishpastythighs]

Same operator?

 

[CClyde]

Same operator

We will work together.

 

[curiosity]

CClyde,
Maybe this helps your situation. I know you're just looking for support, and I'm assuming what I'll offer is already what you would do.
So here goes:

Everything's the same but results are different.
I suppose you suggested eliminating potential sources of problem.
Start with plating. Of course, examine, measure, etc. Try same plate on different unit. Check results (but results, if different/improved point to the unit).
If same results, try new plates from different lot. Check results.
If same results, you can repeat if you want, but chances are pretty good it's not the plates.
If you both agree, then onto troubleshooting the press. And of course, that is where the fun begins.

Anyway, hope you can provide the anecdote sometime in the near future. It's always interesting to see how issues get resolved.

 

[turbotom1052]

what does it look like if you pull about a dozen sheets in succession? Does that same patch look the same from the first sheet to the last? Im betting that you will see some variation. If so then my next question would be to ask if the paper that you say is the same, is truly the same. Im not questioning the brand, or even if its from the same skid. Im asking if perhaps conditions between the stock have changed? Has the paper taken on a visible wavyness? Tight edges? If so then its no longer the same paper!!!

 

[cementary]

Is #1 the fresh ink and #2 is the ink after 24 hours without roller washing?
For me it looks like the worst case of waterlogged ink, like on the pic but after some time

 

[CClyde]

Thanks to everyone taking the time to suggest solutions.

I should have phrased the post more clearly.
The problem is something I think is well known and easily identified (with a scope- thanks again Gordo).
I have seen it many times and explained it to operators who've then fixed it.
My purpose in asking was to show this operator (skeptical of my knowledge because I don't run a press) via your answers here, that you don't have to be a woman to be a gynecologist.
I don't operate a press, but I can identify some problems on press. Some of which are not obvious to the operator or anyone without a scope and a method to test, recreate and then eliminate the problem.

 

[DeltaE]

So can you firgure out what the problem is from? Can you share it?

 

[CClyde]

No Title

I will share it shortly, I was hoping for a few more people that know to jump in.

Here's another sample of the problem as it progresses. bottom image is @ 25% dot

 

[Alois Senefelder]

Hello CClyde,


Are you still using ..... Develop on Press Plates ?


Regards, Alois

 

[mwc]

If the plate image is not wearing down (scrubbed by excessive oscillation?) then surely a press issue here. I don't know all the proper terms...but I think the Fanatny rod needs adjustment or replaced?

 

[cementary]

If the plate image is not wearing down (scrubbed by excessive oscillation?) then surely a press issue here. I don't know all the proper terms...but I think the Fanatny rod needs adjustment or replaced?

Fanatny rod is definitely needs a replacement. Also you should make a Paper Clame and probably call for a S.I.C.K certificate

 

[CClyde]

Using Kodak Sonora XP, on press develope/cleared.
The same plates will produce excellent dot after problem is fixed.
It is a press problem, operational, not mechanical.

 

[Alois Senefelder]

Hello CClyde,


If this in your opinion is a press operation problem, why are the press crews unable to rectify the problem ?????


Regards, Alois

 

[cementary]

Hello CClyde,


If this in your opinion is a press operation problem, why are the press crews unable to rectify the problem ?????


Regards, Alois

For sure it'a because Mr cclyde is lack of authority

Mr cclyde will you share with us your point on this operational problem?

 

[turbotom1052]

Thanks to everyone taking the time to suggest solutions.

I should have phrased the post more clearly.
The problem is something I think is well known and easily identified (with a scope- thanks again Gordo).
I have seen it many times and explained it to operators who've then fixed it.
My purpose in asking was to show this operator (skeptical of my knowledge because I don't run a press) via your answers here, that you don't have to be a woman to be a gynecologist.
I don't operate a press, but I can identify some problems on press. Some of which are not obvious to the operator or anyone without a scope and a method to test, recreate and then eliminate the problem.

You may not have to be a woman to be a gynecologist, but it is advisable that you know the ins and outs (no pun intended) of a vagina.
How you get that knowledge can come from many sources. You may not need your own vagina to learn how one works, but it is advisable that you at least spend a little time studying a few. The problem with a lot of the info on the internet is that you find many keyboard commandos thinking that google is their friend, without knowing the source of the google info, or how to apply the info to a particular situation. If your pressroom is staffed with competent employees, then I would suggest that you take them at their word. If you lack any competent pressroom workers, then I suggest you find some. This will allow you to focus on your own job in the company, and in the process perhaps not piss people off. It still baffles me that some companies will hire less that fully experienced pressroom personell with the thought of saving a few bucks, in the cost center that is usually the highest in the company. At the very least there should be a fully competent pressroom supervisor that can solve these issues based on experience actually DOING the job as opossed to reading about it.