Processless plates and dot gain.

[Shurup]

Greetings!
We are using Magnus 400Q with Fuji Pro-T and Kodak ThermalDirect plates. After on-press development on MAN Roland 510 or on SM 74 we are having dot gain about 24% on every ink. After 1000-2000 prints made dot gain drops down to 17-18% and stands still for about 50 000 sheets. We are thinking about washing problem but have now idea what to start with. Any advice will be appreciate

 

[couriergraphics]

Sounds like your plates are not fully cleaning out on the press. I would check with the manufacturer to find out if your fountain solution might not be doing the job of cleaning up the plates on roll up?

 

[Shurup]

It is quite reasonable that the problem is in cleaning and the first thing to start with is to check the fountain solution, but we didn't meet any help from the reps of the suppliers, so we'd like to solve the problem ourselves. We have some tools to check pH, conductivity and so on, but we need to know the values we need to achieve. Now we have exactly the same values we used many years with process plates and it seems that something should be changed.

 

[Derek@Kodak]

Processless plates and dot gain

Processless plates and dot gain

Shurup,

We need more information on your situation and I would recommend calling your Kodak sales rep or dealer to escalate this issue to a Kodak plate specialist.

However, the imaging settings for the Fuji plate are very different than for Thermal Direct. So are the plates being imaged correctly?

Also if the plates are exposed to white or yellow light beyond the recommendations, they will begin to print full and then sharpen up, however they will also be very slow to develop-on-press.

Also are you washing the plate? If yes, that could also explain the full plate at start-up. If the Kodak Thermal Direct plate was left in white light and then run though the wash-out unit (which is not supported), the coating would not fully remove and will print full at start-up and wearing back as the job is run.

 

[PACH]

Shurup,

We need more information on your situation and I would recommend calling your Kodak sales rep or dealer to escalate this issue to a Kodak plate specialist.

However, the imaging settings for the Fuji plate are very different than for Thermal Direct. So are the plates being imaged correctly?

Also if the plates are exposed to white or yellow light beyond the recommendations, they will begin to print full and then sharpen up, however they will also be very slow to develop-on-press.

Also are you washing the plate? If yes, that could also explain the full plate at start-up. If the Kodak Thermal Direct plate was left in white light and then run though the wash-out unit (which is not supported), the coating would not fully remove and will print full at start-up and wearing back as the job is run.

I agree with Derek regarding the plates. There should be different settings for the plates in the ThermalII Head. i.e. Surface Reflectivity/ LaserPower/Drum Speed/ etc.

 

[Shurup]

Derek@Kodak,

I do know that the settings of imaging unit differs much for this two kind of plates. We do expose and store plates within the "yellow light room", never store them exposed longer than one day, never use processor or any other wash-out unit. We just take them to the press, mount them, keep the press revolving for about one minute while applying fountain solution, then engage ink rollers and let it run for about one minute too, then we start to run stock. The thing with the decreasing dot gain after 1000-1500 and than standing still for up to 50-60 thousands on two different plate types (Kodak and Fuji ) let us think than all Magnus exposure settings are Ok, but something to be fixed in developing on press procedure.

 

[Kent Walker]

If they are unable to resolve this issue, I recommend the Agfa Azura TS plate. These plates utilize a different technology (Thermofuse) and the Wash-Off unit eliminates all of the on-press issues.

 

[Raymond Ramirez]

As they suggest I would have someone onsite. Understand that normally if its a fountain solution problem the image will eventually dissapear. If you are telling us that the image loss is happeneing from 1000-2000 impressions but holds when it gets to a certain percentage then its not the fountain. if its consitantly doing this I would have to say that the power to plate is either to high or it is out of zoom and or focus. The outside edge of the dot is being eaten away because there is no validity to the dot exposure at the edge because the dot is out of focus or there is flair from the beam. Since this is a proceless plate this is harder to see. and a few test on press would confirm this. Make sure you have alot of makeready sheets to test this. you may contact me if you need assistance

 

[Raymond Ramirez]

At this point I dont recommend you switching. everyone who post to this site is always trying to switch people to there better product. Lets get you answers so that you may understand what is going on. Not switch you to another set of issues.

Every Manufacture has there issues. no one plate is totally perfect. There are certain enviroments that cause plate and press problems.

I am sure we can get through this if both plates are showing the same symptoms. I am sure that either the Fuji or Kodak plate will work for you its just finding the right setting

Raymond

 

[Raymond Ramirez]

Derek
may have a point. the pressman maybe washing the blanket with something that is eating the plate and it is eventually washed off with the fountain at a certain number of impressions but not untill it takes its toll on the dot. Normally this might not be seen but you may have a few things going on. being out of focus and a wash problem Hmmmm. I wonder

Maybe I just full of it

 

[Derek@Kodak]

Processless plates and dot gain

Processless plates and dot gain

Raymond,
Thanks for chiming in on the pitch to switch. I try not to do this even when I see posts concerning the weaknesses of my competition. I always encourage printers to chime in on what works and what doesn’t work, but when the suppliers and vendors do it it takes away from the goal which is helping customers.


Shurup,
Based on your last posting I would look at the steps that you are taking to develop the plates on press. The excessive pre-damp (one minute) and pre-ink (additional minute) may be emulsifying the ink which in turn will make the dots look like they are printing very full (24% gain). It would take approximately 1000 sheets for the emulsified ink to work its way though the press. With fresh ink in the press, the print would be much cleaner and the dots will print with normal press gain (the 17-18% noted). With what you have told us I suspect the ink is being emulsified.

Try mounting a fresh set of plates on press and start the press in a normal manner. If the press is equipped with an auto start feature, use the auto start. If only a manual start is available, idle the press, drop the water forms to the plate for 10 revolutions, then the ink forms for 10 revolutions and then go on impression. This should be sufficient assuming that the press is set-up correctly and the fountain solution is mixed properly.

But again, a Kodak plate specialist will be able to help when visiting on site.

- Derek@Kodak

 

[nycku]

Greetings!
We are using Magnus 400Q with Fuji Pro-T and Kodak ThermalDirect plates. After on-press development on MAN Roland 510 or on SM 74 we are having dot gain about 24% on every ink. After 1000-2000 prints made dot gain drops down to 17-18% and stands still for about 50 000 sheets. We are thinking about washing problem but have now idea what to start with. Any advice will be appreciate

Hi!
Are you measuring your dot gain in the plates may you are gaining too much you probably need to make linear curves ! Do you guys use densitometer to read plates? Gaining on the plates is different from not cleaning out on the press ,even if it is not cleaning out your 50 is still 50 no matter what . We use fuji plates and Nexus workflow we do linearize our plates with our curves compensations based on the printed test that we make.

 

[tkarg]

If I may ask, what country are you in? Have you spoken with the Fujifilm tech service department in your area? I'm surprised that you would not be getting local support. If you contact me offline, I'd be happy to connect you with someone to escalate this for you.

Regards
Tony Karg
Sr. Director of Business Development & Marketing
Fujifilm Canada (Graphic Systems)
[email protected]

 

[PACH]

NYCKU,
What densitometer reading you are talking about? They are using PROCESSLESS plates!!

 

[Shurup]

First of all we won't switch to Azura + Processor because we do not have room for it and do not have person to clean the processor.
Now I'll take time out to make some tests to have some more statistics. We do know about calibration curves (Harmony) for CTP, but seems it is not an issue.

Derek@Kodak,
Maybe I has exaggerated a little about a minute, but a think the press makes about 20 revolutions while pre-damp and the same while pre-ink. We tried to develop the plates the way you advice before with the same result.

Last week we tried to use FountMax Blue 30.10 PRO-T fountain solution, but nothing have changed. Now we want to try Fuji QC-1 Quality Checker with plate densitometer to check the dot gain of "manually" developed plates.

tkarg,
Tony, I'm in Russia and sometimes it is hard to find really good support here, so I try to find a solution from the primary source.

 

[tkarg]

Dear Shurup:

Now that we know where you are, you can be assured that our European colleagues are speaking with the local Fujifilm team to ensure you get the support you need. You should hear from our team shortly.

Thank-you for being a Fujifilm customer.

Kindest Regards
Tony Karg
Sr. Director of Business Development & Marketing
Fujifilm Canada (Graphic Systems)

 

[Derek@Kodak]

Shurup,

I will escalate this through the Kodak European support organization.

Thank you for your business.

- Derek@Kodak

 

[danremaley]

measured plates

measured plates

Greetings!
We are using Magnus 400Q with Fuji Pro-T and Kodak ThermalDirect plates. After on-press development on MAN Roland 510 or on SM 74 we are having dot gain about 24% on every ink. After 1000-2000 prints made dot gain drops down to 17-18% and stands still for about 50 000 sheets. We are thinking about washing problem but have now idea what to start with. Any advice will be appreciate

Are these measured gains at the 50% area or the 70% as Heid./ Man/KBA use?

I'd love to talk to the engineers that devised these plates - have they ever heard of Edward Demming, and his demand for quality! Demming taught Toyota that you produce quality and don't pass the product along until it's measured and correct. So how does prepress measure and check these plates prior to delivering to the pressroom? Bad idea.
Dan Remaley
Consultant
412.889.7643

 

[Shurup]

Are these measured gains at the 50% area or the 70% as Heid./ Man/KBA use?

I'd love to talk to the engineers that devised these plates - have they ever heard of Edward Demming, and his demand for quality! Demming taught Toyota that you produce quality and don't pass the product along until it's measured and correct. So how does prepress measure and check these plates prior to delivering to the pressroom? Bad idea.
Dan Remaley
Consultant
412.889.7643

Dan,
24% dot gain measured at 50% on R500. On SM we have 70% field in the control strip, we have less gain than 24% but it is greater than it should be. And let me remind that it comes into normal values after several thousands.

 

[Lukas Engqvist]

First of all we won't switch to Azura + Processor because we do not have room for it and do not have person to clean the processor.

Having a person to clean the processor? It is not a full time job I do that in under an hour once a month. I do a more thorough clean than prescribed, because i think it is an investment in trouble free operation.