Plates wear out after 80k-100k

[lyzan]

Hello everyone,

I have some problem. I am using Agfa Polaris XTV with LP82 ULTRA OLP and our press supervisor is complaining about plates wear (silver violet) out after 80k-100k copies of running a newspaper (KBA press) on black plates only. I called the attention of our supplier but it seems that all parameters of the OLP is correct. My exposure is correct. LP82 is well maintained.

What I noticed on the plate is the image area looks like "reddish black" not a "neutral black". Do you think this is the reason of plate wear out? If this is the reason, how are we going to address this? LP82 Ultra has no developing time (speed) and temperature adjustments as our supplier told me.

I do not have this problem with our Agfa Advantage with LP82 OLP.

TIA,
Lyzan

 

[Armya Inc]

Hello everyone,

I have some problem. I am using Agfa Polaris XTV with LP82 ULTRA OLP and our press supervisor is complaining about plates wear (silver violet) out after 80k-100k copies of running a newspaper (KBA press) on black plates only. I called the attention of our supplier but it seems that all parameters of the OLP is correct. My exposure is correct. LP82 is well maintained.

What I noticed on the plate is the image area looks like "reddish black" not a "neutral black". Do you think this is the reason of plate wear out? If this is the reason, how are we going to address this? LP82 Ultra has no developing time (speed) and temperature adjustments as our supplier told me.

I do not have this problem with our Agfa Advantage with LP82 OLP.

TIA,
Lyzan

I wish I was in your site, but I am not. This could be from Prepress or Press side.
On the Prepress side:
Did you reduce the Finisher or developer on LP-82 in order to save on chemistry costs?
If your Processor LP-82 is within range which I doubt to be, I will need the PH measurement of the Developer and the Finisher. I'd also like to know if you are using the concept 6(Developer feeding in wash) or concept 7(Finisher feeding in wash). Lack of enough finisher applied on the plates can be one of the reasons. The Rollers specially in Finisher and Rinse section might have high pressure on the plates due to malfunction on Bearings' springs(Rollers are sitting on the bearings). If foam from wash tank feeds into finisher section that might be one of the cause of the problem.
It is better to clean your Spinner and align the optics.It is much more than an exposure test. Also having 1X1 on Digiwedge a bit darker can help on plates run length. Do not under expose the plate in order to get 1x1 very dark as it might effect the Shadow areas.

I also would like to suggest before installing the plates on your Press Machines, ask your press man to apply some Finisher evenly on the plates and let it dry.

Hope this will help!

 

[Cornishpastythighs]

Plates themselves dont know if they are on a black unit or a cyan unit, if you are only wearing plates out on the black print unit your press supervisor may have to look at the press as the cause of the plate wear. There are many reasons why plates wear out that are in no way related to pre-press.
Blankets and squeezes
Stock
Ink
Rollers and settings just to name a few.
Has the problem just started ? if so what has changed
Good luck

 

[Hopkins Printing]

Although there very well could be a problem with your plates/processor...I agree with Cornish. It's all too convenient that the pressroom puts the blame on Prepress for their problems.

As Cornish pointed out, you did say that the problem is only with black plates. Do you have a press with more than 4 ink units? If so, have your pressmen move the black plate to a different unit and see if the problem persists.

Best regards,
Jon

 

[schenkadere]

sounds like a press issue...abrasive ink, solutions, etc. Have you recently changed ink manufacturers?

 

[lyzan]

Hello everyone,

Thanks so much for your reply.

I am very sure that this is a prepress problem.

Technicians from our supplier came again last night and they removed roller no. 4. We print a test form and the plate has now "neutral black" on image area.

It seems that Armya is correct on the roller pressure. Roller no. 4 on LP82 Ultra is on developer rack. This is the top roller going out to diffusion section to wash section. So I guess, we are using the concept 6. We are on the exposure procedures base on best practices and IFRA guidelines. Thus we are doing as what Armya told on digicontrol.

I now have another question. It seems that the technicians of our supplier are keen to leave the processor without roller #4. For me, this is a BS workaround. Why don't they adjust the roller pressure? Is it correct that there is no way to adjust roller pressure on LP82 Ultra? This machine is only one and half year old.

Thanks again.

________
Lyzan

 

[Armya Inc]

Hello everyone,

Thanks so much for your reply.

I am very sure that this is a prepress problem.

Technicians from our supplier came again last night and they removed roller no. 4. We print a test form and the plate has now "neutral black" on image area.

It seems that Armya is correct on the rollers pressure. Roller no. 4 on LP82 Ultra is on developer rack. This is the top roller going out to diffusion section to wash section. So I guess, we are using the concept 6. We are on the exposure procedures base on best practices and IFRA guidelines. Thus we are doing as what Armya told on digicontrol.

I now have another question. It seems that the technicians of our supplier are keen to leave the processor without roller #4. For me, this is a BS workaround. Why don't they adjust the roller pressure? Is it correct that there is no way to adjust roller pressure on LP82 Ultra? This machine is only one and half year old.

Thanks again.

________
Lyzan

Hello, Your Service Engineer can't adjust the pressure on the rollers. This wasn't considered at Gilbos when they manufactured the machine.There is a reason for this. I can discuss this in detail if you ask me to, but the Silver Halide plates are very sensitive to rollers' pressure. The roller sits on 2 holders( we call them bearings) on left and right side. There are 2 springs in each bearing . After a while the springs due to chemistry evaporation or slug get stiff and loose the preset pressure values. Replace the bearings with new ones or buy some Car brake oil(can be purchased from any Automotive shop) and apply a drom( not to much) to the springs and wait for 20 min before putting the rollers in. Not to mention, you shouldn't have the Chemistry inside the Trays while doing this procedure. In most cases the springs start to work, but it is not the ultimate solution.The best is to change the bearings.This procedure can be applied to other bearings as well(Once every 3 months). Please note that all bearings for different rollers do not have the same Spring pressure . Make sure the Top and bottom Rollers are clean and in a good working condition as well!

Hope this will help!

 

[Armya Inc]

Hello, Your Service Engineer can't adjust the pressure on the roller. This isn't considered in Gilbos when they manufactured the machine. The roller sits on 2 holders( we call them bearings) on left and right. There are 2 springs in each bearings . After a while the springs due to chemistry evaporation loose their pressure. Replace the bearings with new ones or buy some Car brake oil(can be purchased from any Automotive shop) and apply a little( not to much) to the springs and wait for 20 min before putting the rollers in. Not to mention, you shouldn't have the Chemistry inside the Trays. In most cases it works, but not the ultimate solution.This procedure can be applied to other bearings as well. Please note that all bearings for different rollers do not have the same Spring pressure . Make sure the Top and bottom Rollers are clean and in a good working condition as well!

Hope this will help!

Please open the attached file for the bearing's picture. Please note the bearings. Both #8 and #15 look identical, but they have different springs with different pressure built in them . Some Springs used in bearing have different stiffness or ultimately different Pressures(N/cm2).

Hope this will help!

 

[lyzan]

Thanks, Farshad.

 

[Armya Inc]

Thanks, Farshad.

My pleasure!