AGFA Azura TU Plate problem with run up

[contrakid]

Hi all

We have been having issues now with Azura plates and run up on press for the last year.

When chems are new they ink up around 80-100 run, after a week they start to not ink up for 100-200 sheets or more.

Minders now wipe every plate with plate cleaner before running to try and remove the TU Gum

FUJI plates we run previous inked up after 20-30 sheets

Best result we have had to date is running a mod processor with dual baths, first bath has scrub and Azura TU gum to dev plate out!, second bath has scrub and normal RC795a gum. But still plates would not ink up after 300m of plates till around 150 pulls unless press minders cleans gum off first.

Anyone else have this sort of experience with these plates.?

Our plates setter is one of the first XL105 and only 100mW power so it struggles to image plate and we have to run drum speed down, plus 3rd laser head is hard to balance to 1 & 2 as it seems very weak

Fun Fun Fun

Thanks in advance for any help

 

[Alois Senefelder]

Gum Blinding and Slow Roll-up


Too much Gum is being applied to the plate causing Image Blindness and slow Inking UP of the the plate , you need to check gumming roller settings.

USE LUKE WARM WATER and swab the plates using a soft clean lint free wipe to remove gum layer.

1) Rectify the Plate Imaging Problem


Regards, Alois

 

[contrakid]

Thanks for the reply.

I wish it was that simple, its something more complex to do with this CX Gum/dev and plate / fountain solution.

I'm looking for people running same setup that may have had this problem with AGFA TU plates and CX gum.

Do you run these plates and this gum?

 

[Alois Senefelder]

Complex !!!!!!!


All the CX Gum does is ........... Wash Out the Unexposed coating. 1) Is the plate being exposed correctly ? If not it could be "Residual Coating" not being removed

Regards, Alois

 

[contrakid]

Yes i'm wondering if it could be residual coating not being removed as when we wipe over with warm water we get lots of blue come off on cloth.

AGFA tell me this plate cannot be over exposed! I'm not so sure about this. Trouble is we have 3 laser heads that need balancing and one of the heads seems to be a long way from the other 2 on power and we are struggling to balance as need lots of press test time.

 

[Alois Senefelder]

!!!!!!!!!!!!!!

You need to worry about the "Unexposed Coating" ALSO rectify the Imagesetter problem, Why is there "Resdual Coating" left on the plate....... check the through put

of the Wash Out Unit




Regards, Alois

 

[contrakid]

AGFA seem to think its their problem as they have had a custom processor made for us with 2 baths! 1st bath has CX Gum and scrub, second bath has RC795a normal gum and scrub so really don't understand how it can still have coating on after all these processes but it does.

 

[Alois Senefelder]

Logic !


As I write this reply.......... thousands of square metres of Agfa Plates are being proccessed world wide successfully BUT you have a problem - so where

does the problem lie ?


Regards, Alois

 

[br549]

Have you checked stripes on a brush test?

 

[contrakid]

Yes stripes brush test is correct

Alois you are not really helping!

 

[DPS_GRAFIX]

Hi. I suggest you to check azura tu plate exposure value and focus settings on Ctp first.
If plate is underexpose, blinding ink effect could be an issue.

good luck

 

[contrakid]

We changed to just water in second bath so no gum on plate and slow run up went away. So now we are just running a 30% gum and 70% water and all still good. Going to try some other gums.

 

[SnoopDoug]

What was the issue with the Fuji plates? Run length? Performance?

 

[Alois Senefelder]

Hello contrakid,


GUM !!!!! use 8 degrees Baume Gum


Regards, Alois