some parts of Image area not accepting ink

[aditya deshpande]

I am using Fuji Violet plates. The problem has occurred in some parts of image area. Three months back i had same problem. So i cleaned machine 2 - 3 times and then that problem was solved.
But this time it seems different. Plates seems to be correct. Do let me know what to do and what to check.
Thanks is advance.

Regards,
Aditya

 

[Ajax]

Are these new plates or old gummed in plates?

 

[4stateprint]

Check your fountain. Had a bad spot on roller once and it caused similar problem. Also could happen if fountain rollers are dirty. I agree with Ajax, it would help to know if this is a new plate or an old one. If its old the plate is bad. If its new and its not the dampening system, it could be the plate manufacturer. I have had that problem before as well had to send a whole box back. Pain in the neck. Best thing to do is make certain everything is clean and operational then trouble shoot from there. Good luck.

 

[HPC]

We had plates a long time ago that had this issue. No matter what we did, plate blinding would occur every time the press was shut down and started. Kitchen cleaner, I think it was Comet at the time, would get the plate back, but do it a couple of times and it would be gone forever. The plates were bad, once we switched brands the problem stopped. You might want to check your fount solution to make sure your not running too far off of 4.5 ph.

 

[Armya Inc]

I am using Fuji Violet plates. The problem has occurred in some parts of image area. Three months back i had same problem. So i cleaned machine 2 - 3 times and then that problem was solved.
But this time it seems different. Plates seems to be correct. Do let me know what to do and what to check.
Thanks is advance.

Regards,
Aditya

Is it a Polymer violet plate or Silver halide violet plate?

 

[aditya deshpande]

Thanks you all for your valuable posts.
I am using silver halide violet plates. The said problem occurred with set of new plates. Old plates runs without any hesitation. I had checked all the parameters related to dampening i.e. pH, fountain % and IPA %. These were all in correct composition.
I spoke with my plate supplier about it. Then he told me that he uses plates of two brands. So he needs to change plate developer frequently. So i might think the problem lies here in developer. Obviously plate suppler is not agree.
So i have switched to new suppler who provides Thermal plates now. Problem not occurred from last 10 - 15 days.

Thanks & Regards,
Aditya