Ink build up on edge of plate cylinder

Good after noon,
I am running a presstek 4995a-ICS 4 color press. I have been having problems with ink building up on my plate cylinders which in turn tranfers to all my cyliders. The ink then gets into my ink rollers. Its a problem because black will get into my yellow ink. cyan will get into my magenta. I have tried cleaning all the cyliders with chrome cleaner and desensitizer but nothing seems to work. Any suggestions on what else to try. Other than getting plates that cover the whole cylider. I am using polyester plates.
Thanks for the help.

 

are the ends of your ink fountain leaking? A leaky fountain will allow ink to run all the way down till it gets on the edges of your cylinder. You also might want to be sure your ink form rollers are set with minimum pressure to the plate. Be sure that your your not running emulsified. An emulsified ink film will be more likely to "mist", and be much thicker that an ink film with proper ink water balance. Ink buildup on the edges of plate cylinder tend to be like a cancer. Once you get a little spot of buildup it becomes a high point that will draw more ink to it. Im very meticulous about keeping plate and blanket bearers clean and the valley in between the plate edge and the bearer free of ink buildup for that very reason.

 

Check your ink and water balance for solution of your problem or you can find more details here