[Misc] plate trouble

[paul the printer]

have rn2550, been working perfectly well until last two jobs, after about a thousand run, horizontal lines appear on back of sheet,
plate has wrinkles on trailing edge, i straighten them out, runs alright for a while, but problem starts again, could it be to much pressure on pressure roller,
and why would it alter.

[RICOHMAN]

Re: plate trouble

Hi i repair duplos and the problem seems to be your pressure roller try taking the press roller out of the machine and clean the roller with solvent to remove ink which builds up on the roller this should cure your problem

[jermyth]

Re: plate trouble

I agree with ricohman, but riso impression rollers can have problems with some cleaning solutions. I recommend just gently scrapping off the ink buildup with a metal ruler or something with a non-sharp edge. As to why, impression rollers do wear out over time and they get ink buildup from the drum and/or second side printing too.

It is also possible the drum is over inking the screen and causing the master to wrinkle.

One answer that no users likes to hear is just make another master, but it is an option if you can't get a tech to fix your problem.

[paul the printer]

Re: plate trouble

sorry ricoman & jermyth, not getting back to you, i had to wait for holidays to try your suggestion, cleaning the pressure roller worked like a charm, big thanks to you both, and jermyth, i am an offset printer, and i used a product we use for the dampening system rollers it is a solvent for rubber cleaning and conditioning, it would be available at graphic art suppliers.

[paul the printer]

Re: plate trouble

sorry forgot to tell you the name, it is called maticlean.