Solution to resolve dirt marks on Newspaper

[sierra24]

Hi,
We our encountering dirt/oil marks on our Uniset Press, usually on the low copy (plate & blanket gutter meets). We have isolate the press to manual washing and doing only 1 time roller wash, but we the problem still persist.

Have any member encounter similar problem with their press.

cheers
mike

 

[maas]

I suggest you first distinguing what the marking is, i.e. if its oil or dirt. have a smaple analysed in a lab

Also see if the location is aproximately the same everytime and going with the rotation or against it

If its oil; take out the web and run the press ( clean it first) and look for oil splash

if its dirt; this can come from various sources, seems you have all the usual cleaning in hand so look for outside the box i.e.if you have a gantry crane has this been used recently and any dislodged dirt which could have fallen down.

best of luck
maas

 

[gossboss5501]

Are you sure that this is not your folders cutting blade?

 

[sierra24]

We are 100% certain its from the unit/couples, it orginating from the plate notches.
We have ask Nela to make some adjustment, but does not seems to work.

 

[BeauchampT]

I'm not familiar with newspaper presses, but I ve seen similar things on web presses I've worked on. I take it the residue on the back side of your plates is oily to the touch??? If it is, my question would be, do you have any automatic oiling/greasing systems in your units? Or, how frequently do you oil your plate/blanket gaps?? Excess oil and grease will seep behind your plate and come out on the run. And it would explain why it only shows at your gap.

I worked on a Hantscho where our bearer felts and their oilers would get some damage and start to drip oil on the run. Would look like very intermitent spitting. Don't know if that is helpful, but, it is a place to start looking for mechanical problems.