odd line appearing on sheet

[printr640]

I have been experianceing an odd occurance on press. 3 and 3/4 of an inch back from lead edge of sheet I am getting a faint line that runs all the way across the sheet.(line is 1/4 of an inch wide) same place on sheet everytime. It appears very faintly and slowly goes away as i run. Today I ran about 4000 sheets and it was all but gone.
this just came from out of nowhere i have made no changes.
can not see it on the plate but does show up on the blanket.
i have tried changing water mix and this helped somewhat but did not fix.
any ideas?

 

[Richard]

Try de-glazing the blanket, check the packing behing the blanket.
It couldn't hurt, if you don't see anything on the plate.

 

[printr640]

New blanket and packing did not help

 

[Richard]

If using a metal plate, clean the area with the developer.

If using poly plates clean area with the stabilzer

 

[GazKL440]

Checked all your rollers settings? might be a water mark that can disappear as the press warms up and expansion combined with ink temperature climbing could (possibly) nullify the effect, hence the improvement over 4000 runs or so...

is it more prevelant in screens or solids? if changing water helped that points towards a dampening problem, check your technotrans is dosing properly we have the odd issue with the filters filling up and first sign is water marking or scumming

 

[mikesmoker]

I get a similar effect when running thin vanson inks. It usually goes away if I tack them up a bit and/or run the ink in dry for a bit to tack it up. Rhodamine, 032 seem to be the worst.

 

[turbotom1052]

line near gripper

line near gripper

are you sure the line is not on the unprinted sheet?