Picture Framing on Sheet Fed Presses

[D Ink Man]

Please give examples of situations where you have run into this problem and the best remedy to curtail it. It normally is an accumulation of ink along the outside borders of the printed sheet, in the non image area. Your valued solutions are appreciated.

 

[SpeedKing]

sorry i have no experience of this but i am intrigued to know?

 

[rbailleu]

I was told once by a good well trained pressman that picture framing is too much fountain concentrate. toning over the whole sheet is too little.

 

[GazKL440]

we get a bit of this on the 40" on longer runs.. which means in general! Will try dropping fount a little, maybe half a percent, as rbailleu implies, as even tho it doesnt effect the print it does look ugly on the side of stacks.. ive tried different founts and inks with no real result, but put on a fresh plate and the issue settles for maybe 30k then slowly returns.. the problem with this is we do long runs with perhaps a million impressions on the CMY plates with multiple black plate changes,. The end result is shading on the stack edge but nothing to really worry about.. cleaning back cyl's and blankets more often prevents the excess runnin off the back edge and dripping onto transfers..

Any suggestions would be good thank you

 

[Albert Noel]

this can also be caused by excessive side to side movement of ink form rollers

 

[duct maestro]

What sort of speeds are you running at?

 

[Heidelberg]

As long as their are no mechanical reasons. Usually this is related to water quality (using RO water helps), and fount additives. High pigmented ink and higher tack grade helps too.

 

[SpeedKing]

i am familiar with picture framing on the impression cylinder and as suggested this is to do with the strength of the fount solution.

 

[GazKL440]

Tried pullin half a percent out of fountain solution, down to the minimum recommended level of 2% and reckon it made the framing issue a little worse if anything so will bump it back up to about 2.5% or so.. i reckon its the ink we run, Hostmann Steinberg Impression.. its a very low tack ink and i think it struggles with the ambient temp and steady 13000/hr, even with chilled oscillators etc ad good temp control from the technotrans..

 

[Al Ferrari]

Have you considered that it may be a plate problem? You are not by any chance running Fuji Pro-T plates are you? In some situations these do not get the background washed out so well, or get a weak background exposure from room light handling.

I have narrowed this down as the source of my picture framing.

Al

 

[Heidelberg]

You should take a deletion pen and delete the non image area outside of the paper size, and see if the same area remains clean on the blanket.

 

[Al Ferrari]

Yes that certainly is a good test. But beware that the deletion pen needs to be compatible with the brand of plate in use. Not all of them are.

Al

 

[D Ink Man]

It seems that it has been found that a less aggressive fountain solution can help. If you are using a 2 step, reducing the substitute portion in half (3 oz to 1.5 oz gallon water) may help. Not too soft of an ink body can also provide relief. You can have a relative low tack, say 12 or 13 on the last down color, but as long as you have good structured body that still transfers well, the picture framing can be minimized. Have seen some good results from Bottcher and Printers Service founts. Very interesting subject, please keep the thread going as experiences are presented.

 

[Al Ferrari]

I only recently switched over to CTP plates from analog plates, and I am using the Fuji Pro-T plate just because that's what is being used at this other shop near by where I get my CTP output. Both shops were having a toning/background/picture framing problems, and we just learned that we need to use a fountain chemistry specific for thermal processless plates, and that the the fountain solution for analog plates will not do. I was at that other shop today, and the problem seemed to be cured.

Check with your plate supplier about this fountain chemistry issue.

Al

 

[GazKL440]

You should take a deletion pen and delete the non image area outside of the paper size, and see if the same area remains clean on the blanket.

will look into that (and have a compatible pen) but wont be able to report back on it as first job up in morning is max sheet size and is about 400,000 run ( bout 85% coverage solid black on light gloss too) grrrr.. provided nightshift keep it together... may still have some of present job on in which case i will mark the plate as suggested...

I dont think it will be pre press issue, as other presses in the factory are running different inks and founts without probs using the same type of plate made in the same CTP and processor... unfortunately i dont get a say in ink purchasing, and the rep who services our requirements is a good mate of our production manager.. so i wont be able to trial other inks

I will look into the type of plate we are using, they are from XingGraphics but i dont know who supplies them.. they are a thermal plate not affected by light but still run thru a processor post the CTP, sorry i dont have more info on pre press, its all mouse clicks and magic to me lol

 

[[email protected]]

Please give examples of situations where you have run into this problem and the best remedy to curtail it. It normally is an accumulation of ink along the outside borders of the printed sheet, in the non image area. Your valued solutions are appreciated.

Im guessing this a CTP Plate and not a conventional plate ?
If its a CTP Plate go to the local hardware a buy a pint can of actone and drop a few drops on the non-printing part of the plate (back-ground) if it leaves a bluish hallow, there is coating in the grain of the plate and that will cause picture framing, when you make the drops, blow them to evaporate the liquid.
If the grain is clean,it is more than likely a balance of fountain solution, check conductivity
to be 1000 ohms over the water , most waters are 100 t0 300 oms. out of the tap, so
that would give you a starting point of 1100 to 1300 oms to start with
Another quick way would be to leave everything the same and add 10% alcohol to the
system,no alcohol sub. needed of course.

 

[realaqu]

I was told this is because improper ink and water balance, because you changed plate, maybe it is time to try a different wetting or fount solution

 

[Paultheprinter]

picture framing

picture framing

Hi there,

When i first started my job at my new company the picture framing was realy bad, to the point after 10,000 sheets the blankets were glossy with wet ink around the edges of the printed area, this cause ink to build up on the impressions and flick all over the grippers, it was an absoloute mess. We run a 5col SM74 with k&E inks on mainly 70gsm bond, the press runs between 10,13000sph for 15hours a day with no temperising rollers or climate control, ive seen ink temps up to 40 - 45 degres celcius. I tried a few chemistry changes to cure this but found no quick soloution, after a bit of reserch i found out than picture framing is the result of a oil in water emulsion and can be caused by too much preasure with the roller nips, i then dropped all the form to steels and to plate by 1 mm from standard spec and hey presto clean blankets. I have ran this with fount with silly high PH and conductivity levels with damp temps up to 20 degres when the compressor broke and even then i still ran clean and had great lift from the balnkets. the only time it reappears is if i get mega calcium build up and i mean mega, to the point that the rollers a white over 80% of the surface and up to the vibrator roller.

Paul

 

[Al Ferrari]

"... after a bit of reserch i found out than picture framing is the result of a oil in water emulsion and can be caused by too much preasure with the roller nips..."

Very interesting. Could you please give a reference or references for this? (especially the pressure part)

Thanks,

Al

 

[Paultheprinter]

hi there,

i shall have a dig and repost, it may have been in the book what the printer should know about ink available at all good book shops

Paul