Un-solvable Picking Issue?

[Cameron]

Hello Everyone,

I frequent the forums looking for solutions when we have problems, but though anything I can find on here, plus anything we try through suppliers, we can't seem to solve this problem.

No matter what we do, when we have a 2 sided job we cannot back it up untill a couple hours later. If we try and back it up any sooner the ink will literally pick up off the sheet and build up on the cylinders. The sheet remains in tact.. but jsut the ink picks off.
We are running our full color work on a 14x20 gto, agfa azura plates.

Things weve tried:
lowering from 175 lpi to 150
changing the chiller temperature from 55 - 60
Every Line of hossman ink, flint ink, van son ink. Including heavy dryers and or low tack ink.
Different fountain solutions, one step from hossman, 2 step from unigraph, alcohol sub, alcohol.
Cleaning the cylinders with heavy duty cleaners.
Coating the cylinders with spray silicone and other overnight coatings.

I think that covers about everything. I feel like we've tried about everything we can try. Does anyone have any suggestions for us? Any help would really be appreciated.

The only other thing we've noticed that might be worth mentioning is that our 2 color gto perfector is almost identical to it except that the cylinders have a jacket on them that is a very dull finish as opposed to the 4 color that has no jacket and is a shiny chrome finish.
And an added note is that our ph is around 4.5 and our conductivity is around 1000.

Really really appreciate any help anyone can give us. We have put weeks of testing towards trying to solve this problem and cant make any headway.

Cameron

[rbailleu]

have you tried superior elite lt or evolution lt or heidelberg safira select lt
we run work and turn on our sm 52 every day. we do have a ir dryer

[dabob]

In my experience it depends more on the paper than anything else, are you having problems with uncoated or coated . . . or both . . . do you have an IR dryer. We can turn coated sheets very soon after printing on both of our speedmaster 74s with dryers but on an uncoated sheet its gotta sit overnight . . . ink does need some time to dry - its just physics

[Cameron]

we used to use the safira a while back and were experiencing the same problems.. we dont have an ir dryer or anything though.

the uncoated stocks actually back up better than the coated. the ink absorbs into the uncoated, where it seems like it just sits on top of the coated sheets and peels right off when trying to back up.

And what would you consider norm for backing up? we wouldnt be able to back up any short run work sooner than 2 hours after it was run. It never used to be like that, we used to be able to run a job and maybe wait 15 or 20 minutes to back it up. and according to other local printers they are still able to do so, unfortunately for whatever reason we are not.

[rbailleu]

cylinders should not matter for most things. cylinders are chrome on a straight machine. the perfect jackets are only after the perfector on perfecting presses. which is obviously wet on wet at 5k+ iph. we turn in 15 minutes on enamels all the time. dryer does help. heavy coverage 250% + will be an issue with out a dryer, but 100% should not be an issue. most modern inks should do it.

[Cameron]

thanks for the info on the cylinders.. that clears it up a bit, its definetely happening with coverage... a solid of one color isnt usually a problem, but when its layers of all the colors it is especially bad.. is there something i dont know about as to limiting the ink level somehow in the file? should that be necessary? blacks are especially bad if they are made up of all colors, but its not limited to taht.. ran a full green today that was mixed and the sheet looked like a snow storm.

we are going to try a few other stocks hopefully tomorrow morning and see if there is any difference at all..

[nhprinter]

Hi Cameron,

A couple of suggestions:

Talk to your ink manufacturer. See if they have another line you could try. If you were just having the problem with process colors I would suggest Superior's Biolocity line which dries better than any ink I've ever used, but they don't make it in PMS colors.

Conductivity seems a little low. We run around 1500 with a 1 step solution. Ph at 4

Try adding a good drier to your ink or fountain solution.

Good luck,

Dave

[Bob Peterson]

Hi Cameron,

A couple of suggestions:

Talk to your ink manufacturer. See if they have another line you could try. If you were just having the problem with process colors I would suggest Superior's Biolocity line which dries better than any ink I've ever used, but they don't make it in PMS colors.

Conductivity seems a little low. We run around 1500 with a 1 step solution. Ph at 4

Try adding a good drier to your ink or fountain solution.

Good luck,

Dave

FYI - Biolocity PMS colors are currently out in the field, currently finishing up beta testing, running with excellent results. Contact your Superior rep.

[rbailleu]

I agree use the superior biolocity or evolution. try to cut the rich black to less cmy

[turbotom1052]

my suggestions would be to ...
A. invest in an infared dryer for the press
B. as someone mentioned try to reduce the c,m,y on them rich black areas to allow more black ink to carry the image as opposed to the c,m,y combination
C. use an ink set thats as highly pigmented as possible so as to minimize your ink film thickness.
D. have your pressman pay particular attention to his ink water balance so you can keep drying time to a minimum.
E. try to schedule that really heavy coverage forms towards the end of the day so it has overnight to dry