ink problems?

[rocketmanjm]

We are experiencing a severe window paneing issue. Ink builds up severely around outside of sheet and on lighter weight stock also severly on bottom cyl. it is so bad we have a ink slinging problem on longer runs. (5000 sheets). We just change from Host. Stein 7250 series to perfexion series but we are having same issue with Superior and and special colors and wikoff vinyl process so we don't think it is a total ink problem.
We also just changed to a new kodak plate p0071 and new processor, we just tested a sword plate from kodak that was a little better .
Weare using anchor 2 step etch jrz arsf but have tried 2 different 1 steps with no big difference. We use day 3000 blankets and have tried a few others with no real help .
We have checked and reset roller stripes and packings and pressures.
Any other suggestions?

 

[macphenom]

Sounds like you have a severe ink emulsification problem. It sounds as though your fountain solution is attacking the ink something fierce. Try a fount that uses less solvents such as Allied chemicals "All Star" or "Hi-Fidelity" they have almost zero solvents. Also this can be caused by mechanical issues. Check your ink forms to the plate to make sure they are set properly to the press specs. Check your water forms also, if the mechanical can be ruled out then you can be pretty sure its chemistry.

 

[rocketmanjm]

We have checked and rest all form rollers. Tried a few different fount solutions (Subifix was one ) ink looks fine on rollers but still window paning we even have been cutting blankets on long runs thanks for the suggestions by the way the press is a heidelberg speedmaster 102

 

[Bob Peterson]

The problem you are experiencing is caused by precipated calcium cabonate. I have attached a zip folder that contains several articals pertaining to picture framing and other problems caused by calcium. I recommend that you perform the maintainace steps outlined in thses documents. You should no longer experience this problem providing that you incorporate these into your weekly press maintance program.

Bob

 

[macphenom]

Yea, I forgot about the calcium issue. We have been doing calcium cleans for a few years now because of the junk paper out in the market and I assumed everyone was de-calcifying. My bad.

 

[Lukew]

Bob, thanks for that info,,
It can also be caused from a poor quality ink,, example, one brand of say PMS 280 we get the picture framing very bad, switch to the other brand of PMS 280 and the picture framing is nearly completly gone.

 

[rocketmanjm]

Thanks for the info on calcium build up but We do use dyna a clean and relief and lime away and triple threat and hot water rinse on a fairly regular basis so I think we have some other cause in our shop. Is anyone using the p0071 kodak plate and if so what etch and blanket are you using?

 

[Paultheprinter]

I think the one point which has not been mentioned is the from roller oscillation, if there is any sideways movement of the roller on the plates surface you will get picture framing! I run a sm74 and when i started four months ago after 500 sheets the blankets were all shiny with ink in the non paper area. This was only solved when i ensured there was no sideways play in the forms, now it runs 80,000 without blanket washes or ink build up on uncoated. Saying this i have rollers which are covered in calcium, we have tap water at 700 microseimens and no ro unit yet and still i have eliminated picture framing the key was to reduce form to steel pressure down to 2-3mm, i know its out of spec but if rollers are old and hard then in my opinion any more preasure causes the ink and water to over mix and creates an oil in water emulsion giving toning. Its an easy job just to do and you should see result straight away.

Paul

 

[rocketmanjm]

None of the forms are in the oscillating position but there is slight end play in a few rollers will reduce stripe to see if that helps
Thanks keep suggestions coming

 

[Paultheprinter]

dont be concerned if the rider rollers are moving too much just the ink forms, if your suffering with picture framing / toning then other issues may be the cause. In my research it happens because there is too much water in the ink either because of an aggressive fount soloution or week ink resistance to water or a chemical reaction in the grain of the plate causing a desensitised non image area. From memory there is a wet thumb test which gatf mantioned in the book "what the printer should know about ink", i think it goes if you wet your thumb and run it over the nonimage area of a pre inked and damped plate and there is ink on your thumb after contact then the ink is picking up too much water? i may be wrong but it does ring a bell. What fount do you use? ipa free? and if so what sub? what % do you run fount ipa and sub? do you use ro? if so what % conditioner/re-hardner are you using if not what is the hardness of the supply? how often do you wash up? what chemicals do you use? what is the average temp of your print room? do you use chiller rollers? please give as much info as possible, there may be a simple reason for your issues and if i walked into your press hall and looked at your press and enviroment i could solve these issues but at home with a can of carling its difficult. The more info the better

Paul

 

[flyby54]

Hi
Just thought I would add my opinion for what its worth.
Have you made sure that the plate is fully exposed?
If you are getting these problems it could be a gradual build up of ink
off the image area, and you probably would not see it when looking at the plate
off the machine.
I have had this problem in the past when i changed plate types.
The guy who was making the plates didnt clean the proccessor properly.

 

[gauhar]

Reference to your problem, i think your water should be treated with R.O.Reverse Osmosis system,Check the T.D.S level of your tap water TDS level should be around 50 dosage of fount must be less than 3%..Secondly check the machine water metering roller is may not be desesitized properly.
Gauhar.

 

[Robilious]

Pehaps by now, your problem is solved? However, "flyby54" has the answer. I experienced this on several occasions. In fact, had such a buildup of ink outside of the print area that it was smashing blankets!! Changed to 3 different fountain solutions over 2 days!!! Couldn't solve it!!!???

Turns out, Plate Processor Technician was in and changed the thru-put speed of the plate processor!? So, to be clear: The visible image you see on a printing plate (with some exceptions) is only a dye. This dye is there to enable you to see the image on the plate. The actual plate emulsion is in fact invisible to the naked eye. So, even though the plate developer was removing this dye component, it WAS NOT properly developing the plate!! The image area appears visibly clean, but it is still quite ink receptive!!

So, Press Operator (innocently) ups the water to get rid of any residual toning. However, the fount pushes this residual ink off of the printed image area and on to the outside edges of the blanket. (because running a smaller sheet size, paper doesnt take it away)

Therefore, this is actually a problem with proper plate development!! You can test this by taking a freshly developed printing plate. (If CTP, make sure it is unbaked) Wash off the plate gum or finnisher with warm water. Pour some acetone in a non-image area and let it sit for 10 minutes. If a visible ring appears, then you actually have an under developed printing plate. Need to consult your plate manufacturer and get them to check your plate processor!! ;-)