ink feedback on water rollers

Discussion in 'Web-Presses' started by pa printer 3, Nov 17, 2009.

  1. pa printer 3

    pa printer 3 Member

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    Location:
    pennsylvania
    I run a 4 color Solna heat set web and I have a serious issue. I am getting a lot of rollback or feedback of ink onto my water feed rollers.
    I run a onestep fountain solution with a 4.0 ph, I have conventional water system and the feed roller is covered with a paper sleeve.

    If Marcus answere this I see he runs a Solna web same era as this one, I have thought about dropping out one of the ink form rollers ( we have 3) any input from anyone would be a great help.
     
  2. nosefo

    nosefo Member

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    Ink-feedback to much water can be the reason

    We have a 9 color narrow web press with "conventional" dampening system. (pool roller - chrome roller stacked on top of this) ink/water roller againt the plate. We use UV color only. And we have from time to time the same struggle but we can avoid this by doing this...... My experience is 15 years of printing on multicolor presses.

    I have reason to belive that you are running with to much water......?
    To much water in the ink make the ink hydrofile "water friendly" and then you will experience problems like yours. The color will be transported back to the dampening system and you will have a problem.
    If you have to much water mixed into the color you can sometimes see this on the roller located closest to the dampening system, your rollers have a "orange skin" look. I you see this symptom "orange skin ink", the solution is very simple. Reduce the water.

    My second thought is that you mayby run the machine with to much opening between the pool roller and the chrome roller, instead running with a "tight" setup and increase the speed of the dampening system instead. :)
    You may have to increase the level of IPA to keep your plate clean, but you will at least have a clean pool roller. When reducing the amount of water you will also reduce the chance for dust pickup on the blanket.
     
  3. pa printer 3

    pa printer 3 Member

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    Finally some help.....Now you say orange skin look, as in a mottle or emulsified ink?? We do get a bit of emulsified ink but mostly on the ends of ink rollers. It is curious you say to much water because when we look over the plates they are a dull not shiny appearence to them when we are running. My second question is referring to " to much space" . You mean a tighter roller to roller setting and ramp up the water feed also you say add more alcohol and I do believe there in lies some of our problem our supervisor does not have us on alcohol , says we can run conventional without it, but I doubt we ever will and now with this I have an opinion from outside source......thanks a bunch for reply.
     
  4. nosefo

    nosefo Member

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    I know why you are struggling with to much water on the edges

    If you can send me and e-mail at morten#aske.no I will send you a drawing with a description what causes this.
     
  5. pa printer 3

    pa printer 3 Member

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    I tried getting an email to you but it is not formatted correctly.....morten#aske.no is what I typed in but would not go.
     

  6. nosefo

    nosefo Member

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    I have used the # symbol in the place for the @. The reason I do it like this are to avoid net scanning after e-mail adresses, with the result of full inbox of spam mails in the future. So please try again just swop the # with and @ and you will suceed.
     
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