Emulsion and emulsification

Discussion in 'Heidelberg Printing Presses' started by Raman karthi, May 5, 2022.

  1. Raman karthi

    Raman karthi Member

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    Location:
    nigeria
    Dear senior respected members,

    Please can explain clearly about emulsion and emulsification in offset printing.?
     
  2. Jack liston

    Jack liston Senior Member

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    Connecticut
    Emulsion are used to coat printing plates/ your fountain solution is an emulsion/ Too much solution will break down and emulsify your ink.
     
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  3. turbotom1052

    turbotom1052 Senior Member

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    Vermont
    A stable emulsion in an ink train REQUIRES some fountain solution in the ink rollers. Its when there is too much that rollers become "emulsified" Before retiring about half dozen years ago, I had been noticing a trend with many ink manufacturers that had them formulating their inks with a reduced pigment load. When an inks pigment load is reduced, then you will be required to run a thicker ink film to arrive at the same densitometer readings. As ink film thickness goes up, a number of things happen. Firstly, and perhaps the most pertinent to this discussion, is that the fountain solution delivery will need to be raised. Youve now got more ink on the rollers that require more fountain solution to keep non image areas clean. This scenario can quickly get out of control sorta like a snowball rolling down a hill. The second thing that happens as a result of an inkset having less pigment, is that the thicker ink film will effectively reduce the inks tack. reduced ink tack will result in more dot gain particularly in the mid tones where they have the greatest impact on how we perceive a printed piece. For these reasons you will want to evaluate your ink suppliers formulas when it comes to pigment load. This is one time where you do NOT want to purchase your ink based on price alone. Its the pigment thats the most costly component of an ink. It would stand to reason that in an effort to cut manufacturing costs a reduction in the inks pigment would be a moneysaving option!!!
     
  4. Fawzi_Albasha1

    Fawzi_Albasha1 Member

    Joined:
    Nov 2020
    Messages:
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    Location:
    Amman, Jordan
    I am currently facing an issue where the ink is accumulating on the Water form roller and causing a non-uniform printing.
    I tried to play around with the dampening solution mixture (8%-12% IPA and 2-3% Fountain Solution) and trying three different fountain solutions but nothing seem to show any result.

    Machine: Roland 200
    Rollers: Combi-Rollers (UV and conventional)
    Ink: UV inks

    Do you have any suggestions for this type of issue?
     
  5. turbotom1052

    turbotom1052 Senior Member

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    Location:
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    Is this issue something new??? Can you tie this issue to either a new product that your using, or a new shop procedure? If this is something new then I would be sure that everything goes back to where it was before you encountered the problem if possible. Talk to your suppliers and have them come in to troubleshoot your issues. Begin with your ink supplier. Be sure that your ink supplier hasn't changed the formula for their inks. Chances are if they did they will not reveal that to you, but if they truly didn't, they could offer some suggestions that they will arrive at based upon some specific tests that they can do while in your plant. I would caution you against trying to resolve this issue with dumping a bunch of alcohol into your fountain solution. Too much alchohol will actually create emulsification. Since you mention a buildup of ink on your water form roller I will ask if the press is equipped with an oscillating roller above the water form. Im not much on the newer Rolands but I know that the older Rolands came with a copperized roller that sat on top of the water form and oscillated side to side via a worm drive. Lastly I will say that you have hijacked the original posters thread, and that is in poor form. You really should start your own thread when seeking solutions to a problem.
     
    Last edited: May 10, 2022

  6. Tsvetan Tsaryanski

    Tsvetan Tsaryanski Member

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    Sep 2021
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    Location:
    Bulgaria
    I work on another machine but sometimes I face a similar problem. I clean the roller several times with a plate cleaner until it is fine.
     
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