Doubling problem?

Discussion in 'Heidelberg Printing Presses' started by Greg Wallace, Oct 13, 2022.

  1. Greg Wallace

    Greg Wallace Member

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    I am running an SM52.
    Running 1 unit, I am getting what I think is doubling.
    At first look it looks like the ink is contaminated from a drip of washup solvent from the drip tray.
    I tried running low ink and high water to see if the reverses clean up. Just makes it worse.
    A preliminary check of most all roller stripes looks good.
    I have run this blanket for a long time, but for the blanket to go bad in one day seems odd.
    All water and ink settings are at normal levels. No toning on the sheet, no washed out areas.
    Tried different ins and ink colors.

    Any ideas before I tear it down and start from scratch?
     
  2. Michael Lee

    Michael Lee Member

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    if you input "double image" in search, you can get plenty of answers.
     
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  3. Jack liston

    Jack liston Senior Member

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    Try to lower water and ink use 1st unit to smooth sheet put on impression. Also try a different type of stock.
     
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  4. Greg Wallace

    Greg Wallace Member

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    Yes, of course. I did, but most all of the suggestions were related to printing unit to unit. I'm only using one unit.
    Thanks for the reply, though :)
     
  5. Mechanica Speedmaster

    Mechanica Speedmaster Member

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    Hi Greg,
    i realy dont understand your matter, how can you have doubling printing on one PU? Can you describe a bit more what is wrong with your print, give me infos about color allocations and between which PU-s you have problem. Its also important to explain me in which direction you see the anomaly (circumferential or side), whole image affected or only on front or rear edge, etc...?
     
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  6. Beguin

    Beguin Senior Member

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    Hello dear sir, could you please show us the pictures in question?
     
  7. NotAGooner

    NotAGooner Senior Member

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    Loose blanket?
     
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  8. Adil

    Adil Senior Member

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    Please send me a picture to see very well what happends ???
     
  9. Greg Wallace

    Greg Wallace Member

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    you are correct. I misspoke. It's not really doubling, more like a halo effect. the second photo is my previous run.
    It's hard to see, but it's there.
     

    Attached Files:

  10. Adil

    Adil Senior Member

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    Hi sir
    this one is not a dubbing, it seems that it is a bad development of the plate also check the date of perumption of the plates. Convernant the wetting solution must respect the standards, ph between 4.8 and 5.5 conductivity between 1300 microsimens and 2500 ipa between 8 and 10%.
    these two factors can cause problems the quality of the plates and the development on the one hand the standard wetting solution on the other hand
     
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  11. Greg Wallace

    Greg Wallace Member

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    I believe you were correct, sir.
    After pulling and checking and re-setting all rollers the print did get a little more open in the reverse lines. I rechecked my EC and it was very low.
    I normally only add 4 oz/gal fountain solution as my water from the tap is very high EC. I added more than the maximum recommended 6 oz/gal fountain solution and that pretty much cleared everything up.
    Thank you for you time and advice.
     
  12. Adil

    Adil Senior Member

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    Contact me via whatsapp i will send you a very good document of impression problèm ,
    +212700552467
     
  13. turbotom1052

    turbotom1052 Senior Member

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    what Im seeing looks like it could be slapping. Are you running a super blue or a transfer jacket? If its super blue you may want to either change it for a new one or brush off the ones that are on there already. Also check the tension of super blue if so equipped. If its a transfer jacket you may want to try cleaning and adjusting the jacket or perhaps even prop the sheet off the jacket with either some weatherstripping bumpers, or velcro bumpers. If the press is equipped with a segmented skeleton drum you may want to remove or move different segments to support sheet travel without marking.
     
  14. Greg Wallace

    Greg Wallace Member

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    So.... In the end I think it was my water the whole time. I cleaned and adjusted everything from scratch. It got a little better, but changing to distilled water really made the difference.
     
  15. Adil

    Adil Senior Member

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    Hi sir
    The conductivity of the water is a very interesting factor, even if you respect the fundamental percentage of the additive and the ipa if the starting valeur of your tap water is not good the solution will not be ideal. So always check the hardness of tap water and its conductivity before adding additives and IPA. In fact there is a difference between distilled water and osmosis water because distilled water can damage the pipes of the players if you have the thermoregulation system by tearing the material. Reverse osmosis water is water that contains minerals and especially iron so it does not tear the iron molecules in the piping
    Good luck
    +212700552467
     
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  16. Greg Wallace

    Greg Wallace Member

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    Thank you for the advice.
     

  17. Adil

    Adil Senior Member

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    be welcome
     
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