Switching jobs Uncoated>Coated or Uncoated/ back side sulfate board

Discussion in 'Komori Printing Presses' started by spoonder, Oct 11, 2011.

  1. spoonder

    spoonder Member

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    Hey guys,

    I am working with a Komori Lithrone 529. It runs very well when i switch between coated jobs.

    But unfortunately when i want to switch between jobs from Uncoated>Coated. The density is always to high and black is ridiculous higher about 0,40 in targets.

    Got a few options but i don know what is the best way to reduce install paper.

    I can wash my inkt-rolls. But my doctor-blades are so tiny. That i need to clean them more then 1 times a week. Mayby even 3 times.

    Or i make a few prints without dampening. But then i lose to mutch inkt.

    How do you guys work with this circumstances?

    Regards,
     
  2. Meny

    Meny Senior Member

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    Why not simply De-Ink at the end of the job ?
    then you get a thin film of ink on your rollers and once you pre-ink to the next job with the right profile you should be OK....
     
  3. spoonder

    spoonder Member

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    I always de-ink on the end of the job. About 14 sheets. And 26 sheet to clean the blancets. But that is still not enough. P4 inkt back works not That fine.
     
  4. spoonder

    spoonder Member

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    We use deep black by the way
     
  5. Meny

    Meny Senior Member

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    settings

    check your settings
    could be that by changing youe settings you will get a better result
    once you de-ink you take the ink off the rollers and the blankets , so you should not have too much on the ink train once you re-start the next job unless you pre-ink too high
    I wonder what do Heidelberg users say about this... :)
     
  6. Kaoticor

    Kaoticor Senior Member

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    We have the same problem on our Lithrone 28.

    We turn the ductor off with a few hundred sheets to go and then, on the coated side, we start off running with the ductor off untill the black levels out. We could wash down if we wanted to really cut waste, but the time is more important for us. Although, if anyone presents a better idea, I am all ears!
     
  7. petar

    petar Member

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    Maybe you have to try after you de-ink not to pre-ink the black unit. If you still have a lot of ink increase the number of sheets for de-inking. And for Meny, I,m Heidelberg user and I don't have such problem on my press.It's a simple settings no matter Heidelberg or Komori.
     
  8. spoonder

    spoonder Member

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    I can try to set the de-inking number on 40. And copy the coated KMS profile. And change the pre inking to 0 for black And 1 for c/m/y. Gonna try this tommorow.
     
  9. William Taylor

    William Taylor Senior Member

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    You are going to run probably 25% more ink on an uncoated sheet.
    When you switch jobs then run 250 sheets of waste stock through the press until your profile is close.
    Otherwise turn your ink vibrator roller off and run 50 sheets to bring your ink down.
     

  10. spoonder

    spoonder Member

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    well i have tried a lot of ways. And it is just a problem that not easily can be fixed. What i now do. Is make 15 sheets whit de-inking slowly. Without damp.
    15 sheet for Black. And 5 sheets de-inking for cyan/magenta/yellow. All without damp off.

    After that i trow a P4 after the first measure. And i don't send the measure to the pqc.