Roller marks coming across the sheet for starting few sheets

Discussion in 'Heidelberg Printing Presses' started by Raman karthi, Aug 26, 2022.

  1. Raman karthi

    Raman karthi Senior Member

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    Dear senior members,

    I have the problem in first 2 unit , while printing jobs, from gripper edge above 3 inches distance, there is a roller strip line coming across the sheets for few sheets starting time, I couldn't not find the problem, and while printing, when I see the damper roller,is not rolling smoothly, it's running break up some time while running the machine.please give me the reason why have this problem I have attached the picture.

    Thanks.
     

    Attached Files:

  2. turbotom1052

    turbotom1052 Senior Member

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    Not offering enough information to pinpoint the problem. At a glance it would appear that youve got rollers not making contact somewhere on the press and then when the unit goes on impression and rollers drop a buildup of ink somewhere on the roller train is transferred to the plate in a big blob. This big blob of ink would be too much for the dampener to keep clean.
     
  3. Raman karthi

    Raman karthi Senior Member

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    Dear sir,
    You mean problem from inking unit roller train?
    Should I check inking unit roller contact?
     
  4. turbotom1052

    turbotom1052 Senior Member

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    yes you should begin by checking inker. ALL rollers should be checked. A good indicator of a problem with roller settings would be the way in which the unit washes up. If the unit is slow to wash up and you get lots of skidding of rollers you may have some weak settings or perhaps even no contact at all. Could also be incorrectly installed rollers, or the rollers in the wrong position. If you want to do the job right you should consider removing ALL of the rollers from the unit. Once removed you should inspect them for correct diameter, durometer, and general condition after a thorough scrubbing with some pumice powder and solvent. Then re install or replace if needed, the rollers as per your presses manual. This would also be the time to clean up the side frames of the unit along with the roller cups and hangers. I would say that this procedure should not be rushed through. To dedicate a half a workday to this process wouldn't be unreasonable especially if the rollers are in really bad shape or if the side frames and cups are packed with lots of ink.
     
  5. Raman karthi

    Raman karthi Senior Member

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  6. Raman karthi

    Raman karthi Senior Member

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    Ok sir, thanks for the information, will check the inking roller remove and reinstall
     
  7. Beguin

    Beguin Senior Member

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    hi dear sir, first i would like you to check the contact between the rollers.
    check the contact of the rollers against the plate and the dampening form roller against the plate. check the contact of the dampening form roller against the degreasing roller and see if the movement of the inking form rollers and the movement of the dampening form roller is correct.
    adjusts the contact of the roller against the degreaser and adjusts the contact of the metering roller against the wetting roller and finally.
    Good luck
     
  8. Raman karthi

    Raman karthi Senior Member

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    Dear sir,
    Inking form rollers to the plate looks ok, and for dampening unit, I have checked following order,

    First I removed metering roller out and check dampening form roller against dull chrome roller 5 mm, and checked dampening form roller against plate 4 mm, and then I put metering roller and check to the dampening form roller with ink 6mm, then finally adjust metering roller to Pan roller visual.

    After adjust metering roller to plate damper roller is going more pressure than first check pressure.

    Is it okay, this variation?

    And this order is okay for dampening setting?


    And after checking, while start printing, small time later, dampening form roller is not rolling freely, it is sometimes stop and running then stop and running, not continuous running smoothly
     
  9. Beguin

    Beguin Senior Member

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    hello dear sir could you send a picture of the roller in question? Thanks very much
     
  10. Beguin

    Beguin Senior Member

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    hello dear sir could you send a picture of the roller in question? Thanks very much
     

  11. Adil

    Adil Senior Member

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    Did you solve the problem?
     
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