Coater blanket

Discussion in 'Heidelberg Printing Presses' started by Drbevan, Jun 24, 2015.

  1. Drbevan

    Drbevan Member

    Joined:
    Jul 2011
    Messages:
    30
    Location:
    Perth, Australia
    Hi All,
    can anyone shed light on why the coater blanket on XL75 picks up quite a lot of ink. We run with medium weight anilox an have the pressure backed of until just kissing, ink is building up and we get 2 heavy horizontal strips that are thick.
    Any ideas are appreciated.
     
  2. boooch

    boooch New Member

    Joined:
    Aug 2014
    Messages:
    2
    Location:
    Russia
    Hi! You can pictures to post? What anilox you have?
     
  3. Jruff

    Jruff Member

    Joined:
    May 2014
    Messages:
    13
    Location:
    New Jersey
    Sometimes we experience that if there is a light film of coating on the blanket while there's a lot of ink coverage on the job. Increasing the flow of coating % usually alleviates the issue.
     
  4. mrheidelberg

    mrheidelberg Senior Member

    Joined:
    Jan 2008
    Messages:
    648
    Location:
    United Kingdom
    That cannot be done on an anilox roller equipped machine, the only way to increase / decrease the coating is to change the actual anilox roller.
     
  5. turbotom1052

    turbotom1052 Senior Member

    Joined:
    Oct 2008
    Messages:
    826
    Location:
    Vermont
    do you monitor the flow of your coating with a Zahn cup before pumping it up to your coater? Id begin with that and then if the problem persists id be looking at your annilox roller for clogged cells and also if its the right roller for what your trying to do.
     
  6. aqazi81

    aqazi81 Senior Member

    Joined:
    Oct 2009
    Messages:
    821
    Location:
    KARACHI PAKISTAN
    Few possible causes...

    Coater activating late, allowing ink to transfer to
    coating blanket at start-up.
    • Excessive pressure between blanket roll and
    impression roll causing squeeze out of coating
    and pick up of ink on blanket
    • Insufficient amount of coating being carried by
    blanket.
    • Ink volume too great for single station
    application or to allow sufficient bodying before
    coating application.
    • Ink tack too low, producing a weak strength ink
    film.
    • Excessive water pick up from fountain solution
    by ink causing extended open time and ink film
    weakness.
    • Coating not rewetting properly.
    • Blanket too soft or tacky due to having been
    washed repeatedly with petroleum solvent.
    • Improper blanket cleaning or possible
    contamination.
     
  7. Ade

    Ade Member

    Joined:
    Dec 2013
    Messages:
    32
    Location:
    N/A
    Yes I would agree with that
    If you are backing the pressure off the blanket to impression cylinder,
    are you setting the pressure of the anilox roller to blanket?
    is the under packing correct, is the blanket thickness correct?
    if you are using under blankets is it fitted correctly should be white side up black to impression cylinder,
    what consumables are you using? cheap blankets and coating may be causing your problem.
    are you using the clean off facility at the end of the run?
    is the anilox roller clean how often do you send it away for cleaning?
     
  8. Drbevan

    Drbevan Member

    Joined:
    Jul 2011
    Messages:
    30
    Location:
    Perth, Australia
    Thanks for all the help, will investigate the possibilities.
    Regards.
     
  9. drayprintman

    drayprintman Member

    Joined:
    Jun 2015
    Messages:
    5
    Location:
    15,olarewaju street orile agege,lagos state nigeri
    if the suction pipe is not sucking the coating well or the coating have finish
     
  10. Ade

    Ade Member

    Joined:
    Dec 2013
    Messages:
    32
    Location:
    N/A
    Just a thought it is some thing we had a long time ago have you changed the Anilox roller?
    If you have you gone from light roller to a solid roller the bearings may not be designed for the solid roller as it is heavier and can cause some wear which could show up as some ovulation which could possibly show up as lines on the blanket?

    just thought!
     

  11. Drbevan

    Drbevan Member

    Joined:
    Jul 2011
    Messages:
    30
    Location:
    Perth, Australia
    Thanks Ade.
     
Loading...