sheets ripping

Discussion in 'Komori Printing Presses' started by metalheart, Aug 13, 2013.

  1. metalheart

    metalheart Member

    Joined:
    Feb 2013
    Messages:
    11
    Location:
    usa
    We have a LS40. Sheets have gripper marks and are randomly ripping. Does anyone know a good way to locate where the problem is? Ripping seems to go away when running thin stock.
     
  2. Bill Borcicky

    Bill Borcicky Senior Member

    Joined:
    Jul 2012
    Messages:
    214
    Location:
    U.S. Amory, Ms.
    The best way for us to find it was to actually feed stock through the press and as soon as paper started comming out of the delivery, we hit the e-stop. All stock would stop and then we would inch press around slowly, carefully looking at each cylinder's grippers and stock. when you see the torn sheet that indicates the "grippers prior to that unit" had not released the stock in time or you may have a burr on one gripper.. start with the swing gripper and transfer to first unit first. then inch around to next unit. you may have to feed several sheets of stock through the press till you find the correct gripper is found, as you noted it is random.
    ripping going away on thin stock only indicates that the gripper is opening just enough for the thin stock but not open enough for thick stock to release.
    Once you have found the culperate gripper, check to make sure its not gummed up and clean as necessary before making an adjustment. I have seen where a pc of stock just had gotten stuck on the gripper and it did not need adjusted. I also had seen the problem from a wore out gripper, and sticky grippers from water problems earlier in the week....a stopped up drainage tube causing water to overflow, " not a good day for me then".
     
  3. aclockhartnky@aol.com

    aclockhartnky@aol.com Member

    Joined:
    Feb 2010
    Messages:
    25
    Location:
    usa
    Hello Metalheart
    It sounds like your swing grippers are to tight if you are running cover or board stock.

    See Bill's post , He left some great advice.

    Good Luck

    LUCKY-N-KY
    .
     
  4. HANGNBANG_528

    HANGNBANG_528 New Member

    Joined:
    Dec 2013
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    4
    Location:
    california
    It's the gremlins!
     

  5. lwhiskars

    lwhiskars Member

    Joined:
    Jan 2014
    Messages:
    15
    Location:
    spartanburg south carolina usa
    Hello Metalheart,
    Might want to check your delivery gripper bars is the tears on every sheet or every 3rd or 7th? my press has 7 bars in the delivery, you can mark one bar
    and count sheets from the one you marked. One other thing would be to move head stops back to reduce the gripper margin slightly. Good Luck hope this helps.

    L Whiskars
     
    Last edited: Jan 17, 2014
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