CD74 after a year why have bearers of blanket and plate cylinders worn?

Discussion in 'Heidelberg Printing Presses' started by hossein, Feb 15, 2017.

  1. hossein

    hossein Member

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    Hi
    Last year I installed a CD74 but after a year I realized that the bearers of blanket and plate cylinders have been worn.
    Can anyone tell me why this happened and what should I do?
     
  2. aqazi81

    aqazi81 Senior Member

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    May be too much impression pressure and for not cleaning the bearers daily. Also if the machine wasn't leveled precisely.
     
  3. hossein

    hossein Member

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    Thank you for your answer. Can you tell me more details if I send you some photos of bearers?
     
  4. mrheidelberg

    mrheidelberg Senior Member

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    How do you know they are worn ?
     
  5. hossein

    hossein Member

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    I checked that.if you have whatsapp I can send photo of bearers
     
  6. mrheidelberg

    mrheidelberg Senior Member

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    Sorry don't do whatsapp.....can you just add a picture on here so other people can see & comment on it.
     
  7. hossein

    hossein Member

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    Here there is a photo of bearer which has been worn
     

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  8. exheidmech

    exheidmech Senior Member

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    While not impossible its very rare to have the bearers actually wear to the point of having print related issues on a CD74. What are you seeing on the sheet? Have you indicated the bearers using a 0.01mm dial indicator or one that is more accurate? Bearer surface is extremely hard and I have seen more often that they crack vs wear.
     
  9. hossein

    hossein Member

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    I see strips on sheet.
     
  10. exheidmech

    exheidmech Senior Member

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    Who has told you that the streaks you are seeing on the sheet is being caused by worn bearers? Streaks are most commonly caused by incorrect plate to blanket pressure, incorrect roller settings or tight gears. Have you checked roller settings? Has anyone tried to adjust plate to blanket pressure? Do you find that you are having to use excessive back cylinder pressure to get the machine to print correctly? Are you using low quality blankets? Roller settings and trying a quicker release blanket are likely the cheapest checks before getting into more costly fixes. I find it unlikely that your steaks are being caused by work bearers.
     
  11. hossein

    hossein Member

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    Bearers of plate and blanket cylinders in each unit have been worn.Can we reduce the pressure on bearers of blanket and plate cylinders or pressure on bearers is fixed?
    Do you know the main reason?or which parts should be checked to find out why they all have been worn?
     
  12. exheidmech

    exheidmech Senior Member

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    Special tool is needed to reset bearer pressure on CD74
     
  13. hossein

    hossein Member

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    Do you have an article Or something else about resetting the pressure on bearers of blanket and plate cylinders?
     
  14. turbotom1052

    turbotom1052 Senior Member

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    Id save the bearer adjustment for someone more qualified even if you had the tool. The fact that the picture you posted that looks normal to me, is seen as a worn bearer, tells me that you're probably not qualified to do the rather intricate adjustment. Not trying to be a dick here just saying.
     
  15. exheidmech

    exheidmech Senior Member

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    The bearer pressure tool used to reset and check pressure is a specialty tool used by Heidelberg technicians. Any attempt to readjust pressure yourself will likely not end well for you. My suggestion is to have a Heidelberg tech come in and evaluate your machine and reset pressure if its needed. I think you will find this is going to give you the results you are looking.
     

  16. hossein

    hossein Member

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    Thank you very much
     
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