Adast 313 Gear Streaks on Blanket

Discussion in '1-Color and 2-Color Offset Presses' started by demel, Jul 1, 2008.

  1. mrheidelberg

    mrheidelberg Senior Member

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    Hi,

    Try a new blanket with a quick release property like one called Perfect Dot.

    Regards.
     
  2. demel

    demel Senior Member

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    Dear Somma,

    Still couldn't find a time to uncouple the inking system as you suggest
    since i am on a busy schedule.......I have no words to thank you coz
    you directed me to think different way....
    it brought me to a new area of the technical side of this machine.....
    actually i learned a lot from your every reply.......

    Thanks for you too dear mrheidelberg for the blanket suggetion.


    Once again thank you so much for you both.....

    I'll come back with result soon ....


    regards,

    demel
     
  3. demel

    demel Senior Member

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    Hi Dear Somma,

    I am back......

    So sorry to tell you that i found nothing by replacing the blanket with
    a new one.....still the streaks exists....

    I think only remedy is to uncouple the ink system and see as you said earlier.
    but it's a time consuming work....that's why i am trying all the other things before heading to that step....

    is it possible to happen this kind of streak problem due to worn off bearing attached to the form rollers.

    Please help....

    Thanks,

    De Mel
     
  4. demel

    demel Senior Member

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    dear friends,

    Still couldn't resolve the streak problem on the blanket....
    can anyone suggest me something to give a try....

    Thanks in advance,

    de mel
     
  5. somma

    somma Member

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    Dear Demel:

    Please take off all the plastic gears, may be it will take time, but when you are having a strange problem and you need take all the posible way to find the problem.

    I not sure if you change the blanket the problem desapair, but change it is not a bad idea.

    Please give a update.

    Good luck
     
  6. demel

    demel Senior Member

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    Hi dear Miguel,

    Hey! Buddy you are back.....
    I am so happy about that. i'll give a try now.
    i think there is no any other options remaining to go.

    Thank you so much for encouraging me to go to that step.
    I'll give you and update soon after the trial.

    Thanks,

    demel
     
  7. demel

    demel Senior Member

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    Dear Miguel,

    Here is the update....

    First i uncouple the ink system and tried.
    removed all the plastic rollers attached to ink system.
    but there were no indication of reducing the streaks,

    then I removed all the ink rollers and put one at a time only with a
    rilsan rollers.....i did this for all 3 form rollers separately.
    from this method i was able to find non of the rilsan rollers responsible
    for this streaks....the problem still there. all the streaks
    are coming from the same place at every time.

    when i did the above i removed all the dampening rollers to plate.
    i took a solid to plate.....the whole solid came with gear streaks that
    i am referring is can easily be visible on the plate....
    i think you also told this thing earlier that the streaks should be there
    on the plate before it comes to the blanket.

    But, when i loose the chain in the delivery unit to some extent....
    say about 1.5 cm then the streak goes away only on the
    tail half of the plate. the delivery chain setting was little tighter.
    i had to tight it coz there were some paper jamming problems due to it
    looseness.....

    Now what do you suggest to do???
    the half of the streaks has gone away on the blanket.
    but the most important front half is still there.

    Please help.....?????


    Thanks

    de mel
     
  8. demel

    demel Senior Member

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    is it a cylinder bearing problem....???
    any one have previous experience like this.

    Thanks,

    demel
     
  9. somma

    somma Member

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    Hi demel

    Thanks fot your update.
    Could you explain again what you did with the chain delivery thats the streaks gone away?

    regards.
     
  10. demel

    demel Senior Member

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    Dear Miguel,

    Here is the setting i did...you can get a clear idea about what i did
    from the attached.....and also i would say you this thing also...
    There is medium tightness between the CP cylinder and the Chain Delivery wheel when i am rotating the machine by hand.....it stuck in the one position of the wheel when i am rotating and then the streaky and shaky feeling comes to my hand. i think it's very similar to final Streaky out put.there is no smooth feeling at all...

    But, when i take a close look at the gear teeth on the three cylinders
    there is no worn of problem.

    Sorry for bothering you......Please help if possible.

    Thanks,

    demel
     
    Last edited: Jan 10, 2009
  11. demel

    demel Senior Member

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    Dear Miguel,

    I am so sorry to inform you that the problem on the whole
    plate still exist. today i tried another solid after removing
    the dampeners. but the streaks still there.this time it came
    even after loosening the chain delivery setting. no luck....!!!

    I think this problems came after replacing the all form rollers
    and other inking rollers of the machine. it seems like
    the hardness of the rubber is responsible for this streaky problem..
    i think the replaced locally made rollers are not up to
    the standard that machine wants. they are too hard when touched.

    any one have experience like this due to too much of rubber hardness.

    awaiting for your reply...


    demel
     
  12. somma

    somma Member

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    Hi Demel:

    I have read about hardnees roller in my handbook machine and is 25 shore.

    regards
     
  13. demel

    demel Senior Member

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    thank so much Somma for helping me to find out every possible way you could...

    according to my roll manufacturer its around 30-35... is it too high...?
     
  14. mrheidelberg

    mrheidelberg Senior Member

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    30 - 35 could be too hard. Do you have access to a shore hardness meter to check the rollers yourself. Can you get Bottcher rollers in Sri Lanka.

    Regards.
     
  15. demel

    demel Senior Member

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    Dear Sir mrheidelberg,

    Thank you very much for your quick response.

    I am sorry i dont have access to that kind of expensive shore hardness meter.
    thanks to your bottcher suggestion i just surfed through their
    web site. it's amazing. it's a good source for rollers related problems.
    i learnt a lot from their site. Thank you sir for quoting that name.

    I dont think i could find the bottcher rollers here.
    but i am gonna give it a try.

    i found a another roller manufacturer who maintain the shore value
    in between 25 - 30. i think this is the best lowest possible value
    we could get from the local roller manufacturer's. what do you think
    about this value...is this also too high for me to go.

    thanks,

    demel
     
  16. demel

    demel Senior Member

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    dont you think this is because of a cylinder bearing issue.
    i think that is the last thing remain to be done.

    feel like move to that step since there is no other option.

    any suggestion...????

    demel
     
  17. somma

    somma Member

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    Dear Demel:

    try to do the following:
    first step, change the bed at the blanket to less thickness to get lower pressure between plate cylinder and blanket cylinder, and see what hapen.

    Check the next,
    -Put the pressure on
    -Block the impression cylinder and blanket cylinder with a reck between the gears
    -Move the plate cylinder back to forward by hand and look if the gear of the blanket cylinder has a gap with the gear of the plate cylinder. If there is the gap between the tooth of gear you can hear a little noise.

    Let me know if you have been this issue.
     
  18. demel

    demel Senior Member

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    Dear Somma,

    Thank you so much for your advice. Again you are pushing me to a new
    location. Actually this is very interesting cos could learn a lot due
    to this problem... Once again thank you so much for allocating your
    valuable time to respond to my postings.


    Here is the update...

    1st - no blanket packing in this machine.

    2nd - I checked as per your directions. Yes there is a play in between
    the teeth of the plate cylinder about .3mm when the pressure is on position.
    Not only the sound, it can be seen very easily. It comes 3/4 of the plate cylinder. in the other 1/4 it comes from the Impression cylinder....

    So...what is the next step i should take....
    Let me know a method to check the blanket to plate pressure...
    then we can check the existing pressure is too low or high..
    i could check this using the ink strip method....is it correct.
    when i checked, the thickness of the strip is around 5-6mm.

    Awaiting for your guidance.

    Thanks & Regards,

    demel
     
  19. somma

    somma Member

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    Dear Demel:

    This is not a easy problem.
    The "play" that you saw is not too much
    Try to do this: Put a little "heavy" grease on main gears, Why I say this, because I am try to fill the "play".
    Other possible way is change the distance between the gears, but to do this you must be careful, If the gears are too close you could lost the JR distance (I wrote about this later).

    regards
     

  20. demel

    demel Senior Member

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    Thanks Somma

    Now i am going to touch the untouched location of the machine.
    i know it is little risky.

    I'll try my best and let you know.

    regards,

    demel
     
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