GTOZ Alcolor dampening probelm

Discussion in 'Heidelberg Printing Presses' started by m_alatorre, Jun 20, 2009.

  1. m_alatorre

    m_alatorre Senior Member

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    Hi everyone,
    I've been here before trying to solve the same problem. We got this new machine and since i've had problems with dampening. The problem basically is that i get more water in the center of the plate than in the edges, so, i use less water=scumming in plate edges. I use more water to clean that=i get too much in center and loose balance there. The problem doesn't present in the exact same location every time so i think its not the rollers(water form and ink form are all new) the specs have been cecked several times and look good. This problem presents in both units. I most say that this problem is a lot greater with high temperaturte(the room is around 90)

    I feel that is't got to be something about water(conductivity, PH, or else) but is seems to be ok for that too.(conductivity was less than 2000) i checked PH and it was 4.

    This is a link for a video of the problem just in case you would like to see how it looks.(my english is not usually that bad, but man, this machine drives me nuts)
    http://www.youtube.com/watch?v=JGFk29rp3lU

    Any ideas?
    thanks
    Moe
     
  2. gazman

    gazman Senior Member

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    Hey there Amigo sounds like you may need an aircon or a de-humidifier.
    As this problem presents on all units its either enviromental or chemistry related.
    Are u running alcohol if yes at what level?
    Also are the new rollers compatible with your current operating parameters e.g alcohol, alcohol reduced or alc free?
    Regards Gazman
     
  3. m_alatorre

    m_alatorre Senior Member

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    Hi gazman,

    I have dehumidifier and we just got AC so room is now 80 but problem persists. I raised water temp to 55 to see if less diference in temp between water and ink-room would make a diference, but it didn't(in fact i think it got worst)

    I use Anchor buffered water additive and alcohol. In winter i can use as little as 2-5% and seems to work most of the times. Right now i'm at 10% and still problems. The other day i went fo 15-18% alcohol and machine started to work almost perfect, but that is just too much alcohol to make it a every-day solution.

    Now that i think about it, we replaced rollers, but they are NOT bottcher. Seller said this rollers work fine with other heidelberg alcolor and other alcohol-based machines but... could it be the rollers? If so, would it be ok to replace only water form and/or water pan or do i need to replace all water AND inking rollers?

    As you can see i'm completly lost here.

    Thanks for your help and waiting to hear your opinions.

    Moe
     
  4. Borut

    Borut Member

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    Hello

    Ph value should be from 4,8 - 5,3 temperatur of water 8-9 celsius

    Regards
     
  5. gazman

    gazman Senior Member

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    Hi Moe
    Could it be that your that your pan rollers are swollen on the ends i guess this could cause uneven ditributoin of water.
    Do you have other presses on premisis that r using the same set-up as this machine ?
     
  6. mrheidelberg

    mrheidelberg Senior Member

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    You can just replace your damper and pan roller.....try and use Bottcher.
     
  7. roland 202 suisse

    roland 202 suisse Member

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    hi! tries to put a bit more pressure between the roller and the dampening roller Chrome (about 1 / 4 turn) and see if it gets better. more pressure will push the water in bords.borut gave you the right information to the pH and 10% alcohol, I also work like that. I hope you understand me, I'm not good at English
     
    Last edited: Jun 24, 2009
  8. m_alatorre

    m_alatorre Senior Member

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    Hi,

    While washing the machine i noticed that ink residue would not flow into washing device in the exact location of the problem. Took all rollers out and found contamination on them(it did not look like regular glaze to me) and gave them a thorough clean. I've changed ink brand and roller wash to see if those were the problem.

    Problem is gone!

    Just a couple of questions:

    1. The actual amount of alcohol i add to my fount is not read by the hydrometer in the same amount. Ex. i add 1/5 gal to a 5 gal tank(10%) and hydrometer reads 4 or 5%. So... Which is the one i should believe?

    2. I started to use bottle water and reduce the amount of fountain solution and now i get vertical lines in my prints. It's like hairs of water that go from the begining of the plate to the end.

    Hydrometer says 4% alcohol and i cant tell Conductivity as my meter has not got here yet(just bought one)
    More fountain solution? More alcohol? Or Less?

    Thank you every one for your time and advice

    Moe
     
  9. gazman

    gazman Senior Member

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    your hydrometer may be out of wack (had that happen to me)
    As for lines check water form for vertical scratches
     
  10. Harry W.

    Harry W. New Member

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    Gents,

    One thing that was not mentioned is the crown of your water pan roller. Also flat spots or low spots will also cause these issues.

    Harry W.
     
  11. Kompac123

    Kompac123 Member

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    Location:
    Somerville, NJ - USA
    Kompac Automatic Dampening System

    Kompac’s range of Automatic Dampening Systems can improve the performance on your press by eliminating the problems inherent in both conventional and alcohol dampening systems. The patented Kompac technology provides the operator with automatic ink/water balance. Kompac
    Automatic Dampeners completely re-balance themselves at each revolution and carry only the amount of ink and water demanded by the image on the plate. Kompac gives instant startup and runs trouble-free – increasing production by 30 minutes per shift. Guaranteed!

    Kompac Automatic Dampening Systems are designed to cut your waste by 50%, Guaranteed...or we’ll take the unit back.

    Features, advantages and benefits:
    • Automatic ink/water balance
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    • ROI of 6 months or less
    And, these systems require no alcohol...ever! That is what makes the
    Kompac Automatic Dampening System the number one dampening system
    in the market today with over 100,000 sold worldwide.
    For more information write to info@kompactech.com or visit www.kompactech.com
     

    Attached Files:

  12. m_alatorre

    m_alatorre Senior Member

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    thanks for all the info!
    I'm just not ready to give up on Alcolor.
    I tried to work with de-integrated water-ink units(that is, with the Z roller disconected) and needed less water to work... but...

    Now i find impossible to find water-ink balance. I get to a point (#3 in potentiometer) where there is too much water(you can see it in the solids) and with the drop of only two 10th(that would be 2.8 in potentiometer) i start to get scumming in the plate. I'm not new to offset printing. Not even new to heidelberg printing. just new to alcolor printing and, by experience, i can tell this behavior can't be normal for a "built with precision, known for reliability" heidelberg press.

    I'm willing to try and diagnose this problem by some experienced operator and/or demostrator over internet video(Skype) if someone feels that's possible and quote a fee for it.


    Thanks again to all
     
  13. printing.hari

    printing.hari Member

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    hi,
    better to check the roller surface properly, or change the roller and try. can u give me some more clear ideas about the problem
     
  14. Mechanic

    Mechanic Senior Member

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    Maybe you have set the metering roller too hard on the water pan roller. Z-roller, is that the indermidate roller you are talking about?
     
  15. m_alatorre

    m_alatorre Senior Member

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    I've tried metering roller at diferent pressures(from 1/4 turn to 1 1/4 turn) with same results. the intermediate roller is the one that can either connect or disconnect water and inking units by means of yellow ink roller.
     
  16. Mechanic

    Mechanic Senior Member

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    Ombre, my question is : by Z-roller, do you mean indermediate roller? Make sure , that your alcohol doser is workink. Get a manual alcohol meter ang make sure that your alcohol percentage is 8-10%. What plate are you running? If you run plates like eg. Presstek you need a lot predampening at every startup, otherwise you get scumming. Try another additive. I prefer Prisco type 3551 plus2 at 7%. If you haven 't set the dampening rollers correctly, dont bother. But I believe that this is the first thing that you did.
     
  17. m_alatorre

    m_alatorre Senior Member

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    By Z roller i mean the roller that touches the water form and can conect also with yellow inking form roller(i guess "intermediate" is the name for that roller, but not sure... would that be the intermediate roller?)

    I'm rigth now at 9% according to our 1/2 year old Royse hidrometer.(i have to add like 11 real percent of alcohol to get that reading) The plate are fine, we run them on our other (non alcolor)presses. My problem is that i can not lower water enough on the plate in order to achieve balance(and a decent print)

    Example: Since the beginning of the run i get a very shinny plate and, as i start to lower water amount, a very rare effect takes place: The layer of water on the plate starts to breake at one or several spots on the plate(it looks very much like the red sea breaking in the"THE TEN COMMANDMENTS" movie) and start scumming there while the rest of the plate remains with excess of water. I looks almost impossible to have scummnig in one inch of the plate and scumming in the very next, but that's exactly what is happening.

    The setting of rollers looks fine:
    water form to water distibutor(matte): 5 mm
    intermediate roller to water form: 2-3 mm
    Metering to water form: 5 mm
    Water form to plate: 3mm

    Thanks for the 1000th time
    Moe
     
  18. Mechanic

    Mechanic Senior Member

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    ΗΑΗΑΗΑΗΑ The ten commandments...Thanks my man!!

    ok.. now..I didnt ask you if your plates are fine . I asked which plate do you use. I have seen a presstek plate running on a GTO 46 with Fleech dampening rollers with tab water and nothing else, but on alcolor you need predampening, like 15 cycles and 10% IPA and 8% additive (prisco that is)for the exact same plate. Your problem seems to be lack of additive. Get a handheld alcometer, the one that looks like a testtube, and get your chemicals right. I nad this problem twice, Once was lack of additive, and the other was lack of alcohol. When its lack of additive , the ph value isn' t wright, (get ph measure strips from your supplier, they are very cheap) and you also see small water lines on your metering roller


    and, YES, that is the indermediate roller.
     
  19. m_alatorre

    m_alatorre Senior Member

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    You're right about plates... I don't know the brand but i know they are filmed in a Bassys print UV setter, Violet plates. They might be agfa, but not sure.

    One thing i do know is that they are very friendly as regards of water reception. I mean that you don need that much of pre-dampening in order to start clean from the beginning, and if it gets dirty, it cleans very fast during run. We also run with Xante polyplates and that's a diferent story. They do need predampening.

    I see those water lines in the metering roller and see the exact same lines in the plates.

    I'm in the process of getting a handheld PH, conductivity tester, but not yet here. I'll get also a alcometer.

    If i go with more water additive... How much more should i use? Right now i use 5 oz (or 145 ml)

    Thanks

    P.D. I want to say that the above movie is one of the best i've ever seen!
     

  20. Mechanic

    Mechanic Senior Member

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    I missed to reply, sorry.I dont know oz I use metrical system. I dont know how big your circulator is , so 145 ml doesnt tell me anything. You need a ph value of 5 to 5,5 max. GET the little measuring strip indicators, that tell you the ph value.
     
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