flourescent ink printing on uncoated stock

Discussion in 'Heidelberg Printing Presses' started by allyb, Jan 27, 2012.

  1. allyb

    allyb Member

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    Anybody out their with any suggestions how to counter a mottling effect when we print using a flourescent ink on uncoated stocks, have had the same issue on varying grades of substrate, tried 2 brands of ink, on 2 presses, CD74 AND SM52. New blankets, ink/fount balance, all the usual checks.
    Am testing again on Monday, different higher grade stocks with smoother surfaces and a bit more squeeze.
    Really frustrating as we have previously printed copies from previous printers which look lovely and flat, and we need to match.
    Our presses are in good order new rollers/damping etc. and branded chemicals etc.
    Lots of head scratching here!!!!!!!!!!!!?????????????:confused:
     
  2. HPC

    HPC Senior Member

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    Maybe your presses are too good. I am not saying that to be a smart @ss. We run flood coating on a flourescent ink with nice coverage and an even coat on uncoated stock. We are a business forms printer, half web presses. Only trick we use is screening it 90% and letting the press gain enough dot to fill it in making it look solid. Presses run with a 3 ply compressable blanket, and as you can tell, a lot of dot gain. Hope this helps. Has the pressroom tried cutting the keys way back and maxing out your sweep??
     
  3. allyb

    allyb Member

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    Hi HPC,
    Thanks for your reply, will try the 90% hit, as for the duct sweep and opening keys, we find flourescant does require a fairly high level of ink thru' the roller chain, and not sure whether this is could be a possible factor?
    Thanks again.
     
  4. HPC

    HPC Senior Member

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    Your welcome. Your running some pretty nice iron so I don't think the ink train is a factor. But in case it is, getting the keys as low as possible and increasing your sweep, will make the ink fountain roller act as part of the ink train, so when the ductor comes around its not laying a big glob into the ink train. This always helps us.
     
  5. allyb

    allyb Member

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    Thanks again, will explore any ideas, check out our website might give you some idea of the work we produce and our strive for quality.
     
    Last edited: Jan 30, 2012
  6. FSA

    FSA Senior Member

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    allyb
    I run 805 regularly and for us to get a smoooth solid we use unit 1 for dusting, unit 2 for a 25% screen, unit 3 for a 65% screen, and finally a100% on the fourth. This is printed on the back side of a number two card stock(The cheap stuff). We are do this job on a 3304 with FM screening. Let dry for a few day then go back and hit the black & blue, black is done as a overprint, the blue is fitted into knockouts.
    FSA
     
  7. Grant B

    Grant B Senior Member

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    I would suggest running the flourescent in your last unit. We've had the same problems with PMS colours on uncoated stocks. Every blanket the sheet comes in contact with after being hit with the flourescent will worsen the motley effect. Good luck.
     
  8. FSA

    FSA Senior Member

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    allyb
    Question, how many units do you have to work with? Really you do have a whole host of problem if all those machines can't match another press in a different shop. As a operator that prints in many shops every week now for allmost 15 years, and can't stress enough that the machine is only as good as the operator !
    sorry FSA
     

  9. turbotom1052

    turbotom1052 Senior Member

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    ive found dayglow inks to be pretty weak. Seems like your always pushing huge amounts of ink in order to match the pms book Id suggest you try splitting the task between 2 units. Ill bet a double hit will print a bit smoother as long as you reduce the 2nd hit a bit in order to get it to trap properly
     
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