UV Ink Piling on the proceeding units (heidelberg)

Can anyone tell me what cause UV ink to pile on the impression cylinder of the procedding units ? is it ink water balance ? Thank you

 

Hello Raymond
One thing I can say from running uv om a royal zenith planeta 40inch perfector with grafix uv system in units 1-2-3-4- skip 5 and a double lamp in 6 for the uv coating.Yes it could be ink and water balance.Very fine line i tried to run as little water and ink as possible.Also could be ink, you may need a little more photo inishiator in the ink(dryer) consult your ink vendor . one more thing make sure you have the back pressure right on the printing units.
steve

 

ink piling

Thanks Steve I will look into that.

 

I too run all UV ink I run a speedmaster cd 102 6 color and we change our uv lamps every 3 months but we should change them every month, but yes it sounds like Steve it right on the money we to had that same problem with using sun chemical ink we had to order a pal of that photo inhibitor

 

Hello

try to change under pack for blanket to the same size like the printed sheet.

 

I ran a 6 color Roland with U.V.... Like Racer said, my bet would be the photo inishiator in the ink. Have your ink sales man spend a couple hours with u watching the press and seeing what the ink is doing. Our ink salesman came out one morning and worked with us from 4am to noon so he could get a better idea of what was going on. If he doesnt want to help you, then try another ink company...

 

Raymond, It doesn't say whether or not you are interstation curing. If you are it can be an partial cure of the ink film. This causes it to get just tacky enough to pull off on the subsequent units impression. First ensure you are running as dry as possible, also ensure that the ink is strong enough and your not having to push that color. Next verify that the ink is not emulsifying, pressure and packing are proper and the color rotation is correct for that inks coverage. In some instances it makes sense to wet trap the colors rather than inter-station cure them. Not only does it save you from this type of aggravation it also saves a lot of energy. You can add photo to most formulas, but sometimes cutting a little press speed can cure this issue as well. Not ideal just an idea. Good luck.

 

thats cheating

 

UV piling

I run a Heidelberg cd74 6/C UV with IST lights and we print on plastic.
I found that the type of blanket has alot to due with the pile issues (release) we have tried just about every blanket on the market and found a UV blanket made by bottcher, it's a purple semi compressible.
Substrate, ink, amount of energy, light configuration, black first or last, too much alcohol sub (water mix, run as lean as you can in your mix) It's hard to pin point the exact problem without knowing what your setup is. Photo initiator is just a band-aid to the real issue at hand.

 

Oops

Sorry about that last post, i had it in my head that you had pile issues on your blankets not your back cylinder.

 

I have not found an easy answer to this situation we have this problem as well however we call it picking off downstream. Obviously the ink and water balance must be as dry as possible if you have the option of using alcohol this will help with the release by lowering the surface tension. Additionally it is somewhat unorthodox but find the unit that the ink is picking in and turn the water up this will lower the surface tension as well and provide quicker release. DYC blankets formerly K110 now called Jupiter

 

I understand what you are saying about the lamp changes as we do this about every 6 months but monthly seems unusual and quite costly unless you are only wet trapping and curing in the delivery

 

Was running uv on cd 74 with toyo ink 1lamp on yellow unit #5 the yellow ink would constantly dry hard on back cylinder \ and would dry up on the edges of sheets I felt the lamp was installed to close to bottom cylinder, the excess heat making water balance a nightmare,we were always trimming packing and blankets,some crazy **** when you have to do that,ran regular ink for 30 years never had to do that, hopefully by sharing our insights we can help some other guys from going crazy,

 

Where is it piling on the imp cylinder, are you drying on each unit? Do you cut packing for the sheet size.

 

Yes we had pre cut packing for 23x29. /19,x25 ect. This helps but not a cure all

 

But it was mostly the yellow unit.and I felt the uv lamp was installed to close to the bottom cylinder it was hot / so you had to bump water up

 

We cut our packing to size on every job but we run board stock .013 and up very rarely do we run thin stock. We do get some piling on op white and a few other color but cutting the packing to exact size or just a bit bigger helps alot. You can try using more photo Initiator.