Micro Flute CMYK issues

[BeezaJoe]

Hi, just wondered if anyone has come across this problem.
We are having consistency problems when litho printing CMYK jobs on N Flute board.
Most of the time its fine but the cyan in particular does not cover well and gives patchy results.
The board supplier says its just one of those things that they can't explain.
We have tried different blankets, and different tension on the blankets, varied the impression etc
but we still get the same problem. We are now running this particular job using a spot colour
and it covers perfectly.
Any thoughts would be appreciated. Thanks

 

[gordo]

Hi, just wondered if anyone has come across this problem.
We are having consistency problems when litho printing CMYK jobs on N Flute board.
Most of the time its fine but the cyan in particular does not cover well and gives patchy results.
The board supplier says its just one of those things that they can't explain.
We have tried different blankets, and different tension on the blankets, varied the impression etc
but we still get the same problem. We are now running this particular job using a spot colour
and it covers perfectly.
Any thoughts would be appreciated. Thanks

Have you tried switching the M and C units?

 

[BeezaJoe]

Morning Gordo, no, haven't tried swapping units. We normally run with KCMY. Switching off the K, M and Y units still gives the fault on the Cyan.
The Board rep says its a problem with micro flute and Cyan ink. We are going to try another Cyan, but I wondered if maybe a larger screen size might make a difference . . .

 

[gordo]

Morning Gordo, no, haven't tried swapping units. We normally run with KCMY. Switching off the K, M and Y units still gives the fault on the Cyan.
The Board rep says its a problem with micro flute and Cyan ink. We are going to try another Cyan, but I wondered if maybe a larger screen size might make a difference . . .

The notion of switching the C and M units was to rule out a press unit mechanical issue. I.e. if you changed the rotation and now the M is a problem then that rules out the ink as the source. It is possible that going to a coarser screen might reduce the visibility of the problem - but IMHO it doesn't solve it. What does your ink vendor think? Usually if it's an ink substrate issue then sometimes you'll see the problem to some degree with the other 3 inks.

 

[Alois Senefelder]

Mottle ??

Have you tried running trial 1,000 sheets of N-Flute Board from a different manufacturer, without changing anything printwise ????????

Regards, Alois

 

[RJ Litho]

What blankets are you running? Conti makes a blanket specifically for fluted board .We are running 200 LPI on all n flute work . Lower tack on second ink depending if it is cyan or magenta .One thing you can try is move Cyan further down one full unit away this will help with lay down. The blanket helps in filling many of the highs and lows of the stock .Hope this helps
Bob M