Flexo

[Stiv]

I need a crash course in Flexo as it relates to prepress.
Anyone have or know a good place to start?

[DigiCorn]

I thought Flexo was Bender's evil twin on Futurama. But since Bender is already evil, Flexo is actually good. You can tell, because as we all know from Star Trek, evil twins have a Van Dyke.

[David]

what about flexo do you need to know?
We make a few flexo plates here with the Kodak Flexcell system.

[Stiv]

what about flexo do you need to know?
We make a few flexo plates here with the Kodak Flexcell system.

Do you treat it as another job and just output it differently? Are there special trap settings? What's this about the yellow stretch?
Do you run film and then expose to a rubber plate? How does that work? Anything special?

[beck]

what about flexo do you need to know?
We make a few flexo plates here with the Kodak Flexcell system.

Do you treat it as another job and just output it differently? Are there special trap settings? What's this about the yellow stretch?
Do you run film and then expose to a rubber plate? How does that work? Anything special?

We print lot's of Flexo here.

We prep the art, do the Flexo Layouts, have plates made outside.

 A few things are...

More trap (.008 to .010, depending on the job), gradients (don't drop to a 0% dot, stay at least 2%), watch reversed type on multi-color backgrounds.  Register usually isn't as tight as Offset.

Any specific questions, ask.

beck

[DigitalCrapShoveler]

And distortion... don't forget the distortion.

[andyfest]

Flexo screens and screen angles are different than those of offset as well so you should check with your RIP support group re: requirements. I know that every Esko seminar we have been at, they have separate sessions for offset and flexo as there are very few common requirements in setup between the two types of printing.

[David]

Flexo is a different animal when it comes to 4c, screening and content.
We make our flexo plates in house using the Kodak Flexcel. It's a digital/analog workflow.
We send a 1 bit tiff to our Evo box, it gets ripped and output as film on our Trendsetter.
The file is then placed on top of the polymer flexo plate and exposed in a vacuum frame with UV lamps.
It is then run through a processor (serious scrubber, killer solvents) and then "cured" (we use a 30 min Turbo dryer, and then the plate is further cured with UV A and UV C lamps).
After the plate is cured, it is mounted to a hard plastic carrier with double stick tape which is then mounted on our Offset UV press.
We have different tapes for different types of images, vector images can take a stiffer, harder tape whereas screen images (maybe with vignetted edges or gradients) will use a softer more squishy tape (yeah, a real technical term, for sure).
The main exposure of the plate can also be varied (depending on the image type) for even more control of the dot shape and what we want to hold on press. We also can vary the back exposure to help with the height of the shoulder of the dot shape.
We can also use different screening on them, from 300 line, or stochastic, or even as low as 33-50 line. Depends on the project and what we're trying to achieve on press.
And depending on the press, we change the distortion as well.

We can make sheetfed flexo plates as well as metal backed Skor plates for the Web press.

We be bad.

[Stiv]

Thanks, that's exactly what I needed.  :smiley:

[beck]

http://www.flexography.org/edutrain/first.cfm

Here's a link to a pretty good Flexo site.  We bought their hardcover book many years ago (12+ years ago), and it was really helpful when we were getting started in Flexo.

They now have a downloadable PDF.  I glanced thru it just now (no time to really read it).  Looks to be pretty decent, especially for those new to Flexo.

beck

EDIT:  Just took a little longer look.  It's more for designers than for printers.  You might find some useful info, though.

[Stiv]

Oh yea, great linky. Thanks.