Flexo Screen Angles

[gordo]

Sure sounds like a resolution incompatibility issue - which model ? (link of models below)

Just a thought, is the dpi of the bitmaps the same (or an even multiple) as the dpi of the imaging device? I.e. 2400 dpi in both cases and not something like 2540 in one and 2400 in another.

best gordon p

 

[meddington]

Thought of that. We provided them at 2400 per their specs. I'm told they were imaged at that res, but being removed from the location, I can only take their word...still awaiting print samples.

 

[wesley]

Plates

Plates

Wow, I thought we were the only ones. Something like this happened to us with an older Creo. We would occasionally switch to imaging ultra large film on the device which requires a completely different laser config. When switching back, the exact scenario would occur causing visible patterning in some (not all) screen areas on the plate. The problem was eventually narrowed down to a mechanical problem with the settings change and laser positioning which required disassembly and parts replacement. This misalignment of the head creates strange artifacts in imaging. Those tolerances are fairly, no actually REALLY precise for everything work correctly. It would not happen all the time and after several settings changes it would suddenly work correctly again. Took us a long time to figure it out. Call your service and support to go over the machine.

 

[meddington]

Thanks for the info Wesley, I'll pass that along.
Finally received print samples. Here is a photo of the black sep (printed on poly @ 120lpi, 82 degrees). Does this resemble the issue you described?

 

[gordo]

Finally received print samples. Here is a photo of the black sep (printed on poly @ 120lpi, 82 degrees). Does this resemble the issue you described?

Can you take a photo that's in focus? ;-)

Does the pattern really break up on the left side of the black separation as it appears to or is that a photo problem?

best, gordon p

 

[meddington]

Can you take a photo that's in focus? ;-)

Sorry Ansel Adams, that's the best I could get off my iPhone.

Does the pattern really break up on the left side of the black separation as it appears to or is that a photo problem?

It actually does appear to "break up" along the edges. There's an opaque white underneath the black...its cut back a bit, which shows as the darker "border", but also the white ink coverage is a bit better along the edges and this appears to lessen the issue. Where the white coverage is weaker (everywhere but near the edges in this sample), you can see the pattern from its application with the naked eye...presumably from the anilox as this is solid, not screened. The angle of the anilox appears to be 90 degrees, which would conflict with 82, but I can't imagine it would impart such strong banding given that its white ink. Does that seem far fetched? I do have print samples with much better white ink coverage (no visual pattern seen unaided) and the banding is absent, but these are presumably imaged off their other CDI.

The printer has indicated that there discussions with the CDI technicians are concentrating on the beam configuration conflicting with the 82 degree angle at 2400 or 2450 res.

 

[FlexoGrunt]

Curious, what plate material are they using?
-Thermal, water, or solvent washout?

If there are multiple types in house then perhaps the wrong laser settings are being used?

Does the newer machine have the HD optics whereas the older one is still using the standard resolution?

Do they have a betaflex to actually look at the plate/mask prior to washout?