Standardizing the process using state-of-the-art anilox technology allows printers to take full advantage of the flexo process.
The channeling effect resulting from the 30-degree geometry allows high-viscosity inks and coatings, such as high-opacity whites, to flow more freely.
Having as many cells as possible under the highlight dots is what will lead to clean and crisp reproduction. To properly support the graphics, a rule of thumb for the required anilox cells per inch (CPI) is five to six times the plate screen. This means that a 300 LPI image will require a 1,500 to 1,800 CPI engraving to properly support the graphic reproduction of a one percent dot.
If this guideline is not followed there is a distinct possibility of some dots being supported and others not. This will lead to inconsistent ink transfer and variations in the highlight and mid-tone reproduction. You will have a very challenging time trying to meet these objectives with engravings that do not offer the uniform construction of one of Mother Nature’s best inventions, the 60 degree hexagonal honeycomb.
High opacity in flexo whites
Mid-volume anilox roller engravings are widely used in both the flexible packaging and UV printing segments to maximize opacity in flexo whites. There are many other variables that contribute to their success like substrate treatment, drying capacity, and plate and tape combinations. But these engravings offer a very cost-effective solution when compared to other forms of printing formats.
In conducting many banded roller trials with numerous geometries and ink suppliers, it has been determined that the 30 degree channeled engraving pattern is most cost-effective with high opacity whites. The opacity readings that were obtained rival any other geometry available. Unlike the standard 60 degree honeycomb geometry, the 30 degree geometry is positioned so the flat is at the top of the cell. Similar to the orientation of a stop sign.
This circumvential alignment of the cells allows us to (somewhat) drag the laser over the top and bottom cell walls to create an hour-glass design of the cell instead of a closed hexagon. This channeling effect allows high-viscosity inks and coatings to flow more freely through the metering blade to reduce the hydraulic force behind the blade and not trap excessive air into the system. This increase in transfer efficiency allows for the ink to wet-out more uniformly thus reducing the effect of mottling or pin-holing. This geometry is very effective for heavy inks and coatings that require mid to higher volumes.