Anderson offered this answer: “The optimization of plate surface patterning has been a key focus for us since the launch of the FLEXCEL NX System back in 2008. Our first generation of plate surface patterning was designed to improve solid ink density and laydown. It achieved this with a single, regular checkerboard pattern. A combination of ‘islands’ and ‘spaces’ to optimize ink volume and flow. Over time, we developed additional patterns to optimize ink transfer for a range of inks and anilox volumes. Smaller spacing and elements for low-volume aniloxes, and larger spacing and elements for higher volume aniloxes. We’re fortunate to be able to have the flexibility to create and image exactly the surface pattern required for the job, due to the precision and 1:1 image reproduction that’s a fundamental characteristic of the FLEXCEL NX System. It opens up so many possibilities. That capability then allowed us to further develop plate surface patterning to actually combine different patterns on the same dot. We were able to add a small pattern to the edge of elements to help retain the ink within the pattern. We termed this Advanced Edge Definition, and this was the beginning of multi-functional surface patterning, the ability to combine different patterns on a single dot to perform specific functions. PureFlexo Printing takes this concept to a whole new level.”
He explained, “When a plate is under print impression, the ink spread makes dots bigger as physical dot gain. In order to minimize this, we need a way to retain the ink within the pattern, while stopping ink from being pushed over the outer edge of a printing surface. It is essential to get ink to flow around—and not outside—of the plate image, thus minimizing unwanted ink spread. The great news is that we’ve found a way to control this with the use of sophisticated multifunctional surface patterning. It all happens at a microscopic level and involves up to five different functional pattern structures on the surface of a single dot. Considering that a typical 10 percent dot is about 60-μm. to 70-μm., that’s an amazing amount of detail on something that’sonly the width of a human hair.”
Photo courtesy of Miraclon
According to the system’s developer, “It’s the structure of the surface pattern applied in the middle of the print area (dot, line, or solid) that controls density and ink laydown. As you go out to the edges, the outer edge features retain the ink within the pattern when not printing and control the ink flow and unwanted ink spread when under printing impression. It’s a scientific approach to solving the problem but the good news is you don’t need to be a scientist to apply it. We’ve done the intensive work to select, test and deliver the small set of options that will work best in typical wide web production environments.”
The prepress and color management technician’s mission: To select the correct surface pattern from this small set of options to firstly give the best ink laydown and density with the least amount of ink, and secondly the lowest levels of print defects like pinholing, TEV, or dot bridging, for the specific ink/anilox/ tape/substrate combination. This is done at initial setup and locks in that solution along with the dot gain compensation characteristics. Today, 70+ percent of flexible packaging with solvent- based inks can use a single pattern selection for PureFlexo Printing with process inks.
Once selected, the pattern can be applied by a simple digital tag to the file in prepress (preferred) or manually in file selection for plate making. A single sheet of flexographic plate typically will have multiple layouts included to make many individual plates for greater efficiency. Each individual layout can use a different surface pattern, such as for process, spot color and white inks, or can all be the same. The imager just applies the pattern automatically to each 1-bit tiff as part of the imaging process, without loss of speed or productivity.
Efficiency Always
Emma Schlotthauer, chief marketing officer at Miraclon, who served as master of ceremony at the launch, commented: “For brands who rely more than ever on the power of packaging to connect with customers, consistency and eye-catching flexible packaging is increasingly important. Printers need solutions that help meet the ever-expanding demands of graphic reproduction, without needing to operate at less-than-optimum production speeds, or risking press downtime from continual adjustments and unscheduled stoppages.”
She insisted that, “A wide print latitude is the key to profitable production,” then declared, “Addressing a core technical issue— unwanted ink spread–helps to widen print latitude and reset the quality-efficiency balance.”
She professed, “Printers get the best out of their press machinery when they have the flexibility to run uninterrupted. They need wide latitude (also referred to as the operating window) and a robust process to manage production efficiently, as a narrow latitude means small changes can push a print run out of tolerance. By resisting unwanted ink spread, printers have the power to keep the press running with a low risk of getting to unacceptable print.”
Schlotthauer justified her remarks and cited an example. “If an unscheduled press stop to clean plates takes about 10 minutes, and a typical billable press rate is around $700/hour, you can easily start doing the math about the financial benefits in eliminating some of these stops. Add in the reduction of waste material and post print capacity implications, and the need to address unwanted ink spread proves to be a particularly significant one.
“With lower dot gain and significantly reduced ink build-up during a run, PureFlexo Printing brings a more predictable match to a press color profile and reduces the need to stop the press to clean plates,” Anderson emphasized. “This results in much greater production efficiencies while producing a high-quality result. The complete prepress and printing process becomes more efficient.”