Why is a new flexo plate-making system from Kodak causing such a stir amongst label printers? If you’re a flexo label printer and can answer yes to any of the following questions, then it’s probably worth reading on to find out.
Are there times that you struggle to compete with offset and digital for print quality and consistency? Would it be of value if you could print better quality and with better plate life on uncoated stocks? Would you like to be able to expand the range of security and microtext features you can offer clients? If you had a chance to do any or ALL of the above AND increase your robustness and efficiencies on press at the same time, wouldn’t that be tempting?
The KODAK FLEXCEL NX Digital Flexographic System opens new doors for Flexo printing of labels, while meeting modern production demands.
The FLEXCEL NX System received the FFTA/Flexo Market News Technical Innovation Award in Orlando on May 3, 2009, adding to a collection of similar awards from the FPPA (Flexographic Pre-Press Platemakers Association) and PIA/GATF (Printing Industries of America/Graphic Arts Technical Foundation) in 2008. Much has been written and said about the FLEXCEL NX System—some correct, some incorrect—and yet its performance and application on press is gaining it increased usage daily as companies look to improve productivity and profitability going forward in this tough economy.
Narrow-web printers and converters using FLEXCEL NX are also winning a good number of print awards—from the FTA, PIA of Southern California, and others—particularly in the narrow-web and label markets, where the abilities to practically print commercially at AM screens up to 300 lpi or FM screening at 20 micron are opening many doors as Flexo competes with offset and digital printing and differentiating them from other flexo printers.
So why invent a new digital plate-making system?
Digital laser ablative mask system (LAMS) flexographic plates that make use of a black mask layer on the surface of the photopolymer are not new; they were introduced in 1995 and have been in regular use for more than a decade. The consumer goods companies who buy our printed products regularly complain about the lack of predictability, consistency, and repeatability of Flexo. While it can produce print quality to compete with offset, gravure, and digital printing, they never knew day to day what they would get. This issue grew to such an extent that in Europe there was a trend back from Flexo to gravure for the consistency and predictability they desired. This confirmed that digital LAMS plates were not helping Flexo grow, and, in many cases, were holding it back.
Kodak re-evaluated the situation, and it was clear that critical to the plate inconsistency was imaging of the black mask and then the plate exposure through the black mask with oxygen present, causing dot shrinkage and rounded bullet-shaped dots. To address this, Kodak created an alternative way of making the digital Flexo plate, using proven KODAK SQUAREspot Imaging Technology, from offset, a FLEXCEL NX Thermal Imaging Layer, lamination, and no oxygen inhibition. The result is the KODAK FLEXCEL NX Digital Flexographic System.
Rounded LAMS Dots Image
So, the FLEXCEL NX System was created to address many of these issues and to produce unprecedented flexo plate capabilities using a flat top dot structure and 1:1 image transfer from the digital file to the plate, pixel for pixel.
What are the benefits to the users?
One of the reasons that narrow-web and label printers have taken to FLEXCEL NX so well is that many already had higher line, lower volume anilox rolls and higher specification inks, etc., to print process work and the like at up to 150 lpi today. So, for them the transition was easier, the components were in place, and the one piece missing was the higher capability plate.
Quality to compete with offset and digital print with photo-realistic images
Process printing is essential to label printers competing with offset and digital, where the less that needs to be done to files already prepared for one of those technologies, the easier it is for the buyer or printer to move the jobs to Flexo. To achieve good process printing, the predictability of the plates and the color achieved is critical to productivity and performance, throughout the production run and when reusing the plate on reruns.
When you trust the accuracy of the reproduction and the stability of the printing process, it allows greater use of process printing. With other flexo plates, it is difficult to predict that every dot is going to print throughout the run, so jobs using process color separations could look different from the beginning of the run to the end.
With traditional digital flexo plates it’s safer to use spot colors to get consistent color, but using spot colors adds cost in terms of both materials and time. On press, converters using process color separations typically use fewer plates per job. Also, they reduce the time it takes to set up and switch jobs, increasing both their productivity and their flexibility.
Squarespot Image
Because the imager uses KODAK SQUAREspot Imaging Technology—the same thermal imaging technology used in high-resolution offset plate making—it produces extremely accurate dots on the Thermal Imaging Layer. The dots imaged on the layer are a perfect match to the pixels in the ripped file. The intimate contact between the imaged emulsion on the imaging layer and the photopolymer during the lamination step ensures 1:1 transfer of these dots from the layer to the plate.
1:1:1 Image
Having the 1:1 image transfer from the digital file to the plate with FLEXCEL NX allows for a full tonal range using all 256 gray levels, enabling process printing to achieve predictable print results with greater contrast and image definition for images that are typically challenging for flexo. With the flat-top dot structure, higher ink transfer is achieved without loss of image quality through impression changes, resulting in stable expanded color gamut capabilities when using process printing.
Achieving higher print capabilities on a wide varieties of substrates, including uncoated
The label industry is increasingly using a wide variety of printing stocks, whether coated, uncoated, or specialty for functional, artistic, or financial reasons. The ability to print higher capability graphics, even on the uncoated substrates that are popular today for wine labels, is highly appealing to the industry competing daily against offset and digital printing. As an example, Labeltronix from California, who in April and May won awards at both the PIA of Southern California and the FTA, prints routinely on coated stock up to 300 lpi (118 lcm) and 20 micron FM screening, as well as uncoated stock up to 279 lpi (109 lcm).
Flat Top Dot 3D Image
Because flexo depends on pressure to transfer the ink to the substrate, variations in the substrate and impression pressure applied by the operator can cause inconsistencies. Often with traditional digital flexo plates, operators can have a significant effect on the print result though impression changes. Rounded dots will print small dots with light pressure, and they will print larger dots as pressure increases. The differences in print surface height between dots and solid areas cause speed differences than can increase dot slur, banding, and or gear marking. The flat-top dots on Kodak’s plates print consistently despite impression variation, flat-top dots print the correct size dot with light pressure, and the change in dot size is minimal even as pressure increases. Wide impression latitude and low sensitivity to impression settings, even on uncoated stocks, enable faster press setup and greater print stability, not only for maintaining print quality during a single run, but for achieving the same print quality on subsequent runs.
Critical to the success on more challenging substrates and surfaces like uncoated or envelope stock is the dot structure and its effect on plate life. With its flat-top dot structure and even height of solids and tone, the FLEXCEL NX Plate distributes the impression pressures, reducing stresses and wear, increasing plate life and giving a greater advantage on these lower-cost and more-challenging substrates. This extended plate life is allowing printers to run longer, or more commonly reuse plates more and more for reruns, meaning even greater consistency run to run, achieving the customer’s expectations of predictability of final print, reducing costs, and improving sustainability.
Printed security features and micro text down to 0.5pt
The product label is a key component in the front line as many companies fight against the counterfeit producers, with many overt and covert security methods available. One of the potentially simplest methods for security is to add data or an identifier to the print that can only be seen under magnification, such as micro text. The addition of these features using FLEXCEL NX is relatively simple as a line or box around an item, or incorporated into more sophisticated designs. It adds significant value to the label for the buyer, and to date has been commercially applied to labels between 0.8 and 0.5 pt text. Other options that benefit from the 1:1 image transfer of FLEXCEL NX capabilities are 2D bar codes and other overt security features that can also be optionally combined with covert security features like the KODAK TRACELESS System.
A key part of the FLEXCEL NX process that makes this possible is the lamination step. In addition to providing 1:1 transfer of the dots to the plate, lamination removes all oxygen from between the layer and the plate. When oxygen is present during plate exposure, it causes what is known as “oxygen inhibition.” Oxygen slows the dot formation on the plate, resulting in dots that are not full height and that are bullet shaped—they have narrow bases and rounded tops. With Kodak’s flexo system, lamination eliminates the oxygen inhibition problem, so the dots on the plate are the correct size and full height with stable bases and flat tops. Because of the oxygen present during exposure of traditional digital plates, on the other hand, dots on these plates shrink during exposure, have rounded tops and narrow bases, and small dots do not reach full height, making small features like micro text very hit and miss in production.
On Kodak’s plates, even the smallest dots and lines in the original file are created on the plate as full height, printable dots.
Productivity in production, essential for profitability in short- and long-run work
Flexo printers using traditional digital Flexo plates typically spend significant time setting up the press to achieve sign off, even with modern fast change presses, the time and materials used to bring the print to color varies tremendously, with often some parts of the print coming in quickly, but a long time then required to get the rest into color, with potentially visible differences with multi-repeat labels in the final results.
Making the FLEXCEL NX Plates very predictable, having the solids and tone at the same height, means that all types of printers report that the plates come in together, very quickly and very consistently. This has allowed label printers to generally reduce setup time, waste less material, and in some cases turn their Flexo press into an “on-demand” operation, competing directly with digital print. The predictability of the plates and their performance is critical to allowing customers to update their business models and achieve greater profitability.
Having predictability in prepress can also enable you to successfully automate your process for added efficiency and productivity, and it helps to eliminate unnecessary plate remakes. On press, predictability can help printers significantly reduce the time and material spent on make ready. In addition, repeat runs are easier to set up when you know that the prints will look the same as those from previous runs
Predictability is only one piece. To truly get cost and productivity benefits, a printer needs to be able to get the most out of each and every plate. Making new plates and stopping and restarting the press to clean plates or change plates are the real time and money burners.
Narrow-web printers and converters increasingly are printing shorter and shorter production runs, with more jobs repeated daily, weekly, or monthly instead of being produced in one long run and stored, so setup time and repeatable reusability of the plates is critical to the productivity and profitability of the operation. The flat tops and stable bases of the printing dots created with Kodak’s system are the secret to the durability of Kodak’s plates. Durability enables longer run lengths, increased resistance to damage from cleaning, and consistent color throughout the print run. They also allow the reuse of the plates more often, with quick changeovers, especially when using consistent ink/anilox/tape combinations.
Helping to drive the flexo industry forward as a whole?
It has been said by many that the FLEXCEL NX System is having a very positive change on the Flexo industry as a whole already. It is clear that the efforts to develop prepress solutions to try to match it is causing suppliers to invest more in R&D for Flexo, and that can only be good for the industry after many years of few significant changes.
In response to FLEXCEL NX, options using combinations of higher LPI and screening technologies are coming forward, and although showing improvements in areas like text and edge smoothness, the underlying individual technologies are neither new nor revolutionary. Increasing the imaging resolution from 2540 to 4000 dpi increases the data to RIP and image by about 2.7 times each, and you just can’t spin the drum fast enough to make that lost productivity up without potential issues in imaging and equipment life. The use of advanced screening technologies for dot enhancement is nothing new and has been winning awards since 2003, when KODAK HYPERFLEX Software won a GATF InterTech award. However, none of these address the fundamental issues of traditional digital plates—the rounded tops and the effects of oxygen inhibition. Kodak is the only supplier of digital plates to fundamentally address the profile of the printing surface itself, and the FLEXCEL NX results speak for themselves.
What’s next?
Brand owners, printers, converters, and trade shops using Kodak’s new system are impressed with the gains in print productivity and efficiency that they’re seeing today, along with the obvious image capability enhancements. And the benefits they’re seeing today are the base system. Kodak recently added the upgrade capability to image offset plates on the system’s imager (hybrid option), allowing users to image multiple media types, the Thermal Imaging Layer for FLEXCEL NX, DITR films for making analog flexo plates, and offset plates, reducing their equipment costs by imaging everything on one device.
Also, keep your eyes open for more developments coming soon with this system. Kodak is not standing still and will have more revolutionary technology ready for commercial application soon. Work continues on software and imaging development, thermal ablative films for analog plate imaging, as well as washout solutions, and novel cold recycling technology for washout solution recovery that eliminate the need for distillation. Kodak has long been a leading innovator in the offset printing industry, and now that it has set its sights on the packaging segment, you can expect to see some exciting new solutions.
For more information visit www.kodak.com/go/flexo |
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