Executive Forum: Anilox Roll Engraving

Benefits from today’s anilox rolls include dot gain reduction, improved color quality, and longer roll life—just to name a few.

April 2006 by Tom Polischuk

multipage

Anilox rolls are often considered “the heart of the flexographic printing process,” as Dr. Lloyd Dreger of Laserlife points out below. As such, anilox rolls have played an integral part in the quality improvements that flexography has made in recent years in the packaging arena. To get a first-hand perspective on the impact these rolls will continue to have in package printing, packagePRINTING posed a series of questions to executives at the front lines of the industry.

pP: Flexographic printing has made great strides in improving its quality to better compete against offset and gravure. How have improvements in anilox roll technology contributed to this?

Aaron Lessing, director of sales and marketing, N.A., Apex North America—As quality demands approach and surpass those of gravure and offset, the anilox roll requirements have been directly affected. Higher linescreens of plates and higher speeds of presses both necessitate the following: LPI is increasing to produce finer plate screens; volumes have to be right on, as presses with significantly better tolerances leave less room for error; and consistent cell release has to be there, meaning that as the roll ages, surface tension or release characteristics must remain the same so that ink formulations don’t have to change due to a roll not releasing the same as it gets older.

Art Ehrenberg, vice president global manufacturing operations, Harper Corporation of America—Advances in release properties of anilox surfaces and new cell configurations have made it possible to continue increasing cell count and volume which aids tremendously in the ability to increase print fidelity.

David Skellie, president, Interflex Laser Engravers—Newer generation laser technology has allowed finer print quality through high-definition anilox line counts. These higher line counts also have increased cell volumes and enable printers to utilize finer plate screens that are necessary to compete with gravure/offset printing. High-definition anilox line counts allow the plate to print finer detail (1 percent dot on digital plates), yet bring up required densities.

Dr. Lloyd Dreger, technical director, Laserlife—The anilox roll, the heart of the flexographic printing process, is one of the major contributors to improving printing quality. The trend to more engraved cells per given area on the anilox roll surface has reduced the amount of air trapped in the ink. A cone of ink forms from each cell at the interface of the anilox roll and the plate cylinder. More ink cones for a given surface area means less air between cones. Less air in the ink results in a reduction of dot gain giving the printer the ability to print sharper edges on solids and lower percentage of process dots when doing process printing.

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