Finding a Solution for Uniform Ink Issues on Corrugated Board

For those of us involved in flexographic printing, we cannot help but inspect packaging no matter what the substrate may be. It is a habit we just cannot seem to break and I attribute it to a deep appreciation of printing techniques.

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For those who want to learn more about DuPont Cyrel DLC, a FLEXO Tech Talk—titled “More Ink, Less Crush”—can be accessed on FTA’s MemberConnect.

I am pretty sure many of you have gotten some strange looks from folks in the grocery store as you are analyzing the printing on various packages and may even be critiquing it in your head. When analyzing packages, one of the biggest and most noticeable print issues is the printing of a good solid, regardless of the printing application.

A Challenge…

The ability to cover an entire printed surface—especially an uneven surface such as a corrugated board—with uniform ink coverage has always been a challenge. It has become even more challenging now with increased usage of thinner corrugated board liner material and the increase of recycled paper used to manufacture corrugated board. 

Part of the challenge results from the balance a printer must strike in putting enough pressure between the printing plate and the substrate to create a good solid. A printer must deliver this without crushing the flutes, which could weaken the board beyond its specification. Using traditional printing plates with a Shore A durometer of 33-34 for a 0.250-in. thick plate (let’s call this durometer a “standard durometer” plate) was perfectly fine when liners were thicker and stronger. However, with a trend moving toward thinner liners to directly reduce raw material costs, using a softer durometer plate is now the best option to optimize printing excellent solids on corrugated board, specifically B and C flute.

…And a Solution

DuPont Advanced Printing introduced a new, low-durometer corrugated sheet photopolymer printing plate named DuPont Cyrel DLC. Cyrel DLC is a softer plate that conforms to the uneven surface of corrugated boards and provides a smoother ink laydown. A softer plate provides better impression latitude for press operators, which is a key benefit since boards and presses have wide-ranging variation.

Additionally, this plate has shown to outperform current “standard durometer” printing plates in DuPont internal and external print trial evaluations. DuPont has benchmarked this new plate against its own 33 Shore A plate and several other competitive plates, both with standard durometers and lower durometers. The early success of this new digital plate has brought a lot of enthusiasm to those customer probe accounts.

“The ability to cover an entire printed surface—especially an uneven surface such as a corrugated board—with uniform ink coverage has always been a challenge. It has become even more challenging now with increased usage of thinner corrugated board liner material and the increase of recycled paper used to manufacture corrugated board.”

DuPont Advanced Printing believes this new plate is a win-win for both corrugated tradeshops and printer/converters. The DLC offering provides corrugated tradeshops a high-quality, DuPont-manufactured photopolymer printing plate to offer their customers to complement its DPC plate targeted for use with high-end graphics. We have also found that DLC provides excellent over-impression latitude, which is very important to corrugated printer/converters. DuPont has data provided by the Clemson University Packaging Science Lab in Columbia, SC to demonstrate and confirm this exceptional benefit.

The impression latitude and excellent solid ink coverage will vastly improve designs with large solids and text, which make up a large portion of corrugated printing. DLC will be offered in a variety of thicknesses and sizes to meet the global demand.

About the Author: With more than 30 years at DuPont, Bob Hannum has been active in the flexo industry with the DuPont Cyrel business for the past 27 years. He currently has dual roles as the North America corrugated segment manager and corporate account manager for DuPont Advanced Printing. He is a member of FTA, FPPA, TAPPI and AICC. Bob and his wife reside in Charlotte, NC.

DuPont Advanced Printing, a DowDuPont Specialty Products Division business, brings together leading technologies and products for the printing and package printing industries. DuPont Cyrel is one of the world’s leading flexographic plate making systems in digital and conventional formats, including the new Cyrel EASY photopolymer plates and Cyrel FAST plates and processing equipment.