INDUSTRY EQUIPMENT


High Performance Aqueous Plate Technology: It has been a long time coming

26/03/2020

CATEGORY: Machinery and applications BRAND: Kodak


A superior quality process free printing plate, or at the minimum an aqueous process plate has been a goal for printers since the days of hand engraved plates as a way to streamline the platemaking process.


Bill Schweinfurth

 

High Performance aqueous plate processing finds its roots in a 1948 Kodak patent which is the foundation of photopolymer imaging. Offset plates have progressed, although until recently Flexo platemaking had trouble reaching that goal.

 

Aqueous plate processing finds its earliest roots in a 1948 Kodak patent which is the foundation of photopolymer imaging. A process free printing plate, or at the minimum an aqueous process plate has been a goal for printers even before that invention since the days of hand engraved plates. Development took some time, but market availability and adoption of aqueous processed plates began in earnest after drupa 2004, and now 15 years later with the increasing pressures of environmental sustainability it has finally become the primary method of offset plate processing. Although the unique challenges of flexo platemaking have added complexity to achieving that goal.

 
Challenges of Flexo

The earliest of flexo relief plates were composed of rubber and the resultant print was not of the highest quality. The introduction of photopolymer flexo plates helped increase the quality but not that much in comparison to offset or gravure, two of the primary packaging print technologies. The subsequent introduction of CTP imaged photopolymer flexo plates in the mid 1990’s provided much higher resolution and tighter controls to the platemaking process, but still didn’t achieve the quality of offset or gravure.

 

One of the challenges of flexographic printing is that the flexo plates image directly on the substrate creating plate wear and therefore impeding run longevity, as well as print quality. The flexo plate, unlike offset, is without an aluminum backing thereby making it an inherently soft surface, in comparison to offset plates, which makes it harder to achieve a small minimum printing dot or maintain a durable dot structure in general over the course of a press run. In order to mitigate these issues, flexo plate manufacturers have developed different plate materials, exposure and processing solutions.

 

 

The most widely used method of flexo digital platemaking today uses a plate that has a LAMS (Laser Ablative Mask System), which is a black carbon mask layer manufactured directly on the plate, that is then exposed with a digital laser imaging device that ablates the image area from the carbon mask. Flexo plate and laser imaging technology has continued to improve over time along with image quality, however the LAMS process still doesn’t offer the level of control or detailed reproduction we would typically find in offset or gravure platemaking. With their significant imaging background, at drupa 2008 Kodak introduced FLEXCEL NX, the first step in an alternative solution developed using their long history of imaging and offset platemaking. This process uses a Thermal Imaging Layer (TIL) mask, which in essence is exposed film that is then laminated with a unique laminating process providing a 1:1 reproduction to the Kodak polymer flexo plate material. The plate is then developed in a solvent based solution to wash away the non-imaged areas.

 

The TIL can produce much cleaner image mask and the plate can be produced with smaller flat top halftone dots with broad shoulders to help stand up to the direct imaging on the media. The plate can also carry ink more consistently and require 3-4 times less energy to image the TIL compared to LAMS.

 

High Performance Aqueous Flexo Platemaking and Processing

Efficiently and completely removing residual material from the exposed and processed plate has proven to be a challenge over the years for many plate manufacturers. Additionally, since the flexo plate dot structure and process requires a tall dot in order to create a shoulder to maintain the dot under the pressure of compacting it against the media, there is a good deal of residual non-print plate media that needs to be removed or washed off. If not washed out properly developed plate debris ultimately redeposits on the plate causing print defects.

 

This issue can be further compounded if the surface of the plate is textured – where a textured surface can act as an additional trap for debris. (Note: The most sophisticated plate systems use imaged micro texturization patterns to control both ink transfer and ink flow and can be highly successful in achieving high density, smooth ink laydowns while minimizing actual ink usage.)

 

Solvents initially proved to be more efficient than water for plate processing and washing off the residue but brought with it solution handling and waste disposal issues, until now.

 

In an effort to achieve a high performance aqueous flexo platemaking solution, at Labelexpo 2018 Kodak – now Miraclon - introduced the FLEXCEL NX Ultra system, their latest evolution of the FLEXCEL NX product line. FLEXCEL NX Ultra uses the same basic TIL technology, but unlike the current FLEXCEL NX which uses a solvent based developer, FLEXCEL NX Ultra uses a new aqueous based development process that is solvent and VOC free. The new Kodak Ultra Clean technology uses a specially designed plate processor and a specially designed processing solution with a dispersing agent.

 

Miraclon’s KODAK FLEXCEL NX Ultra plate processor develops the latent image into a relief image by removing the unexposed photopolymer from the photosensitive flexographic printing plate using this unique aqueous processing solution while the plate is being mechanically cleaned. The unique patented process uses natural-based agents to prevent the build-up of unexposed polymer on the plate and the plate processor itself – ensuring both the quality of the plate and a minimal amount of maintenance and cleaning for the operator. The system is also fast, only seven minutes to process a plate – and with the rapid drying times possible with an aqueous-processed plate a printer can have a press-ready plate, from beginning to end, in less than an hour. And as for waste products, the spent solution is drained out of the processor as a combination of reclaimed water and inert by-product for treatment and municipal disposal. The combination creates a level of quality, efficiency and sustainability not seen before in flexo platemaking.

 

Ultimately the Customers are Excited

The benefits are apparent to the European and US early adopters. Krzysztof Malengowksi, Fleksograf Owner, comments: “Adding FLEXCEL NX Ultra to our offering is not just great news for our customers, but also allows us to expand into new markets. Sustainability is at the forefront of many of our customers and brands’ requirements, and we are setting a new standard with Miraclon’s aqueous, solvent-free flexo plate solution. With FLEXCEL NX Ultra, sustainability can now start with the plate while still delivering the same high quality, consistent results that Miraclon’s other FLEXCEL NX Solutions are well-known for.

 

In the twenty-first century packaging industry, eco-friendly printing begins with the flexo plate,” says Stefan Schneider, Sales Coordinator at U. Günther. “The KODAK FLEXCEL NX Ultra Plates also have a whole series of handling, quality and productivity benefits for packaging printers. Tests and initial production runs have confirmed that the plates deliver excellent print quality with high edge definition. There is much less ink build-up during print production, so printers benefit from longer cleaning intervals and less downtime. Print production speeds can also be substantially increased.”

 

“We have a green initiative in our facility” explains Rob Anderson, Director, Production and Planning, IGT, a major lottery ticket printer based in Florida. “So, knowing that NX Ultra was to be a water wash product and we wouldn’t have to deal with solvent-based processing it was very appealing to us. The operators of our flexo presses really appreciate the Miraclon plates. They see the difference in the dots and how they print and how vignettes, our fine screens, how everything looks so much cleaner and essentially it has made their job much easier. The NX Ultra product itself has been all that has been promised. We can get plates much faster and we’ve accomplished our green initiative. We truly look at Miraclon as a partner.”

 

Problem Solved

High performance flexo platemaking and processing has come a long way since the invention of photopolymer imaging in 1948. With the addition of the KODAK FLEXCEL NX Ultra aqueous solution from Miraclon, achieving the goal of an environmentally safe and sustainable process provides flexo print providers with a solution that will continue to support high quality print, increased productivity and lower costs for years to come.

 

By: Bill Schweinfurth, Worldwide Product Marketing Manager, Miraclon

 

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