Original article from flexography.org
As the technology for flexographic printing continues to evolve, both quality and efficiency are improving. In order to remain competitive, flexographic printers must stay informed about the latest developments.
Once a sort of “halfway point” between offset and gravure, flexo has come into its own in recent years, in many cases taking volume that might otherwise have gone to one of those print processes, or even digital printing. This is due to its improved quality and ability to profitably produce the shorter runs the market often demands.
Another big change is around environmental sustainability issues, of increasing importance to many brands. Historically, most of the sustainability concerns revolved around the plate making process:
Was the process using water, solvent or thermal imaging?
How much solvent and energy were required to make plates?
What types of toxic chemicals were used?
What were the costs associated with managing, storing and disposing of them?
Recent customer experience takes the discussion in another direction: With the right plates, many environmental issues are minimized—not in plate making, but in the printing process. At the same time, quality goals can easily be met and press uptime can be significantly improved. This is important for several reasons:
With a higher uptime standard, a flexo press will deliver more throughput. More jobs and more volume through the press equates to more revenue and profit
When the press is down because plates need to be changed or cleaned, not only is more time consumed, but also more waste is generated as the press once again comes up to color
Less print production time translates to less energy usage, improving the environmental footprint of the print job and helping keep costs in line
Water-Washable Plate Benefits
The challenge for plate manufacturers has always been to create a more environmentally friendly plate without losing the benefits and advantages of quality and efficiency. Water-washable plates were developed to meet that challenge and to help printers and converters approach their operations from a much more holistic perspective. In addition to delivering excellent quality, these plates ensure a lower CO2 footprint in print production with a much higher press OEE (Overall Equipment Efficiency). Average improvement in OEE with water-washable plates is 33 percent.
In flexographic printing, highlights can usually cause two potential problems. The first is the highlight breaking point, which prevents a vignette from printing smoothly to zero. Photopolymer flexo plates usually start printing highlights at 5 percent to 8 percent due to dot gain, in the best cases. This means that gradations in vignettes suddenly break at that level, producing a visual contrast with the substrate; a visible breaking point or line well recognized as a print fault in the industry.
This breaking point is virtually eliminated using water-wash technology due to its smaller dot size, low dot gain and high dot stability, especially when used in combination with the latest generation of screening technologies. Extensive plate trials and live production jobs have proven the plate’s ability to print down to 2 percent to 3 percent using classical round dot screening. With the latest screening technologies, the plate is able to reproduce a vignette fade to zero.
Noteworthy benefits listing out as improved press uptime and OEE, reduced waste, profitable production of short runs and faster time to market are making flexography more competitive against offset, gravure and digital print. Industry awards continue to bring the process validity and forge flexo’s recognition as packaging’s preferred print method.
Gateway Packaging: OEE Up 53%
With less downtime, faster run-up to color, minimum waste, lower energy costs and consistent quality throughout the run, water-wash technology is improving flexography’s sustainability footprint. The experience at ProAmpac’s Gateway Packaging illustrates these points.
Many now say plate making is the central focus of the bigger picture view of flexography’s environmental sustainability initiatives. Here is one story to illustrate the point.
Based in White House, TN, Gateway Packaging (who ProAmpac acquired in May 2018) is a high-end printer/packaging converter and the largest pet food packaging provider in North America. The company is continually seeking ways to improve products and solve problems for its customers. To meet that goal, Gateway recently completely revamped its flexo plate making process.
“With the variety of flexographic plates and plate making solutions available in the market, we wanted to do a thorough evaluation to ensure our investment decision was the best possible choice,” said Tharrin Akers, prepress manager. “With that in mind, we benchmarked solutions from the leading players, ultimately bringing our selection to two, including Asahi Photoproducts. As a final test, we ran several production jobs using plates to compare efficiency with our current process, and we were very pleased with the results.”