BY DAVID ZWANG
When we look at the historic packaging print technologies—flexography, offset, gravure and electrophotographic—we now see the added competition of production inkjet which is finally starting to achieve the quality, size, and increased performance necessary for many packaging applications. Although, unlike the transformational technologies that are affecting commercial print, packaging puts even more stringent demands on quality, productivity and cost. Offset printing has reduced many of the labor functions and time required to make ready and control the process in defense of market share. Digital print technologies like electrophotographic and production inkjet add on-demand and variable data features, and while the quality is there, cost and performance are still lagging and probably will be for quite a while.
In the meantime, flexography, the overwhelming leader in packaging print production has been going through a technological rebirth. As I have discussed in the past, there have been many digital enhancements brought to the flexo process. The result can be extremely high-quality print, while still providing high productivity and low cost creating a significant defense against other print technologies. While the basic concepts of flexography have not changed, the introduction of digital enhancements are affecting everything from the transport to imaging, providing significantly enhanced automation, quality and control that help producers to improve operational efficiency and reduce environmental footprint.
In the area of transport, the use of visual and other sensing technologies combined with digital servo controls, enables less operator involvement and better control. In imaging, the use of precisely controlled plate imaging technology and sophisticated digitally surface textured plates like we have seen with the FLEXCEL NX Technology from Miraclon (Hall 15/F50) have been able to not only bring the printed image quality in line with offset, gravure, and digital technologies but also open up efficient print production practices that are not typical for flexo. Printing by numbers, extensive use of process color printing, co-printing of designs side by side on the web, characterize what is being referred to a modern flexo. Ultimately, it is the plate that is a key enabler for the quality, performance and sustainability benefits delivered by modern flexo. Through the continued development of the plate surface patterning, it has provided the flexo process with new levels of control of ink transfer. The scanning electron microscope (SEM) images in the illustration below clearly show the progression.
The most recent development in this area, released to the market as PureFlexo Printing, has addressed unwanted ink spread. Ink spread can increase the time needed for press setup, and historically has been mitigated through a reduction of press running speeds and unscheduled stoppages needed to clean the plates. Ultimately, better ink control leads to a reliable process with increased sustainability since you are reducing machine operating time and material waste.
Control in flexo ink manufacturing and ‘in press’ ink control have been seeing significant enhancements as well. Now converters can achieve results that are consistent and predictable enough to enable printing by numbers, even automatically with some press technologies. This has also been enhanced by work in the standards bodies, with efforts like ECG (extended color gamut) printing, which can achieve almost 90% of the Pantone color library with CMYKOGV, to reduce the need for ink color changes. Ultimately, success with ECG implementation comes down to a commitment to standardization and process control, and a plate technology that can guarantee the predictability and stability of process color builds.
The emergence of modern flexo and the emerging digital offerings now raise the question: what printing technology is ‘right’ for packaging? This is a difficult question that may not produce a binary answer. First of all, packaging print has many different applications: labels, folding cartons, flexible packaging, corrugated, etc. Each of them has its own unique requirements. While we usually think of digital technologies for on-demand and variable data, new digitalized flexo presses can print on-demand flexo at a much lower cost with higher productivity than any digital solution. Developments in hybrid flexo presses have introduced the ability to address variable data. Joint efforts by the members of the flexo supply chain have been able to create a new Modern Flexo.
The lack of skills in the industry, combined with the pressures on printers to increase yields and implement sustainability improvements necessitates less ‘craft,’ and more efficient, intervention-free printing that can cope with the full range of client demands, and this is where modern flexo comes into play—enabling printers to achieve their efficiency, sustainability, and quality goals.
So, very much like the benefits and decisions that we had to make with the introduction of digitalized offset presses as well as electrophotographic and inkjet, the most important question probably is: what are the application needs? And equally as important, what are the cost and productivity considerations? The packaging marketplace demands that quality, cost, and productivity are factors that have to be taken into account.
In the end, especially during technology transitional periods, the ultimate answer may not be binary at all, and you may need multiple technologies to address the variety of requirements.
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