Is there a digital press in your folding carton future? It's here today with digital print solutions to supplement offset, flexography, and gravure. This paper describes the fundamental differences and best application for the various technologies including electrophotographic, ink jet, nanography, digital creasing, and laser cutting.

1. 1
Digital Package Printing . . . . . . . . . by Dan Malenke
Is there a digital press in your folding carton future? The practice of digital printing has
grown in recent years and is now finally showing real potential for folding carton
applications. A new dawn is upon us. New digital presses, inks, coating, and finishing
systems are on the horizon to capture the hearts and pocketbooks of converters, brand
owners, retailers, and consumers. Digital printing offers another dimension to product
promotion and sales, redefining traditional supply chains, and introducing a model for
fast-turnaround, customized, variable print packaging that is literally “on demand”. To
understand this new paradigm, it’s appropriate to describe what digital package printing
is and how it has evolved.
Offset lithography, flexography, and gravure are the process standards, having dominated
the folding carton industry for decades. Offset is a workhorse for the printing of high
quality graphics on a variety of substrates. Flexography, also known as flexo, is more
common with commodity packaging although its capability has expanded through
advancements in press, plate, ink, and pre-press systems for the printing of bright, vivid,
multi-color images. Gravure maintains a significant market share for the high volume
printing of brewery, detergent, and tobacco packaging, among other items.
Offset, flexo, and gravure rely on physical and/or chemical means to transfer images1
.
Digital printing, however, is an electronic form of imaging where particles of pigment are
sprayed, ejected, or drawn to the substrate as directed by pulses of energy. Digital
printing appeared in the early ‘90’s with the first electrostatic press from Indigo
providing inexpensive short-run color printing first on paper, then to a variety of other
materials. Narrow web toner-based and digital ink jet presses with inline die cutting are
now common for small format label printing from manufacturers including HP Indigo,
Xeikon, Domino, Primera, Epson, Jetrion, OKI, Durst, and Xante.
Conventional printing expresses tonal print quality in increments of screen ruling. The
term “120 line screen” indicates that there are 120 halftone dots per linear inch. This
level of quality is characteristic of conventional flexography with analog image
processing for folding cartons. Offset lithography commonly uses 150 line screens and
higher screen rulings can be used with the smoothest substrates for offset and rotogravure.
High definition flexo is also capable of some higher screen rulings.
In digital image processing for conventional printing, halftone dots are constructed of
definable image specks known as pixels and the resolution is expressed in dots per inch
(dpi) or pixels per inch (ppi). A higher level of dpi produces sharper, rounder dots with
higher definition (Illustration 1), even with conventional screen rulings.
Illustration 1: Line Screen vs. DPI Resolution
Digital printing, on the other hand, always builds tonal images with tiny droplets of ink
corresponding to the individual pixels. Digital printing can be found in the range of 600

2. 2
to 2400 dpi. Halftone dots are done away with, as are prescribed screen angles, which
can sometimes be challenging with conventional four-color process printing.
Digital printing has contributed to folding carton solutions, but hasn’t previously been
widely recognized as a primary printing process by restrictions of format, size, volume,
and speed. Digital presses were typically 13 inches or smaller in width. These are
perfect for labels and short run publishing, but most folding carton applications start
around 26 inches wide2
.
Paperboard for digital printing was largely restricted to lower caliper (10-12 pt.) solid
bleached sulfate which has a slightly lower moisture content than other substrates and
accommodates digital imaging at reasonable production speeds. The newest digital
presses solve these issues with formats as wide as 30 inches, production speeds up to
3,500 sheets per hour, and web speeds up to 100 feet per minute. Some systems may also
include inline coating, cutting, and finishing capabilities. Various grades of paperboard
can be printed at calipers up to 24 pt. and the print quality is quite impressive.
In the current landscape, there are three approaches to digital printing for folding cartons:
Electrophotography, Ink Jet, and a form of indirect Ink Jet - Nanography.
Electrophotography (EPG)
Otherwise known as Xerography or laser printing, this process uses pigmented toners,
electrostatically drawn to the substrate. HP Indigo has recently announced several 29.5”
format presses specifically for flexible film, paperboard sheets, and web-fed paperboard
up to .024”. As many as seven dry toner print stations will accommodate process color,
spot colors, opaque white, and colors for extended gamut printing.
Another dry toner press that can accommodate large format paperboard is from Jadason
Technologies and smaller format presses are manufactured by Xerox, Kodak, Konica
Minolta, Ricoh, and MGI.
Liquid toners may have some advantages over dry toners since heat isn’t required to fuse
the image. Production speeds are quite fast and the print quality rivals that of offset
lithography. Leaders in this area include Xeikon, Canon-Oce, and Miyakoshi.
Ink Jet
Ink jet uses droplets of propelled liquid toner in one of two technologies known as
continuous inkjet (CIJ) and drop on demand (DOD). The most mature technology, CIJ
directs a microscopic stream of ink through piezoelectric printing heads, electrostatically
deflected to the substrate. This process has a diverse market from packaging and
document printing to industrial applications for textiles, ceramics, flooring, building
materials, printed electronics, and product labeling. Since the stream of ink is continuous,
this process doesn’t have issues with plugging or drying in the nozzles.

3. 3
DOD ink jet propels only those droplets of ink that are intended to print. Most consumer
desktop ink jet printers are, in fact, drop on demand. Wide format presses have employed
this kind of ink jet for signage since the 1990’s. High speed ink jet also allows for
product coding and personalized printed communications. With drop-on-demand ink jet
printing, a process known as “material deposition” makes it possible to build up layers of
ink or coating through multiple passes. This technique can simulate an embossed surface
and create soft touch textures in an overall pattern or in prescribed areas.
Ink jet is just now entering the folding carton industry and has certain advantages over
electrophotography. Large format printing is right at home and, unlike existing web
offset and flexography, there is an infinitely variable repeat.
Breaking technologies are coming in the form of high resolution, high speed print heads,
and the use of incredibly efficient nano-inks. Presses are now reaching speeds of 1000
feet per minute and print resolutions have reached 1200 dpi. The leaders in this
technology include Kyocera, Delphax, Xante, Colordyne, Memjet, Oce, Toshiba, Fuji,
and Epson.
Nanography
A new digital print technology known as Nanography, was introduced in 2012 by Benny
Landa, digital printing innovator and original founder of Indigo. This new process
signals a breakthrough in printing inks as well as printing machinery. Nanographic inks
are microscopic water bourn droplets containing incredibly efficient pigment particles
only tenths of a nanometer in size. Nano pigments absorb more and scatter less light than
conventional pigment particles3
.
The Landa Press uses these inks which are ejected from high speed print heads onto a
heated, continuous belt. The water evaporates as the droplets are deposited onto the belt,
forming an ultra-thin polymeric film. This film is directly transferred to the substrate. It
bonds instantly, forming a tough, rub resistant image. Nanography provides high quality
printing on virtually any substrate at relatively low cost. It prints with the thinnest of all
ink films - less than half that of offset lithography – so it takes less energy to cure.
Illustration 2: Relative Ink Film Thicknesses
The Landa press provides 28” format printing in up to 12,000 sheets per hour for films,
paper, and paperboard. The user interface is a massive touch screen spanning the entire
length of the press and remote operation can also be accomplished through an internet-
linked smart phone or tablet.
Nanographic printing will impact traditional print processes as well. Various OEM’s
including Heidelberg, Komori, KBA, and MAN Roland, have signed partnership
agreements with Landa to integrate the nanographic process into their existing offset
presses.

4. 4
Hybrid Presses, Cutting, Creasing, and Finishing
Are printing presses imaging devices or assembly lines? Arguably, the next generation of
package printing presses will follow the lead of platform presses from manufacturers
such as Gallus and OMET, with independent printing units that are shaftless, gearless,
and servo controlled. Print stations will be moved into any sequence combining the best
of flexo, gravure, and nanographic printing for one or two sided imaging. Embossing,
metallization, barrier coatings, aqueous overprints, UV film casting, and other UV
coating will all be done inline.
Inline rotary and reciprocating die cutting is common with folding cartons. Laser die
cutting eliminates the need for conventional tooling and can also cut cartons inline, but
until now, a gap existed with digital creasing. An interesting new system known as the
Highcon Euclid generates digital adhesive creasing rules that, combined with laser
cutting, makes it possible to crease and cut folding cartons without traditional die tooling
and the associated machinery4
.
Integrated production software orchestrates the interaction between pre-press, color
management, printing, and post-press operations; various inspection systems monitor
product quality. The combination of all these technologies brings excitement to the
folding carton industry!
Digital package printing allows for personalized and customized packaging. It can be
used in brand protection, providing overt and covert security features and improved
product authentication throughout the supply chain.
The market for digital printing is growing rapidly. According to Smithers Pira, digital
printing for packaging will be worth nearly $12.2 billion with an annual growth rate of
20.5% from 2011-165
. Just as smart phones have revolutionized personal
communications, digital printing is finding inroads into more and more packaging
solutions. Is there a digital press in your folding carton future? Probably so!
REFERENCES
1
Malenke, Daniel G., “A Comparison of Folding Carton Printing Processes”, Zumbiel Packaging White Paper, October,
2010 http://www.zumbiel.com/sites/default/files/Printing%20Processes-WP.pdf
2
Fenton, Howie, “Is the Digital Label Market Growing and Why?”, WhatTheyThink, December 17, 2010,
http://whattheythink.com/articles/53720-is-the-digital-label-market-growing-and-why/
3
Milmo, Sean, “NanoInk May Lead to Gains in Digital”, Ink World, August 2012
http://www.inkworldmagazine.com/articles/2012/08/landas-nanographic-presses-nanoink-may-lead-to-gai
4
Ferrari, Michael, “Digital Cutting and Creasing”, Folding Carton Industry, March/April 2012,
http://www.mike-ferrari.com/fcmag-cutcrease-2012-03.pdf
5
SmithersPira, “The Future of Digital Printing for Packaging”, December 2011, http://www.smitherspira.com/future-
of-digital-printing-for-packaging-to-2016.aspx