What really is Kodak UltraStream inkjet technology? Find out here

UltraStream will set new standards, broadening the range of printable graphic arts applications and reaching new markets for high speed, high resolution inkjet printing. The technology will co-exist in the market along with Kodak Stream technology to offer different platform options, addressing the needs of each application.

UltraStream is aimed at printers and prospects demanding a superior image quality to integrate into their application-based production systems. This high resolution Writing System includes a modular printhead that can be implemented in varying widths ranging from 8-inch up to 97-inch to suit the specific application. UltraStream will also be available with Kodak’s Digital Front End (DFE), a dynamic and flexible solution that meets the demands of commercial printers as they implement production inkjet in their workflows.

UltraStream will enable high resolution printing of 600x1800 dpi at speeds of up to 150 metres per minute (500 ft per minute) on the widest variety of paper and plastic substrates, to address even the most demanding applications, including narrow-web labels, and packaging. It will also be available in a scanning head configuration to enable wide-format printing with multiple heads on a moving carriage. Kodak’s micro-milled nano-particulate inks deliver 30% wider range of colour gamut, and with the extensibility of the technology can also provide spot colours and an extended colour gamut to further broaden the scope of CMYK printing.

What really is Kodak UltraStream?
At Drupa 2016, Kodak will display the UltraStream technology in an 8-inch configuration on a narrow-web press for labeling and small format printing, to showcase the high resolution output as a result of smaller ink drop sizes, superior drop placement and substrate interaction.

If you are not visiting Drupa, or if you want to dig deep into the technology, Kodak has recently released a Whitepaper on Kodak UltraStream. PrintWeek India compiles the details.

Moving production inkjet into mainstream
The Kodak UltraStream technology is a complete inkjet writing system that will move production inkjet into the mainstream of commercial printing, packaging, and more. This technology demonstrates the evolution of inkjet with smaller drop size and precise placement accuracy for higher resolution, clean lines and additional detailed definition. The UltraStream technology will set new standards, broadening the range of printable graphic arts applications and reaching beyond to new markets for high-speed, high-resolution inkjet printing.

Drop generation
The UltraStream is Kodak’s fourth-generation continuous inkjet (CIJ) constant-flow method for high-speed digital printing, leveraged from the success of Kodak’s Stream technology. Stream technology has set the bar for digital printing, combining
high image quality and lowest running cost with a broad range of substrates. UltraStream technology elevates digital inkjet to another level, improving image quality to match o set and expanding substrate ranges, while continuing to produce the lowest cost per image at production speeds.

Continuous inkjet technology achieves these amazing results through Kodak’s fundamental development of proprietary technologies. At the heart of UltraStream technology are precise silicon nozzles that incorporate the latest industry advances in microelectromechanical systems (MEMS) and complementary metal-oxide semiconductor (CMOS) technology, as well as a simplified and elegant electrostatic drop selection scheme. The silicon nozzle plate consists of an array of 2560 nozzles with an approximate diameter of 9 microns positioned linearly at 600 dots per inch (dpi). Each nozzle has an annular heater positioned at the edge of the orifice (see Figures 1 and 2).

The silicon nozzle plate is attached to a print head manifold, which provides for a constant pressure and flow rate and produces a steady stream of ink. Using principles of physics, this steady stream of ink is broken into uniform droplets as each nozzle heater is activated. The frequency of heater activation is greater than 400 kHz and provides enough energy to weaken the jet filament by reducing viscosity and surface tension locally, at each orifice. Drops are then formed individually at velocities of 20 metres per second. The low amount of energy required to create ink droplets at the surface of the nozzle is less than a 5oC degree temperature rise from ambient, and is 50 times lower than thermal Drop on Demand (DoD) inkjet systems, which require temperatures to reach 100oC to create nucleation of the fluid.

UltraStream Technology’s low energy requirement provides a reliable and proven method of drop generation that is also robust: this technology has nozzle life of three trillion drops (see Figure 3).

The continuous inkjet drops are
the same size, providing uniform
character and line thickness, and enabling inherent colour stability over long runs, from one press to another, and over extended periods of time.

Print selection
Drop selection is achieved through a simple electrostatic approach to drop charging. A solid mass charge plate is aligned linearly with the array of droplets. Charge voltage is applied at a fixed frequency. Using the precision of the CMOS in the silicon nozzle plate, the droplets are phased to this charge voltage. At the approximate time a droplet is formed in front of the charge plate, an opposite charge is applied to the droplets. This charge creates a deflection of the droplet to a grounded surface so that the drops can be captured and recycled through the continuous inkjet system. If the phasing (timing) of the drop break is changed to where there is no charge on the plate, then the associated drop is uncharged. Uncharged drops do not deflect, becoming the print drops that fall directly to the substrate to produce an image. This alternating of charge and uncharged droplets creates a binary digital printing technique that produces a print rate of over 200 kHz, the highest of any inkjet technology (see Figure 4).

UltraStream technology is configured to take advantage of industry-leading droplet generation rate to produce an image using 600 dpi in the paper cross-track direction and 1800 dpi resolution in the paper direction, with sub four pico-liter droplets. This resolution equates to image quality equivalent to 1200x1200 dpi at speeds of over 500 ft per minute (152 metres/minute).

Inks and substrates
In addition to precise drop generation and print selection, achieving the highest level of image quality requires Kodak’s proprietary micro-milled pigment inks. These innovative pigments produce a consistent and narrow distribution of nanotechnology particle sizes compared to conventional pigments. Environmentally-friendly water-based inks use these nanotechnology pigments to produce a colour gamut larger than offset inks. This is achieved through the transparency of the inks, which allows light transmittance reflecting from the substrate through the ink lay down. In addition, Kodak’s pigment inks provide durability on the substrate, remain waterfast, and resist colour degradation from the sun’s rays for decades.

Along with UltraStream technology, Kodak is innovating pigmented inks to expand colour gamut with five, six, or seven colour stations for more demanding applications. With the use of low-cost substrate treatments and chemistries developed by Kodak, it is possible to achieve a broader substrate range than most water-based pigmented inks. The low humectants in Kodak’s proprietary water-based inks enhance drying, offering better compatibility on otherwise challenging substrates. Substrates include a variety of coated and uncoated papers—including glossy—as well as flexible packaging materials like oriented polypropylene and other impermeable materials like vinyl.

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Benefits of UltraStream
The UltraStream provides a reliable, high-volume production system, proven through a legacy of continuous inkjet technology and Kodak’s first generation of Stream inside the Kodak Prosper product lines. Prosper has been proven on the market for over seven years, producing over 90+ billion images per year. UltraStream promises to enable 24/7 production. The steady state ink flow provided by continuous inkjet prevents nozzle jet- outs and clogging, enabling exceptional printhead life that is agnostic of image coverage and speed. Typical DoD systems require constant nozzle wetting, which reduces uptime and wastes ink, and inkjet heads reduce life as ink coverage and speed increases.

The UltraStream creates uniform droplets with precise drop placement accuracy, due to high drop velocity generated through the nozzle under pressure. This allows the nozzle plate to be protected from the substrate, reducing sources of contamination that decrease printhead life. UltraStream prints are satellite free. Unlike DoD, which prints with significant background scatter, UltraStream print is clear and crisp with no extraneous dots. Kodak’s pigmented inks are manufactured internally through efficient processes, leading to the lowest-cost inks on the market. In addition to its many performance benefits, pigmented continuous inkjet technology is green, and printhead refurbishment enables reuse of nearly all of the components in the assembly.

Applications
Given the superior image quality, unsurpassed productivity, and compelling economics, Kodak UltraStream is poised for broad market penetration in both graphic communications and industrial applications. Traditional inkjet markets, including publishing and commercial applications, will attract an even greater share of page volume migration as UltraStream delivers on the unmet market need for high-definition print quality. The precise dot placement accuracy was developed to target higher-end print applications, such as magazines and catalogs. This segment has long awaited a solution that offers flexibility and personalisation without compromising image quality — and UltraStream will deliver.

The boundaries for this technology extend into industrial applications as well. Home décor markets require a wide-format solution with virtually limitless print runs and reliable colour match from lot to lot. UltraStream delivers that and more. Compared to DoD printheads, which experience starvation or air ingestion causing a disruption in the ink flow that requires print speed adjustments, continuous inkjet delivers consistent, high- speed productivity at any coverage level. Additionally, Kodak’s proprietary nanoparticle inks offer superior colour gamut and low metamerism due to the combination of transparent, nanoparticle ink layers and the close-to-ideal spectral curves of CMYK colourants.

The technology will co-exist in the market along with Kodak Stream technology to offer different platform options, addressing the needs of each application.