Inks for Flatbeds
UV Spreads into the Segment
By Kim Crowley
Flatbed printers bring new opportunity to print shops, allowing them to print innovative graphics directly to rigid materials such as plastic, foamboard, metal, tile, and glass. Hybrid options provide the opportunity to print on roll material for posters and vehicle wraps.
As technology advances, more print providers turn to flatbeds that utilize UV technology. According to I.T. Strategies’ 2009 forecast, UV ink is a growing technology segment, with revenues expected to increase from $1.6 billion in 2008 to $3.2 billion by 2013, a compound annual growth rate (CAGR) of 15 percent. Low-end flatbed UV inkjet printers continue to be the largest segment of the UV inkjet printer install base, growing from 5,048 printers in 2008 to about 9,637 by 2013, a CAGR of 14 percent.
UV printers use an ultraviolet lamp—typically mercury—to cure ink onto the substrate almost instantaneously. Some models now use low-heat and low-energy light emitting diode (LED) lamps to cure UV ink.
Randy Paar, display graphics product manager, Océ North America, says that flatbed users prefer UV technology. "Once the printhead deposits the ink swath on the substrate, a special UV lamp follows and cures—hardens then dries—the ink. UV inks adhere to nearly any substrate—either rigid or flexible. Unlike aqueous printers, UV printers can print on inexpensive uncoated paper and substrates," he says.
Ink AdvancementsUV-curable inks also ease environmental, health, and safety concerns. "UV inks produce very low volatile organic compounds (VOCs) and do not require special ventilation to meet occupational exposure limits. With rapid curing, vivid colors, excellent outdoor durability, and hardness and adhesion on non-treated media, UV-curable inks are an ideal solution for outdoor signage to indoor graphics," says Don Knox, U.S. director of sales, large format printing, Graphics Solutions Business, Hewlett-Packard (HP).
Knox also notes that because UV inks cure with light exposure they do not require large drying systems, improving workflow and saving space.
UV inks continue to advance. "VUTEk QS2 and GS series inks represent our sixth generation of inks. They provide additional durability so you can score, cut, and bend printed output without chipping or cracking," notes Ken Van Horn, product marketing manager, EFI VUTEk.
EFI is now shipping the 3.2-meter GS3200 hybrid UV flatbed printer. Van Horn explains how EFI continues to participate in the transition from solvent to UV and witnessed the shift within the last 18 months, where solvent purchases slowed in favor of UV. "Expanded applications and the economics of direct to substrate printing are certainly contributing to the rapid shift to UV flatbed and hybrid printers. As people started to embrace flatbeds and UV, solvent declined in the market. UV became the predominant technology," he says.
Of course the environment is one driver of UV popularity, but Van Horn doesn’t think it’s the main reason. "The environment might be a catalyst behind it, but realistically, I think it’s the economics and flexibility that you get from UV inks. Users have the ability to print directly to multiple substrates, with a much faster turnaround time, because you don’t have to wait for the ink to out-gas or cure—it instantly cures when it goes down onto the substrate."
Any flatbed ink should feature good abrasion resistance, coverage, and high color strength to perform well. "The ink has to adhere on substrates which are not specially treated for digital printing. In our opinion there are only two kinds of inks which fulfill this requirement—UV and SEPIAX inks," says Karl Heinz Ebner, marketing and sales director, SEPIAX Ink Technology GmbH. SEPIAX develops and produces water-based pigmented inks featuring high water and abrasion resistance, up to three years of outdoor stability, and are odorless.
Inks On BoardAgfa Graphics’ :Anapurna engines use free radical UV inks specifically designed and manufactured by Agfa. "Adhesion is excellent; there are very few man-made substances that the ink won’t stick to well. It also has tremendous outdoor weatherability. Our inks stand up to normal outdoor conditions for up to three years without any visible color shift," says Michael White, wide format manager, North America, Agfa.
:Anapurna flatbeds use two UV lamps with two settings—full and half power—to cure :Anapurna M UV ink. The UV lamps can be changed by the operator to help keep costs to a minimum.
The new :Anapurna Mw features a fully separated white ink management system, circulation system, under-pressure-regulation, and cleaning circuit. In addition, the white ink tank is equipped with a stirring mechanism to keep the ink properly mixed at all times. Shown at this year’s SGIA in October, the :Anapurna Mw’s white ink allows for printing on dark substrates and backlit and frontlit displays. White is also used as a spot color and a base layer to create a wider gamut of colors.
CET Color’s flatbed printers use UV ink that cures with UV mercury lamps. The ink is rated for two year outdoor durability and high abrasion resistance. The latest CET flatbed printer, the X-press F5126Z, features 16 Konica Minolta 512 14 picoliter printheads and a six- by ten-foot table. The printer features eight channels supporting white, varnish, and spot color applications.
Durst Image Technology US LLC’s Rho 800 platforms use Durst’s UV ink set. Christopher Howard, VP of marketing and sales, Durst, says the inks offer extremely good adhesion on a wide variety of roll as well as rigid material, including more difficult substrates such as acrylic and Coroplast. The Rho 800 HS builds on the success of the Rho 800 Presto platform. The HS version features newly designed Quadro Array technology, which offers a speed increase of 80 percent from the Rho 800 Presto.
Howard adds that the technology in Durst’s UV ink set allows for both highly reliable jetting and print operation as well as the adhesion characteristics necessary for rigid substrate production. "The importance of the jetting characteristics is paramount for us to retain the reliability of the Quadro arrays and not have an issue with dropped nozzles, which can lead to printer downtime for purging. This is a key factor in the productivity equation that the Rho printers offer," he says.
Each EFI printer features its own UV ink set based on the unique capability of that device. Purity is one of the characteristics that Van Horn says makes EFI inks stand out. "Our inks are manufactured with the best pigments and milling processes. It really leads to a much higher performance ink, which jets better through the printheads." He also says that color, performance, and durability are very consistent from batch to batch. "A lot of ink manufacturers can’t say that," he states.
Gandinnovations flatbed printers use UV inks manufactured by the company. Customers can select from a glossy UV ink, a standard UV ink, and a Flexform ink that can stretch up to six inches when heated and molded. The company unveiled the Flat-to-Roll (FTR) option for the 1224 series of Jeti UV flatbed printers in September. The FTR is fitted onto the front and back of the printer while in production and performs as a hybrid.
An accelerated weathering machine is used in Gandinnovation’s demo room to test each ink, although Cory Brock, director of marketing, Gandinnovations, notes the lifetime of the ink depends on the substrate it is printed on. "We pride ourselves on the adhesion of the ink and a high scratch resistance. We know that during an installation, things can get complicated. We don’t want our inks to be another problem that installers have to worry about," says Brock.
GCC offers a total solution to address any possible ink adhesion issues. "For special substrates which could cause UV ink adhesion issues—ceramic tiles, acrylic, glass, stainless steel—GCC provides pre-coat image printing and then a top coat," says Lisa Hsu, senior specialist, GCC. A unique primer, based on the media used, is applied to enhance ink adhesion, then the job is printed. Afterwards, a top coat is added to protect the image surface. GCC’s new StellarJET K72UV premiered in Europe at FESPA Digital. A new conveyor flatbed roll-to-roll handling system allows it to print on a variety of materials.
Gerber Scientific Products, Inc.’s (GSP) flatbed printers use GerberCAT inks, a four-color cationic UV ink set that cures at approximately room temperature. GerberCAT cationic UV ink is proprietary to GSP. "Unlike solvent inks that create a chemical bond by eroding the surface of the substrate, GerberCAT inks cure into a strong, yet flexible mechanical bond that provides output that is immediately usable," states Curt Brey, executive director digital solutions, GSP.
Gerber’s curing process is provided by Cold Fire Cure, the company’s unique and proprietary light source designed by Gerber for the Solara ion to cure GerberCAT cationic UV ink. Cold Fire Cure works at an extremely low temperature, allowing Solara ion printers to print on many environmentally friendly products such as recycled paper products, and the UV light provides a minimum of 3,000 hours of useful life.
GSP’s Solara ionZ is a high-resolution cationic UV inkjet printer. It offers the same technology as other printers in the Solara ion family, like the proprietary GerberCAT cationic UV inks and the low temperature Cold Fire Cure system, but also features eight printheads that fire 14 picoliter ink droplets. The smaller size allows the Solara ionZ to generate higher print resolution and near-photographic quality.
HP’s flatbeds use UV-curable inks, with the exception of the HP Scitex FB6700, which uses HP Scitex WB300 Supreme water-based pigmented inks. HP UV-curable inks have two year outdoor durability, and are water- and abrasion-resistant. "The high level of transparency inherent in UV inks produces a very clean color gamut, resulting in vibrant, colorful displays, signs, and graphics," notes Knox.
HP Scitex WB300 Supreme water-based pigmented inks have a two-year outdoor durability for UV-resistance; they are water- and abrasion-resistant; and they don’t crack when folded because they are flexible.
HP offers a range of flatbed printers from entry-level to high production. The HP Scitex FB7500 printer, launched at SGIA in 2008, features speeds of up to 5,380 square feet per hour and a low cost per sheet. HP Scitex X2 drop on demand piezoelectric inkjet printheads support resolutions of up to 500 dpi and use HP Scitex FB220 UV inks, which require no large drying systems and produce very low VOCs.
Mimaki USA, Inc.’s JF series of flatbeds use both rigid and flexible inks. LF-200 Flexible UV ink features high elasticity and LH-100 Hard UV ink offers high scratch resistance and chemical resistance. "Rigid inks have a slightly higher color gamut and UV resistance to fading. The flexible inks stretch over 200 percent," says Steve Urmano, marketing director, Mimaki. The flatbeds feature inks that are cured with either UV or LED lamps. The JFX-1631 flatbed is now available to the U.S. market. The printer features a roll-to-roll option, a maximum print width of 63 inches, and resolution up to 1,200 dpi.
Mutoh America, Inc. manufactures Mubio corn-based solvent ink for use with the ValueJet 1608HA flatbed printer. The ink satisfies those who seek an environmentally friendly solution. It is made up of 80 percent plant-derived substances, with all ingredients approved by the U.S. Environmental Protection Agency’s Design for the Environment Program, and it has no harmful VOCs. Mubio ink dries using two heated air nozzles on each side of the printhead. Jeff Springan, product engineer, Mutoh, says that the ink holds up to the rigors of large format digital print applications nearly as well as eco-solvent inks.
The company’s best-selling flatbed printer is the 64-inch ValueJet 1608HA. Recent enhancements include an improved printhead, re-engineered media tables for greater strength and stability, and an integrated hot air drying system.
Océ Arizona series printers use UV-curable CMYK inks with seven ink drop sizes ranging from six to 42 picoliters. A White Ink Option is available on the Océ Arizona 350 GT and Océ Arizona 350 XT models.
Océ recently released Océ IJC256 UV-curable inks for the Océ Arizona series of UV flatbed printers. The new ink formulation offers improved adhesion to most rigid plastic media such as polystyrene, acrylic, and foamed-PVC, and to coated banner vinyls and self-adhesive vinyls. It is best suited for outdoor applications. "Our new Océ IJC356 inks were formulated to provide improved adhesion and resistance to chipping, and are intended for applications where printed pieces are cut or routed through the printed areas, or used outdoors," notes Paar.
A Future for Solvent?With increased attention to the environment, there are mixed opinions on the future of solvent inks in the flatbed space. "Some graphics manufacturers prefer the solvent look over UV inks," Brock says.
"Solvent technology will continue to be used in this space at least in the near-term, but its use is clearly declining with the advent of more environmentally friendly ink technologies both in terms of printed volume and printer sales," states HP’s Knox.
"Solvent-based inks have the great advantage of cost, high productivity, and durability levels," states Amnon Shalev, product manager, Bordeaux Digital PrintInk Ltd. "Having said that, the range of rigid media which can be used with these inks is limited." Shalev says that Bordeaux offers a partner program and cooperates with OEMs in developing specific applications or competitive high-quality inks. As with other UV-curable inks, Bordeaux’s PLASMA inks contain acrylates, which polymerize when exposed to UV light.
"Bordeaux offers Mix&Match capabilities, making the ink changeover process smooth and effortless yet saving money on ink and running the printer. In the case of UV-curable inks, a qualified engineer should be involved in most ink interventions; in the Mix&Match changeover scenario the time and cost of an engineer is saved. Bordeaux inks offer the same performance level for less cost," states Shalev.
Agfa’s White states that solvent inks are on the way out. "There are too many benefits that UV inks offer—no VOCs, fast curing resulting in high productivity, sharp vibrant colors for indoor and outdoor applications, good fade resistance, chemical and abrasion resistance, and excellent adhesion on a wide variety of rigid and flexible, coated and uncoated substrates," he explains.
Third Party InksSavings can be found using third party inks, but they may bring the risk of negating warranties.
Agfa does not approve any third party inks for its engines. White explains that :Anapurna M inks are specially formulated for use in Agfa’s :Anapurna printers and are made to work with Konica Minolta printheads to render the best quality output. "In addition, our inks feature an open nozzle time of up to five days without clogging. Ink is essential to Agfa’s technology—the :Anapurna engines are optimized when used with our inks," he says.
Durst works with other ink manufacturers for special products and processes. "3M Graphics Market Center is one manufacturer who offers an ink set and materials for the Rho roll printers. Customers participating in 3M’s program may have a specialized printer for the production of traffic signs which requires a unique ink set only available from 3M," states Howard.
EFI VUTEk printers are eligible for extended warranties when used with VUTEk inks. The company also has a unique relationship with 3M through which they warranty the printers with 3M inks.
"It’s extremely difficult for us to warranty a printer and to guarantee the operation of the printer, specifically with a third party ink delivery system in the printhead—with the exception of our partnership with 3M. We don’t have the ability to test all of the third party inks in the marketplace and learn how they are going to perform. We don’t know what they are going to do to the printheads or to the ink delivery system," explains Van Horn.
Gandinnovations occasionally tries running third party inks in their printers as favors to our customers and for testing purposes. "In recent years we found we are more comfortable with our inks, just because we know the printers so well inside and out," says Brock.
Océ works closely with ink manufacturers to ensure formulation is optimal for the company’s printers, and they do not recommend the use of third party inks not sold by them directly. "Ink manufacturers are typically selected by Océ early in the product development stage and together we define an appropriate formulation that meets our standards," explains Paar.
"The alchemy of the printhead and ink work together to create the end result, in this case a print—the item that generates revenue for the customer. If that item fails, the customer wants it fixed quickly, and the added element of a third party during troubleshooting only slows the recovery process. Using only Océ-branded inks in Océ Arizona printers makes sense," he adds.
Advancing FlatbedsInk continues to evolve. As research and development efforts heighten we see a richer color gamut, quicker drying and curing, more outdoor UV and abrasion resistance, and heightened response to environmental and safety concerns.
Flatbed printers allow shops to print directly to rigid substrates, eliminating mounting steps, creating application possibilities, and enhancing production. Manufacturers continue to craft affordable products that drive efficiency and expand capabilities.
Dec2009, Digital Output