Latex Printing: Hope or Hype?

When the wind blew from the west, drifting over the roof of RR Donnelley’s old Chicago Division as massive presses churned out Sears catalogs, I still can recall the foul, chemical odor of toluene more than two decades later. Similarly, as pungent fumes waft quickly up the nostrils, walking into most wide-format shops that deploy solvent printers may bring to mind a different kind of vinyl and a 1977 Lynyrd Skynyrd southern rock tune: “That Smell!” But customers and workers at the Big Print Shop, Benton City, WA, cannot relate to such a toxic, odiferous experience.

That’s because the small, dozen-employee firm, celebrating its 20th year in business in 2013, never has had solvent printers on its production floor. The company, owned by Jack and Kelly Edwards, was started in 1993 to provide marketing support for Hewlett-Packard, which is still one of its major clients. “We’ve stayed away from solvent,” explained general manager Ron Morris. “It’s just not safe for the environment, and that smell … is repelling.

“Customers walking into our shop can watch the printer print without wearing a mask,” Morris noted. “It smells clean and fresh in here,” just like the Pacific Northwest should. When the HP customer took delivery two years ago of a Designjet L25500, the 60-inch latex device began to open new doors to outdoor signage and banner business, he said.

And nothing stinks because HP Latex Inks produce virtually odorless prints. The water-based inks are nonflammable and noncombustible and, unlike many “eco-solvent” inks (see sidebar), they do not require hazard warning labels and contain no hazardous air pollutants. Additionally, no special ventilation equipment or external dryer is required for safe and productive operation, helping to keep energy costs down.

“Previously, it was all aqueous-based [output] that we had to [then] laminate,” Morris added, noting that the newer UV inks now available are better, especially from a fading perspective. Still, Morris and Big Print have no regrets about choosing the latex route. From nearly zero percent in late 2010, banners and outdoor signage now account for some 60 percent of Big Print Shop’s work – an impressive growth rate that is still climbing, the GM reported. Some 95 percent of these jobs, he added, are extremely small quantities, even one-offs of birthday and anniversary banners, for example.

Most importantly, Morris stressed, customers are elated with the vibrancy of the prints as well as with turnaround time and service. With its latex printers, Big Print doesn’t have the same drying demands as its solvent competitors do. “We just did a same-day turn on a 5x30-foot, full-color banner with glued edges and grommets,” he said proudly.

Profiting from Aqueous-Dispersed Polymers

What is so-called latex ink? In HP’s case, its viscous latex inks are pigmented, water-based inks using aqueous-dispersed polymer (“latex”) technology. In addition to being odorless, they have very low levels of volatile organic compounds (VOCs). Latex inks are ideally suited for wide and super-wide applications, including event banners, transit signage, and other outdoor applications as well as for high-quality indoor signage, according to HP.

For Big Print Shop, the additional profits from these types of product additions have been so good, in fact, that this past July, the firm expanded its 10,000-square-foot operation, opening a second location (2,800 square feet) in Richland, 13 miles east. “Window clings are huge for us,” Morris said, “especially in the hospital and hospitality space, and one-view perforateds are popular among restaurants. We can do backlits now, too.”

To keep up with increasing demand, the firm also purchased two Designjet L26500 printers, the new 61-inch-wide model – one for each location. “The numbers supported our expansion,” Morris explained. “The printers have accounting cost calculator built in,” making it painless and easy to track ink and media costs for each job. Big Print Shop produces trade show displays, marketing materials, textile printing, adhesive vinyl wraps, and wall coverings, too, offering two-day turn-around on banners and banner stands. Its new Richland shop already is becoming a favorite among local artists who want to produce high-quality reproductions and prints, Morris added.

Also in October 2011, HP introduced the 104-inch-wide Designjet L28500, which delivers speeds up to 70 percent faster than the L25500. The L28500 and L26500 produce 1,200-dpi output with outdoor display permanence of up to three years, unlaminated (five years, laminated). The output also dries inside the printer, boosting productivity for double-sided print jobs and allowing for immediate finishing or use.

Both new systems also feature new HP 792 Latex Designjet Inks, which produce rich blacks and glossy results on banners and self-adhesive vinyl, and offer double-sided printing capabilities with less user intervention and more accurate, automated registration. Compatible with more than 500 media solutions, including the new HP Double-sided HDPE Reinforced Banner material, HP latex inks provide a consistent, reliable performance across a variety of substrates. Ink chemistry and HP’s wide-scan, 12-picoliter thermal printheads combine to produce vivid, durable prints on a variety of coated and uncoated materials, including most low-cost, eco-solvent/low-solvent compatible media.

In addition, HP Latex University started up about 15 months ago as well. The set of training materials and application workshops is led by industry experts. There’s also the Ecosolutions Trained Printing Company program for educating HP Latex Printing Technologies users in sustainability best practices.

“With about 13,500 HP Latex Ink systems installed worldwide, HP is offering a superior alternative to eco-solvent solutions that delivers the versatility and ease of use our customers demand while lowering their impact on the environment,” said Xavier Garcia, vice president and general manager, Large Format Production and Industrial Business, HP. “By allowing customers to cost-effectively print a wide array of new applications and providing the training required to succeed, our updated HP Latex portfolio helps PSPs differentiate their businesses and seize new growth opportunities.”

Mimaki, Ricoh, Too

Mimaki introduced a new latex printer 11 months ago, in February 2012: With a print speed of up to 60 square feet per hour, the JV400-130/160LX delivers maximized performance with a proprietary RasterLink6 RIP, enabling three ink layers in one pass with white and color inks. Exceptional quality is ensured by a minimum dot size of four picoliters (pL) and the ability to use variable sized ink dots for smooth gradation without a grainy appearance.

The OEM showed its new wide-format inkjet printer, equipped with the world’s first white latex ink, at drupa last spring. The firm demonstrated the printing of window graphics and 4-color posters printing using ordinary transparent film or paper, not dedicated inkjet media. It also can print on uncoated substrates.

The JV400-130/160LX supports six colors plus white. Mimaki's white latex ink meets the needs of a range of printing requirements and substrates. It can be used with transparent PET, window decoration, and shatterproof window film. The JV400-130/160LX is equipped with Mimaki's MCT (Mimaki Circulation Technology) ink circulation system that prevents pigment sedimentation for stable ink dispersion and a reduced need for manual ink cartridge circulation processes.

Mimaki latex inks are fast-drying, and the drying process is additionally supported by three heaters integrated into the printing system (pre, print and post heaters) as well as fans that ensure products are ready for processing and finishing as they exit the printer. A low curing temperature of 140 degrees F or below also enables printing on a wider range of heat-sensitive substrates.

This past September, Mimaki showcased the eco-friendly attributes of the JV400-LX system at the EcoPrint Europe Live sustainability show in Berlin, Germany. The revolutionary inkjet printer combines the flexibility of a low CO2 footprint and high-quality printing. Mimaki Latex inks have received full HAPS certification and contain no pollutants. Prints exiting the printer are completely dry and ready for immediate post-processing.

Also at the EcoPrint, Ricoh showcased some of its technology including the Pro L4000 featuring next generation piezo-electric print heads, latex inks, and a 7-color ink set: CMYKcm+white. Available in two sizes – 54 and 64 inches – the L4000 offers multiple jetting printhead technology to produce three different drop sizes simultaneously (as small as 4 pL) and output speeds up to 195 sq ft/hr. Slated to be available in North America and Europe in Q1 2013, it offers extensive media support on a range of substrates, Ricoh reported.

The Semantics of Marketing

When is eco not ecological? Anything with the word water in it sounds “green.” Solvents contain chemicals. In scientific terms, the word solvent is derived from the Latin solvo, “I loosen, untie, I solve.” So a solvent is a substance that dissolves a solute -- a chemically different liquid, solid or gas -- resulting in a solution. Solvent ink is a relatively inexpensive type of ink made to work in inkjet printers. In the world of ink, the term solvent is used to mean any ink that is not made with a water base; solvent inks are pigment inks.

In the not-so-distant past, most display media was made of vinyl, and the solvent in the inks used to print them helps the pigments bind with the vinyl. This binding makes the printed outdoor display durable enough to render them impervious to the elements and not easily fade.

By contrast, water-based inks are dye inks. The rap on aqueous- or water-based inks used to be their lack of durability. But that changed about five years ago, when the durability of latex prints improved along with image quality.

‘Eco-solvent:’ In the middle

Somewhere in between water-based and solvent inks, eco-solvent is a form of the non-water based ink that is made from ether extracts taken from refined mineral oil. However, the cognitive implication of the term “eco,” which brings to mind the idea of an ecologically sound product, is an inaccurate assumption when applied to this form of solvent ink, according to the website Neither the material used in making it nor the creation process are ecologically conscious choices.

Eco-solvents also are known as soft or mild ink, and as such they are bogged down by slower dry times and the not-so-ecological need for multiple heaters in the printer.

A primary benefit of HP latex ink is not having to wait 24 hours before it is fully dry, as FLAAR Reports pointed out: “With solvent inks, they may be dry to the touch but are not completely dry until 24 hours. If you roll-up a solvent print for shipping, it will outgas and stink with a wretched odor once you install it even weeks later (since the pent-up smell of the solvents do not dissipate if the material is rolled up tight).”

But HP latex ink are stated to be fully dry once they leave the printer. In theory, prints could be laminated immediately. HP Designjet and HP Scitex Printers with latex inks use internal radiant heaters and forced airflow to cure the inks inside the printer to produce dry, ready-to-use prints.

Reproducing Michelangelo’s “Creation of Adam” with HP Latex

Osmand Signs of Auckland, New Zealand has been in business since 1954, specializing in vehicle wraps and building signage.  The company recently completed one of the most unusual jobs in its near 60-year history. Client Samsung challenged the boutique shop to deliver a 19.6 ft. x 44.2 ft. reproduction of Michelangelo’s “Creation of Adam” on a brick wall in the heart of Auckland’s central business district.

“The twist with this job was to paint over the mural with the same color as the bricks to conceal the image,” says Keith Ellis, one of two directors who run the business. “They wanted us to erect the mural and then paint over it so they could do a slow reveal to make it look like someone had actually painted the image directly onto the bricks. That’s how good the quality is with the HP Latex prints. The print really looked like a painting and our client was impressed with the final installation.”

The mural was printed on an HP Designjet L25500 Printer with HP Latex Inks using Arlon 6000XRP vinyl substrate and a matte laminate. Printed in 12 drops, the sign was applied to the brick wall and painted over with washable acrylic paint.

It took Michelangelo four years to paint the ceiling of the Sistine Chapel and the “Creation of Adam” is one of the most recognized images of his masterpiece. Osmand Signs printed the 12 panels over an eight hour shift and installed the following day.

“It was quite an original concept,” adds Wade Blow, the other director of Osmand Signs. “Once our client had finished with the image the building owner suggested we leave it.. He felt it enhanced the building, which is in a prominent area in Auckland. The vibrancy of the image and size of the installation has been a good promotional vehicle for us and delivered new business.”

Osmand Signs installed the HP Designjet L25500 Printer in November 2010 and reports a 50 percent productivity increase with the jobs it runs on the printer. Says Blow, “the printer has proven its worth by dramatically reducing the time it takes to complete jobs. There’s no waiting for de-gassing with the prints. We can print, apply and finish off immediately. We have literally doubled our output speed and, as a result, have been able to take on more work without having to increase shifts.”