By Melissa Donovan
Variations of ink are common. UV can be UV-curable or UV LED. Solvent is divided into eco-solvent, low solvent, mild solvent, and even a solvent UV—or SUV. Latex is considered aqueous. Sublimation and fixation inks—common for textile printing, but also used to print to hard surfaces—are categorized as disperse dye or acid dye, reactive dye, and pigment ink, respectively.
Each ink type is effected by similar trends. Customization and media compatibility are in demand. Buyers want an ink that offers cost-effective, on demand print capabilities on a variety of substrates. Ink sets are formulated and reformulated to meet market demand. The end result are a number of ink chemists working diligently to keep up with the current and future needs of the graphic arts.
Progressive and Established
There are differing opinions on the most commonly used ink type. Traditional chemistries like aqueous and solvent remain prevalent while UV and textile-based ink sets are up-and-coming forces. Conflicting views illustrate the variety of ink suppliers.
Aqueous is an established ink and latex is included in this category. John D. Peterman, EVP sales and marketing, Big Systems, LLC, believes its popularity remains strong because it matches up with some of the most affordable printing equipment—in addition to an ever-expanding range of printable wide format materials.
“Within the inkjet market, aqueous is the largest by both volume and end user value. The broadening range of applications that can addressed by this ink, coupled with favorable environmental and safety profiles, means that aqueous continues to be a favored ink class,” agrees Hamid M. Shirazi, global technical promotions manager, Fujifilm Imaging Colorants, Inc.
Solvent and its more environmentally friendly iterations offer staying power, mainly for their outdoor durability. “Of course, solvent ink has two issues which aren’t ideal—the smell of the ink and dry time. However, it continues to improve upon these concerns. Most notably, the emergence of eco-solvent inks with lower odor and faster dry times,” says Jun Kurokawa, technical marketing engineer, OKI Data Americas, Wide Format Division.
Eco-solvent ink provides the best of both worlds—the quality of solvent with environmental safety features. According to Vernon Jones, manager, marketing and promotions, Mimaki USA, Inc., this ink is becoming a preferred choice due to its capability to produce high-resolution printing on an economical scale. “It does not produce fumes, therefore, the low carbon footprint is regarded as environmentally friendly compared to heavy solvent ink. Eco-solvent ink is highly durable, making it ideal for fine art reproduction, wall décor, vehicle wraps, and outdoor displays.”
While aqueous and solvent—and the ink types that fall under those headings—remain, some of the biggest growth reported in ink usage falls in the UV category. Heather Rockow, UV business development manager, Collins Inkjet, cites the company’s UV/LED ink sales growing over 100 percent from 2013 to 2015 with LED growing faster than UV.
“Our estimations are that UV is growing at a rate of approximately six percent and has the dominant share of today’s inkjet market. And as UV achieves greater flexibility, its growth will accelerate,” foresees Deborah Hutcheson, director of marketing, NAFTA, Agfa Graphics.
Demand continues to rise as the newest UV formulations offer faster drying speeds and adhere to a wider range of media. “For printing to soft signage fabric, other than dye-sublimation (dye-sub) to polyester, new foldable and stretchable UV-curable inks printed to polypropylene are showing huge growth,” shares Craig Reid, VP/GM – digital division, INX International Ink Co.
UV LED effects this category’s steady increase. According to Guy Cipresso, VP sales and business development, Novus Imaging, Inc., UV LED cure inks are fast becoming a popular choice due to low curing temperatures and long lamp life. He cites analyst firm InfoTrends, which estimates the high end of the UV equipment market will grow by a compound annual growth rate of 6.3 percent.
“LED inkjet is perhaps the fastest growing segment, because printing companies and their customers want many of the benefits LED offers in terms of reduced energy usage, a ‘greener’ operation, and broader substrate versatility,” agrees Stephen Emery, VP, ink and Jetrion businesses, EFI.
Dye-sub and other textile-based ink technologies including disperse, pigment, reactive, and acid, are prevalent. Aaron Blank, business development manager, Alpha Ink Jet, sees dye-sub and reactive as the two segments in this category being used the most. He cites cotton costs as a direct reason. Escalating after 2010, the price change forced clothing manufacturers and designers to look for alternatives.
“For those wanting to print digitally to cotton, they needed an inexpensive ink alternative. Therefore, we saw a rise in reactive dye usage. It is easy to use, widely available on all printhead types, and gives you a very large color gamut,” he continues.
Matt Gusse, VP sales and marketing, Advanced Color Solutions (ACS), admits that as a company, ACS sells five times more digital sublimation ink compared to both eco-solvent and UV. “The visibility and access to information regarding dye-sub is more available across multiple marketplaces. Dye-sub has grown into a standard in the lineup of decorating and printing both hard and soft substrates and is no longer limited,” he adds.
Trends of Customization and Compatibility
Multiple trends drive ink usage. Customization and media compatibility are the biggest influencers.
“The fundamental drivers for overall digital print include the increasing need for economic short runs, personalization, and improving the agility of supply chains to respond to end customers. These fundamentals underpin many markets,” admits Fujifilm’s Shirazi.
According to Collins’ Rockow, “as retailers strive to meet consumers’ hunger for individualized products, digital is the only answer. Consumers aren’t just asking for signs and point of purchase displays, now they want toothbrushes, diapers, athletic shoes, and airplane interiors custom printed.”
Décor is part of that list. “The textile inkjet market came into the U.S. from Europe. Décor printing is growing. Its effect in Europe will likely expand to the U.S. or other countries in the not too distant future,” explain Taka Suzuki, marketing manager, advanced material division, and Stevie Washio, technical manager, digital ink, Toyo Ink America, LLC.
This is not limited to fabric—take for example untraditional substrates like glass. “The major demand in construction glass is divided between interior and exterior applications. These trends are driven by designers/artists and architects. On the graphic aspect we notice increasing demand for textures, patterns, and different material imitation on glass. The functionality aspect of the printed glass is highly important for the consumer—light diffusion and light transmission energy efficiency. Moreover, there is an increasing demand from the interior sector for durable photorealistic images,” recommends Shimrit Marom, director of corporate marketing, Dip-Tech Digital Printing Technologies Ltd.
Not only do buyers request customized products, they expect graphics to be high quality. “Trends that are affecting ink usage are the desire for full coverage prints and photographs which require higher ink saturation,” suggest Tamara Pitman, product manager, and Kristina Devine, senior marketing and pricing specialist, Coveris Advanced Coatings.
“The trend is definitely towards higher definition imaging even in grand format printing. The move from analog to digital for a number of applications including packaging prototypes and short runs is one factor. Digital compresses packaging lead times from design to shelf and can be easily adapted to regional campaigns,” agrees Novus’ Cipresso.
Flexibility between ink and media is an important consideration. “The biggest trend is the need for inks that adhere to a range of substrates—both rigid and flexible materials—on much faster presses. Price is always a factor for our customers, but it is balanced by the application of the ink on many substrates,” shares Peter Saunders, business director – digital, Sun Chemical.
Specifically, “the ability to offer customers a multitude of different printed substrates and effects is driving the shift to UV,” adds Adam Larson, global portfolio manager – premium films, 3M Commercial Solutions.
“Pigment ink that knows how to print on all fabrics and in one simple process is just the answer for short turn-to-market cycles that are dominant in textile printing. One ink that prints on cotton, blended, polyester, viscose, silk, leather, and décor and in one printing line—any textile printer, dryer, and take-up unit to the roll the fabrics, will open new business opportunities,” points out Nufar Kiryati, marcom manager, Bordeaux Digital PrintInk.
Versatility doesn’t stop at media. Nitin Goswamy, president, A.T. Inks., says the trend is towards multi-platform inks. “Inks that work in more than one printhead, which allows a print shop with multiple models of printers to keep inventory of just one ink that can be used across all of their printers. The demand is almost always derived from print shops that need innovative solutions that allow them to function more efficiently.”
To meet demand from print providers and even their customers, for a high-quality ink that enables customization and media versatility, ink chemists must adapt existing formulations or invent new ones.
Specific features are apparent in these reformulations, like “larger color gamut and more robust weathering properties,” explains David Conrad, director of sales and marketing, Mutoh America, Inc.
“Inks may be specially formulated or reformulated to meet regulations in place for specific regions. They are also often reformulated to improve attributes like richness of color, opacity, and outdoor durability,” adds Lily Hunter, product manager of textiles and consumables, Roland DGA Corporation.
Adhesion and reliability are also addressed. “Manufacturers have to be innovative to solve all of these challenges. It seems we are more restricted in terms of raw materials because of the suppliers’ rationalization, the demands of the printheads—which allow us to use less materials, and the environmental concerns that do not allow us to use some materials,” admits Pedro J. Martinez, CEO, Afford.
Kristen M. McNamee, technical manager – MCS/PG warranties, inks and clears, 3M, agrees. “New raw materials and increasingly discontinued materials are forcing formulation changes while attempting to maintain or improve on overall performance characteristics. Growing in importance is increased sustainability awareness globally and how ink formulations affect the environment.”
Jack Papaiacovou, director of product development, Hilord Chemical Corporation, provides reformulation examples specific to ink type. “More ink manufacturers are reformulating dye-sub inks to accommodate grand format printers. On the same token, printer manufacturers are designing faster printers that can be used with water-based, dye-sub inks.”
And for UV-curable inks, newer formulas serve to be more universal, or in some cases available in both hard and flexible versions, shares Big Systems’ Peterman.
More manufacturers find that as a new material is introduced—or a material new to the segment, not so much new in creation—the ink must be revisited to perform more than adequately.
“Inks are adjusted to the substrates in order to give expected coloristic and application properties such as rub, wash, or light resistance,” continues Christophe Bulliard, marketing director, Sensient Imaging Technology.
Cipresso says ink sets are required to be more versatile today to meet the variety of substrates being used for end products. “Therefore, you must have an ink set that is fast drying, flexible, and as vibrant on plastic corrugated as it is on a folded carton.”
“Ink manufacturers adapt to end user requirements by creating inks suitable to the application, some customers need the ink to be more flexible while others have an adhesion protocol that requires a more rigid ink,” concurs Scott Einsig, director of business development, Engineered Printing Solutions (EPS).
Out in the Field or Under the Hood
Ink research and development (R&D) is driven by both application introductions and printhead improvements. Applications because they define what media is used and therefore the chemistry required to successfully adhere to the substrate while providing a high-quality appearance. Printheads because a machine can only run well when its parts and the fuel are suited for each other.
“I believe the application is the top of the pyramid in regards to ink development. As an OEM, we build machines around the application. The first step in that process is to determine which combination of printhead and available ink set will be compatible with the end user’s specifications. Printhead development is a long process and ink manufacturers can be more nimble when it comes to developing a series of ink suitable to the application, while considering the constraints of the chosen printhead technology,” admits EPS’ Einsig.
INX’s Reid says ink R&D is driven by applications, but both the ink and printhead act as enablers to achieve the application. “In some applications, specific printhead requirements may be simply mandatory, such as actual addressable resolution and firing frequency. In some cases, the type of chemistry may drive the use of one printhead over another based on chemistry limitations,” he argues.
Printheads pave the way for ink development, according to Peter Andrich, president, S-Qbism Corp. He explains that with printhead technology evolving significantly over the past several years one of the side effects is an increase in cost per printhead. “Therefore, more than ever, inks need to be formulated in such a way that not only the longevity of the printhead is preserved, but furthermore extended due to the higher replacement cost,” he recommends.
“Changes or advancements in printhead technology do influence ink R&D. Different types of printheads require different formulations and viscosity for optimal performance. You can have great ink, but if it doesn’t function well with the printhead it is intended for, it’s essentially useless for that application,” cautions Roland’s Hunter.
Eyal Duzy, marketing segment manager, HP Scitex, says that if there is a planned major change in printhead technology, a new ink is usually developed to support that. That was exactly what happened at HP when it introduced its High Dynamic Range (HDR) printheads, HDR inks were created in response.
Others believe it isn’t as clear cut as applications or printheads. “It is a mixture of usual drivers, namely cost, environmental and regulatory changes, and application driven requirements, such as faster output. Printheads, higher resolution, smaller drop sizes, and higher frequency droplet firing, all demand developments in ink technology,” lists Sun Chemical’s Saunders.
Whether driven by applications, printheads, customer demand, or something else entirely, the number of ink sets available to PSPs is staggering. Which to choose depends on whether the ink is right for the job at hand. With the diverse landscape afforded by digital printing, it is no surprise that most ink types are actively used. The possibilities of digital are endless and ink contributes to its potential.
Apr2016, Digital Output