By Olivia Cahoon
Print service providers (PSPs) have many options when printing textiles with inkjet technology. They can print directly to a textile using UV or latex ink, or they can work with dye-sublimation (dye-sub). Dye-sub printing is categorized by two types—transfer and direct.
Direct dye-sub devices print ink directly on the fabric followed by the process of sublimating. Transfer printing involves printing to paper. The graphic is transferred from the paper to the fabric with a separate device such as a heat press or calendar.
Dye-sub transfer printing requires specific ink sets to ensure the color transfers well from paper to fabric. These inks should offer color vibrancy while providing print stability and fast drying capabilities for improved efficiency. To offer print service providers (PSPs) the best type of ink for transfer dye-sub printing, new sublimation ink sets are formulated for reduced water consumption and vivid output.
Above: Sawgrass developed the SubliJet-HD Flex high-viscosity sublimation ink set with an expanded color gamut including hard-to-achieve colors.
Textiles Seek Efficiency
When it comes to sublimation ink for transfer printing, PSPs request a variety of features including print stability, fast drying qualities, and color vibrancy. Together, these features allow PSPs to maximize productivity with shorter sublimation times.
Transfer sublimation inks designed for print stability offer consistent output, ideal for printed garments displayed in large volumes. Print stability varies based on the quality of the dyes and other components used in ink formulations, says Lily Hunter, product manager, textiles & consumables, Roland DGA Corporation. “This allows for lot-to-lot consistency in manufacturing, as well as quality control.”
David Lopez, textile solutions specialist, textile and apparel business development, Mimaki USA, Inc., considers print stability as one of the most important qualities of digital inkjet printer inks.
In addition to print stability, fast drying capabilities are important for sublimation inks because it speeds the workflow and helps maximize productivity, shares Hunter. Specific formulations allow ink to dry quickly and are typically vendor specific but also include simple formulations like less water for faster drying time. Without a fast drying capability, wet inks may transfer onto the back of the roll and require re-printing.
Inks with less water in the formulation usually have a higher dye content. This speeds up drying time, but also offers reduced water and ink consumption. Hunter offers, “that means a little bit of ink goes a long way when it comes to producing rich, vibrant sublimated output.”
Those in search of sublimation ink also look at color vibrancy. Tony Cox, business manager, Sun Chemical Corporation, explains that this includes inks with brighter and stronger colors, complemented by black inks with high-er density. A majority of ink demands are targeted toward shorter sublimation times to increase productivity and reduced weight transfer papers for significant cost savings, he adds.
According to Hunter, color vibrancy depends on the quality of the dyes used in the inks—the better the dye quality, the higher the vibrancy. She believes dye-sub is so popular because it produces eye-catching, appealing colors, which has a lot to do with dye and ink quality.
Batch-to-batch color consistency allows printed colors to maintain the same vibrancy over a period of time, shares Dan Barefoot, VP of global sales and marketing, Prism Inks, Inc. It’s also important that sublimation inks offer jetting reliability with little chance of printhead clogging. He explains, “the value proposition we most hear about has to do with providing product, which can be counted on to work day in and day out.”
Vendors Meet Demands
When seeking sublimation ink for transfer printing, PSPs look for a variety of attributes including print stability, color vibrancy, and reduced consumption. To meet these demands, ink vendors advance their ink sets with proprietary components.
Advanced Color Solutions (ACS) carries high-quality inks, consumables, and sublimation equipment. Its sublimation ink offering includes J-Next Subly ink, available in a variety of colors including fluorescent pink and yellow. “If you use the proper supplies and maintain your equipment, dye-sub is a sustainable business,” offers Nick Buettner, director of global technical sales, ACS.
Epson’s latest dye-sub ink technology, UltraChrome DS sublimation ink with high-density black, produces exceptional color saturation and high contrast. By offering improved black density with better tonal transitions and grayscale, Tim Check, senior product manager, professional imaging, Epson, says the SureColor F-Series dye-sub printers deliver high-quality results in the roll-to-roll fabrication product market. In addition, fast drying times and improved ink efficiency deliver low total cost of ownership for customized promotional production, soft signage, and cut-and-sew sports apparel, fashion, and home décor.
Mimaki’s dye-sub solutions include printers and ink designed to use less ink and achieve vibrant colors. “Because Mimaki engineers its own inks, we have total control over changing the ink for new technologies,” says Lopez. As the market continues to grow, he says Mimaki tries to stay ahead by creating new inks that have brighter colors and more stable printing qualities. Ink sets for transfer dye-sub include Sb54, in CMYK, light blue, light ma-genta, and fluorescent yellow and pink.
Prism Inks optimizes its ink particle size to enhance the vibrancy of inks while also balancing it to give higher lightfastness. Its color gamut is enhanced by neon and spot color offerings. “Our high-frequency jetting is based upon technology used in our other high-speed jetting products, which means consistent printing without printhead drop-out issues,” shares Barefoot. Additionally, its sublimation inks have an 18 month shelf life.
According to Hunter, Roland provides stable, high-quality sublimation inks at competitive prices to meet user demands. “We strive to develop and provide superior sublimation inks—like the Texart SBL3 formulations—that incorporate the qualities our customers are looking for and exceed their expectations when it comes to overall performance and output quality,” she offers. Roland’s Texart SBL3 sublimation inks are designed with less water in the formulation to reduce water consumption, produce vibrant output, and allow for faster drying time.
Sawgrass Inc. developed the SubliJet-HD FLEX high-viscosity sublimation ink set to provide the ability to achieve an expanded color gamut including hard-to-achieve colors. Within this formulation, the company also provides fluorescent capabilities. “With each new ink formulation and update to our printer software and solutions, we deliver more color options, greater print efficiency, and direct responses to market demands for sublimation printing,” explains Robin Kavanagh, PR manager, Sawgrass.
Sun Chemical recently launched its SunTex inkjet inks to meet key trends and challenges in the marketplace. Cox says this includes bright strong colors, dense blacks, strong resistance characteristics, and show through for double-sided textiles like flags. “As a leading supplier of pigments and colorants, we can access these materials to use with our inks in a way that is far ahead of our competition,” he adds.
While challenges are continually addressed by transfer dye-sub ink vendors, outdoor durability and proper maintenance remain concerns.
Sublimation inks typically last up to six months outdoors, presenting a challenge for PSPs with clients that demand high-level durability. At present, Hunter says improvements in durability are coming more from blank manufacturers rather than ink vendors. By using a blank with a special coating, PSPs can achieve printed output with up to three years of outdoor durability.
Ink challenges also result from how PSPs handle equipment throughout the entire printing process. Kavanagh believes this includes clean printer maintenance, calibrated heat presses, and transfer papers with consistent results. “If sublimation users don’t pay attention to the entire process, the quality of their output will suffer.” For example, while it may be tempting to lower costs by using cheaper transfer paper, Kavanagh cautions it may result in lower image quality with less-defined lines and borders or increased ink bleeding.
Maintenance and cleanliness problems often occur when the ink sits stagnant and the printer isn’t regularly used. “The longer the printer sits without use, the more a problem presents itself,” offers Buettner. This can be avoided by practicing proper use and manufacturer-specific maintenance instructions.
Challenges with sublimation inks are not only limited to output quality and maintenance. Market changes affect the price and availability of inks as well as transfer papers. Recently, market prices have dramatically decreased in addition to major companies stirring up the price competition, suggests Juan Kim, CEO, Valloy Incorporation.
Additionally, there is a rising concern for available sublimation ink sets for newer printheads. “Most inks are stabilized for Epson DX5/7 printheads, but there are high-frequency printheads coming like Epson 5113, Ricoh GH2220, and Xaar 1201,” offers Kim. “It’s important to develop stable ink to support those new printheads.”
Enter Pigment Inks
Advancements in pigment inks allow direct print technologies to serve as an alternative for dye-sub transfer printing. Pigment inks are expected to make inroads into the apparel and décor markets due to advancements in UV stability and general durability. “The ability for pigment textile ink to work with not only natural fabrics, but synthetics, gives pigment textile ink a strategic advantage,” explains Barefoot. “Color gamut and vibrancy gets better every year with pigment textile ink, and the fabric feel is almost as good as dye-sub.”
Pigment inks offer compatibility with a variety of fabric types, but when compared to polyester, sublimation inks tend to hold greater value. Sublimation inks penetrate and dye the actual fabric fibers of polyester material for a soft feel. Unlike dye-sub, pigment inks sit on top of the fabric fibers. By penetrating the fibers, sublimation ink allows for sublimated products to maintain a high-rub resistance without rubbing off or onto other projects, says Hunter. This also holds true for sublimated rigid substrates where the ink dyes the polyester coating. “Dye-sub transfer printing onto polyester still yields output that’s extremely vibrant,” she adds.
Check finds that sublimation ink’s ability to penetrate fibers gives it the advantage of having greater color vibrancy with sharper detail. “It can also be used with raw/uncoated polyester fabrics, resulting in no change to the hand of the fabric.”
Because it penetrates fibers, Lopez believes the longevity of dye-sub surpasses textile pigment when items are washed or worn. Additionally, dye-sub isn’t limited to fabric. “There is an emerging market with photographic dye-sub to metals and woods that feature a polyester-based coating on them, which cannot be done with textile pigments. The versatility of dye-sub will always be greater than textile pigments,” he suggests.
While Barefoot believes pigment inks are advancing, he says there will always be a need for sublimation inks, especially for hard goods. “Pigment textile ink does not work well with ceramics, metals, or non-fabric products.”
Despite advancements, Cox doesn’t see pigment inks for direct print technologies immediately affecting the industry. Broadly speaking, he says sublimation inks are formulated to print on polyester and polyester-rich fabrics, while reactive inks are ideal for natural fibers. “As a general rule, reactive dye and pigmented inks are suitable for a wider range of fabrics, but there is still a place for sublimation inks for transfer printing.”
Performance capabilities aside, transfer inks typically yield greater inventory and stock redundancy advantages including an overall lower production cost. According to Cox, the financial risk of holding stock of unprinted transfer paper is lower than holding stock of finished garments, and the disposal cost of unwanted or unsold stock is significantly lower.
PSPs select transfer dye-sub technology for eye-catching images with a durable, soft feel. To keep up with demand, advancements in transfer ink sets and devices are designed to expand compatible materials and available colors.
New self-weeding technologies allow rich sublimation colors to be transferred to natural fibers like cotton. “It’s becoming an attractive alternative to direct to garment pigment inks,” says Kavanagh.
Self-weeding transfer paper allows images to be transferred without leaving a window or shadow on the garment. According to Kavanagh, weeding can be accomplished using different methods, generally with multi-step processes.
Advancements also expand UV resistance and weatherability for transfer sublimation inks. For example, Barefoot shares that Prism Inks’ polymer scientists are developing new UV inhibitor technology to increase outdoor durability. In addition, the company is developing new polymer technology that allows customers to use less expensive paper.
According to Hunter, one of the biggest transfer sublimation ink trends is the introduction and popularity of specialty colors like fluorescent. “These inks can be combined with process colors to create a multitude of eye-catching fluorescent inks.”
Sublimation transfer technology is versatile and spans a range of applications including awards, promotional products, garments, and home décor. While pigment inks are advancing into apparel and décor markets, sublimation inks remain a cost-effective solution for printing to polyester-based surfaces.
Aug2018, Digital Output