By Amber E. Watson
The list of uses for digitally printed fabric continues to grow, and media suppliers are challenged to keep pace with heightened demand.
Digital fabrics are processed differently from traditional print products, from the initial weaving processes to the coatings they receive. There are also different criteria to meet, such as achieving a brighter white point, ensuring there are no imperfections that could cause issues during the printing process, applying the most suitable coating for the end use, and maintaining consistency throughout.
In the future, print service providers (PSPs) can expect better results from digital textiles, such as improved vibrancy, quality, and durability, along with easier profiling, and more customized products for all different types of applications—both indoors and out.
Many major manufacturers of digitally printable fabric are privately held and conduct a significant share of business, though their names are kept behind the scenes. It is a market that continues to grow rapidly.
Tim Greene, director, wide format printing consulting service, InfoTrends, points out that while there are digitally printable textile manufacturers that print shops know, there is a whole other set of fabric manufacturers.
“These companies are very much suppliers of raw materials, so their fabrics have not been necessarily developed specifically for digital printing, but they are run through digital printers nonetheless,” he continues.
Fabric Inside and Out
Different textile materials, including satin, cotton, silk, rayon, bamboo, nylon, canvas, and polyester are manufactured specifically for digital print technologies—both sublimation and direct.
Digital fabrics are not only for all varieties of clothing and accessories, but also, as Michael Katz, president, Jacquard Inkjet Fabric Systems, points out, are used for “home furnishings, such as lampshades, pillows, furniture, and leather goods, as well as for prototyping and production, such as showroom layouts, point of purchase (POP) and advertising displays, crafting/quilts, advertisements like banners, original art exhibitions, and wall art like photos, fine art, or themed décor in hotels.”
Other uses include “flooring and mats, frontlit, gaming tables, geometric/stretch displays, glass and screen wipes, opaque/blockout liner, photographic back drops, projection screens, roll up banner stands, silicone edge graphics, table covers, tension fabrics, and wallcoverings,” adds Sharon Roland, advertising manager, Fisher Textiles.
“For textiles, dye-sublimation (dye-sub) is primarily used on polyester fabrics. UV durability of the ink limits the use of this form to indoor or short-term outdoor applications,” notes Mike Von Wachenfeldt, technical services manager, custom fabrics, Glen Raven, Inc. However, there are more durable fabrics and inks that are suitable for outdoor applications.
Sattler AG, for instance, focuses on digital printable truck tarpaulins for which “a special surface sealing combines soil repellency and digital printability,” explains Michael Pichler, product management PRO-TEX, Sattler. “Flatness, consistent high-quality level, perfect printability, perfect processability, and weldability are parameters appreciated for this specific application.”
From the Yarn Up
One main difference between digital versus traditional textiles is not so much in the fabric itself, but in the printing process. “Digital printing is faster and less expensive than traditional production of printed textiles, but only up to a point,” explains Katz. “Eventually, there is a tipping point where the cost and production speed of traditional production methods wins out over digital—where that point is, varies with the job.” He explains that longer production runs of the very same product favor traditional production.
Digital fabric has its own characteristics and requirements. “It is essential that any digital fabric is meticulously scoured and bleached so that ink is accepted uniformly from edge to edge,” shares Jeff Sanders, digital fabrics sales manager, Pacific Coast Fabrics (PCF). “With traditional rotary screenprinting, ink is driven deep into the fabric by mechanical means, whereas it always remains on the surface with digital printing. Due to surface printing, the fabric face must remain free of any imperfections that are magnified once ink is applied.” It is equally important that digital fabric is prepared free of weaving defects, broken filaments, or other surface imperfections that may cause printhead strikes.
Sanders believes that a quality digital fabric is designed “from the yarn up.” This means starting with premium yarns that are optimized for printability and maintaining the consistency of product from production lot to production lot. “The frustration, time loss, and associated costs needed to continually re-profile due to changes in a fabric’s construction can be avoided with good quality control on the front end of development,” he advocates.
Tyler Reich, director of product development, Qué Media, Inc., also hones in on the importance of the weaving process when it comes to digital dye-sub and direct printing. “Traditional fabrics were woven as quickly as possible—it did not matter if minor flaws were found in the material because they were covered easily during the dye process,” he explains.
“Digital products, on the other hand, are pure white and coated for high-definition ink reception. Flaws are easily detectable,” continues Reich. While many coaters wash or bleach their base before coating to get out most of the impurities or dirt particles, he cautions that this may cause the fibers to become more brittle, which could affect the longevity of the fabric. High-end weaving machines help manage this issue by weaving clean fabric from the original fibers.
Qué Media uses a wet weave process on its fabrics; the use of reverse osmosis filtration systems allows control of the textile production from start to finish.
Eric Tischer, president, Verseidag seemee US, Inc., explains that Verseidag is a vertically integrated manufacturer. “We build our fabrics from yarn to end product to continually innovate on multiple levels, including yarn and ink receptive top coating or treatment advancements.”
The various coatings applied are another crucial component of a fabric. “The difference in manufacturing to yield variances in ink compatibility is all based in the proprietary coating and finishing processes,” explains Michael Compton, business development manager, Top Value Fabrics. “Depending on how a fabric is coated or finished, it might be compatible with direct dye-sub, dye-sub transfer, UV, solvent, screenprint, or latex inks.”
Since fabrics for direct print are specifically designed with coatings that work in conjunction with the specific inks that the printer uses, it takes a lot of time, research, and testing. “In dye sub-transfer, Dazian creates a fabric that has a specific look, shimmer, shine, opacity, or a unique effect, glow, or diffusion so that the customer gets the look they desire,” states Steven Weiss, director of sales, national accounts/print, Dazian, LLC.
Sanders cautions that, “all coatings are not created equal; nor are the methods used to apply these coatings. Coatings can be padded, dipped, blade coated, or fully immersed onto a product. Knowing how to best utilize all of these methods is key to printing success. For instance, a light box fabric needs to be coated on one side only, so for this, PCF employs a blade method, while a sports garment fabric coating is always applied with full emersion.”
“After the fabric comes out of the mill, it can go directly to the outfit that coats, and sometimes paperbacks, the material for the digital printer. The digital fabric supplier coats the fabric depending on its composition and ink type,” explains Katz.
Von Wachenfeldt adds that, “many textile products receive an inkjet receptive topcoat or prepared-for-print finish that allows them to receive solvent, eco-solvent, UV-curable, and latex inks.”
Another challenge involves the post processing that is required with acid and reactive dyes. “Disperse and permanent textile pigment ink sets do not require challenging post processing, whereas printed fabric with acid and reactive dyes need to be washed after printing,” shares Katz.
Consistency is Key
One basic but crucial component in developing any new fabric is an understanding of the end use of the application, and the conditions to which it will be subjected. For instance, whenever PCF sets out to develop a new flag or banner textile, it rules out most woven fabrics, opting instead for a warp knit. “Warp knits are inherently stronger; when frayed they do not unravel the way that a woven does,” explains Sanders.
Likewise, when creating a fabric for the sports apparel market, PCF makes sure that the moisture management coatings are of a superior quality that lasts the life of the garment and does not wash out after three or four uses. “Also, frame system fabrics must have just the right amount of stretch so that installation is easy, but not so much stretch as to cause sagging over time,” adds Sanders.
Dazian takes into account the product’s end use, accessing the type of print method and ink used. “This is a difficult process,” admits Weiss. Dazian overcomes this hurdle by talking directly with customers and maintaining a good relationship with printer manufacturers and ink suppliers that welcome their input.
Roland agrees that some of the biggest obstacles in developing fabrics are the compatibility of inks and coatings for direct printing. “It’s a trial and error process—some fabrics work great and others take several trials before a product passes our standards and can be commercialized.”
“The biggest issue textile manufacturers face with the development and market usage of printable fabrics is the vast number of print outputs and inks in the marketplace. There is always a thin line between optimizing coatings to work with multiple outputs without losing print quality,” continues Tischer.
Consistency is a main concern. For example, Compton shares, “it is important to keep a highly consistent white point so that customers don’t have to change profiles. Any printer will tell you just how important color is to their customers, therefore, it is important to all of us. When one of our printers is working with a trademark Pantone color, they enjoy having a consistent white point so it is less work in changing profiles to achieve the color their customers expect.”
Surface properties are of utmost importance in digital print. “Customers must be able to rely on the fact that there is no inhomogeneity on the printing medium, as a perfect printing result is not possible without this regularity,” says Pichler.
The Next Generation
Fabric manufacturers constantly strive to compete. Along with faster printers, dyes that do not require fixation, and easier profiling systems that allow for different fabrics to be switched out quicker, the quality and vibrancy of digitally printed textiles also continues to improve. There are more coating options, substrate options, and treatments to enhance color.
“There is added development of products specifically engineered for certain applications, such as double-sided print, backlighting, and emerging applications such as flooring,” adds Jeff Cheatham, director of sales, Fisher Textiles.
Going forward, PSPs can expect to see more emphasis on the availability of flame resistant fabrics, which are especially important to retail, museums, hospitals, schools, and trade show environments. “It is critical for customers to have a high fire-rated product that is approved by any fire marshal countywide,” explains Weiss.
The number of different textiles available to digital printers is expanding every day; there is added pressure for media manufactures to continue to customize products for various uses in digital print.
“The expected quality levels of digital products far exceed traditional textiles,” notes Cheatham. There are many elements to perfect when it comes to digital textiles, but it’s a space that is being worked and improved upon every day.
Jul2014, Digital Output