Digital fabric printing continues to grow. From retail signs with a soft, tactile feel to canvas fine art reproductions, fashion samples, and one-of-a-kind home décor, textiles are now printed in any quantity with outstanding results.
To print with large format digital printers and inks, textiles require unique properties to maximize performance. With special coatings and pre-treatments digital print ink lies on the surface or penetrates properly. When the chosen textile proves to be compatible with the ink and printer, the output captures desired detail and color and avoids bleed.
Direct print, direct dye-sublimation (dye-sub), and transfer dye-sub are the print processes used for digital printing on textiles. Direct printing uses fabric in a similar manner as paper. When used with select types of fabric and/or with certain inks, such as eco-solvent or solvent, a special coating is necessary.
Transfer dye-sub prints graphics in reverse onto transfer paper and then a heat press sublimates the graphic onto the final textile. Direct dye-sub delivers similar results, but it eliminates the external heat press and transfer papers.
When working with polyester fabric, disperse inks are used. Nylon, silk, and wool use acid inks, and cottons utilize reactive inks. All of these textiles require a pre-coating to ensure proper results.
Pigment dyes are another ink option. These inks sit atop the surface of a textile and are cured. They do not require a special coating on the textile.
Solvent and eco-solvent inks penetrate the fabric’s coating, while UV-curable and latex inks sit on the coating surface. “We designed specific coatings to sit on the surface of the fabric. The ink, in turn sits on the surface of the coating that renders greater vibrancy of color and prevents bleeding of the inks,” points out James Gay, director of marketing, Fisher Textiles, Inc.
“Since this market is ever changing, we continue to develop fabrics and coatings regardless of the type of machine or ink used,” remarks Steve Weiss, director of sales, national accounts/print, Dazian LLC.
The process that Jacquard Products prefers is direct printing with disperse, transfer ink directly onto the fabric. “That is an improvement over the transfer method. Colors are subtle and not burnt or extracted looking. There is better penetration into the fabric, and you can use these same dyes on nylon. All of our polyesters accept transfer and direct print,” states Michael Katz, president, Jacquard.
Whether required or not, a coating makes for a quality print. “One of the things people don’t realize is that any fabric with a coating is going to print just a little bit better than an uncoated fabric. Because the fabric is coated it allows for the ink to stand up on the surface for a noticeably better print,” comments Jeff Sanders, digital sales, Pacific Coast Fabrics.
Developing textiles that perform for all printers, inks, and applications can be difficult. “A single product may work well for multiple outputs, however, we often tweak our ink receptive top coatings or treatments in order to maximize print quality,” shares Eric Tischer, director of textiles and specialty products, Verseidag Seemee US Inc.
Different coatings present multiple material characteristics. “PVC-, urethane-, and acrylic-based coatings each offer benefits. PVC coatings are an easy transition for print providers new to textiles, having traditionally printed on banner, SAV, and paper. Urethane, acrylic, and hybrid coatings are formulated to match the binders within different types of inks and are designed to strike a desired balance between image vibrancy, softness, and even wrinkle resistance,” explains Angela Mohni, VP marketing, Neschen Americas.
Understanding the limitations of one type of ink versus another is essential. “This is where experience and knowledge come into play to avoid expensive and time-consuming mistakes,” explains Blaise Humphries, product development, sales and marketing, inkjet media, DHJ International. The company’s Pearl product can be printed with solvent, eco-solvent, UV-curable, and latex inks on the coated side and by paper transfer dye-sub on the polyester side.
It is up to the printer model or ink to determine if a pre-treatment is needed. “UV-curable inks may not need a pre-treatment. We find, for example, the Durst Image Technology US LLC Rho UV printer works well with our fabrics without a pre-treatment while other UV printers do not. We have developed a pre-treatment for latex, solvent, and direct disperse sublimation printing,” states Michael Richardson, director of sales/marketing, print media, Aurora Specialty Textiles Group, Inc.
Aurora’s new SP pre-treated line of fabrics is compatible with latex and solvent inks. This process allows the fabric to remain soft and flexible, while controlling dot gain, line definition, and ink migration.
The coatings on Neschen’s SolvoTex, Pure Color, and DirectTex fabrics are not designed to hold water-based inks in place. However, the company offers a number of textile solutions for water-based, pigmented inks in its Printex and VariTex product families.
Que Media Inc.’s new SPFLG glossy polyester light fabric, SPFLS semi-glossy polyester light, SPFSG glossy super heavy, and SPFSS semi-glossy super heavy fabric launch in July 2011. The fabrics are designed to print with vivid photo quality and are coated for use on solvent, eco-solvent, and latex printers.
Digital printing on fabric is becoming easier as textile, ink, and printer manufacturers come together to co-develop and test products. Equipment and consumable vendors address compatibility challenges and set profiles for streamlined use. In the coming years, industry partnerships are expected to foster more technology advances.
Ink receptive top coatings will advance, especially improving the printability and hand of textiles all while reducing costing. “This allows for less ink and heat to be used and faster print speeds,” says Tischer.
A trend away from traditional PVC to PP, PP, and PET materials will develop, predicts Bryan Rose, VP and business manager, Cooley Commercial Graphics. “These materials not only require special formulations, but special surface treatments,” he says.
Korographics is adding recycled content products to its line. These include Horizons latex saturated recycled paper and Korographics RCV PVC-based recycled product.
Fray resistance may be the next big thing. “Adding fray resistance to fabrics saves print shops time and money in finishing,” explains E. Tyler Reich, director of marketing, Que Media.
There is continued movement away from solvent printers toward roll-to-roll UV-curable and latex systems. “Many of our current SolvoTex products already offer compatibility with these ink systems,” mentions Mohni. “New textile product development in three and five meter widths will certainly incorporate this industry trend.”
Richardson foresees printer speed increasing as direct printing to fabric rises in popularity. “It is important that pre-treatments keep up with the changing and evolving technology,” he notes.
A Perfect Fit
Digitally printed fabric is used in a variety of on demand, no-minimum applications from industries spanning fashion, décor, trade shows, and retail. The evolving market brings in new print customers and opportunities.
The production process is completed in either direct, or dye-sub direct or dye-sub transfer. A compatible fabric is chosen based on the process, printer, and ink used. Unique coatings and treatments allow for fabric choices to work well with varied print components.
The next article in this series looks at the collaborations between fabric, ink, and hardware manufacturers. Special partnerships, testing, and approvals between vendors presents high-quality products.