by Cassandra Balentine
Dye-sublimation (dye-sub)—transfer and direct—represents a popular method for textile printing. Ease of use and low capital cost are two primary reasons this process is appealing. Inks continue to evolve to improve quality and durability.
Transfer dye-sub involves printing to a transfer paper using dye-sub ink. Heat and pressure are then applied to convert to a gas that bonds to the fibers of a selected substrate. With direct dye-sub, ink is jetted right to the substrate and heated. Both methods are popular for textile printing.
“Sublimation printing is one of the most common technologies used for digitally printing textiles, representing well over 50 percent of the output production. It is popular in the wide format space, but is also growing in the industrial space as installations of industrial production printers have increased,” comments Simon Daplyn, product and marketing manager, Sun Chemical.
In recent years, Lily Hunter, product manager, Professional Imaging, Epson America, notes a shift in the textile industry from global to regional suppliers in response to ongoing shipping and supply constraints. “This has continued the adoption of dye-sub, underscoring its benefits for regional suppliers. Moreover, print service providers (PSPs) just getting acquainted with the technology are now understanding its full potential and recognizing its expanded capabilities.”
Above: INX’s DT9 and DTX inks are developed for the i3200 and i1600 Epson series of printheads. DT9 is suitable for direct printing and transfer, making it ideal for soft signage.
Rise or Decline
As the textile print industry evolves so does dye-sub.
Josh Hope, director, marketing, Mimaki USA, Inc., believes transfer dye-sub is here to stay. “The application opportunities are vast, from traditional garments, interior décor, and soft signage to hard surface transfer such as aluminum panels for artwork or tabletops for furniture decoration.”
“We expect sublimation printing to maintain and potentially grow its market share,” says Daplyn. “There has been some recent market upturn due to increased demand in the sign and display as well as sports apparel markets, and this trend is expected to continue. Sublimation is well positioned to support printing of recycled polyester, which is used increasingly in these industries. While the largest area of growth is in Asia, markets in North and South America show consistent growth.”
Anne de Brouwer – Veldman, product manager, SPGPrints, points out that for a long time, direct disperse printing was the most widely used textile printing technique for printing polyester fabrics, especially for sportswear, because disperse is known for its washing fastness. “Sportswear is washed often. In other polyester markets, digital sublimation printing quickly became more popular because the process is simpler, and this technology is known to be much more sustainable because no steaming and washing is required,” continues de Brouwer – Veldman.
“While the data is not suggesting a decline in the use of dye-sub—quite the opposite, actually—I am noticing a shift in scale for the equipment and resources used to produce graphics,” admits Michael Litardo, marketing manager, Mutoh America, Inc. “In a post-COVID society, the desires for micro-scale/desktop or very large 3.2-meter-plus solutions are starting to become paramount. That said, there is still an important market segment for 44- to 75-inch printers in sports apparel, intermediate cut and sew, and print-on-demand personalization.”
Paul Edwards, VP, digital division, INX International Ink Co., sees the possibility of a gradual change in popularity for dye-sub textile printing. “The dye-sub process is somewhat ‘greener,’ meaning the amount of contaminated wastewater produced when printing with dye-sub is far less than conventional reactive dye printing. The printing process is also less complicated and suitable for local manufacture or the onshoring of products.”
Hunter expects the popularity of dye-sub to continue to grow as it’s such a versatile solution that it permeates many market segments, including apparel, home décor, wall applications, and signage applications. “There are few other wide format printing technologies that can rival the versatility of dye-sub and its ability to diversify product offerings.”
Furthermore, Hunter says select dye-sub solutions offer an expanded color gamut to enable the reproduction of challenging colors like fluorescents, creating stunning gradients and accurately matching brand colors, which significantly enhances their value proposition.
Dye-Sub Benefits
Several benefits are associated with dye-sub, including versatility, quality, and sustainability.
Hope points out that sublimation transfer is a near-waterless process. “The conventional textile dying method generates on average 14.5 liters of wastewater per square meter of fabric processed, based on our company’s research. The wastewater contains chemical substances used in pre- and post-processing and is considered an environmental concern.”
In contrast, a fully digital textile process consisting of a sublimation transfer printer and dye-sub inks, transfer paper, and a transfer heat press can produce large quantities of printed textiles ready for finishing without using any water and with no risk of chemical contamination, shares Hope.
He points out that Mimaki offers this scenario as a complete package—TRAPIS—a digital process that generates almost no wastewater, just the amount in the waste ink generated by the printer’s automatic maintenance function. This even includes wastewater generated in the transfer paper manufacturing process, with wastewater cut by approximately 90 percent compared to conventional digital dyeing systems.
Marco Zanella, global business development director – inkjet, INX Europe, points out that pigments have a similar profile to sublimation in terms of sustainability. “This is due to formulations being printable without pretreatments, and with minimal impact on the process. It also results in extremely low water waste impact, with only a limited amount needed for cleaning the belt in some cases.”
When formulated correctly, sublimation inks can be used in a hybrid set up for printing, either through transfer paper or directly to the fabric. “Direct printing enables better penetration of the ink while removing an extraneous process input to the paper, though it does require chemical precision,” explains Daplyn.
Because sublimation is a dry process, it enables a simplified workflow and set up with a smaller footprint, allowing for easier adoption. “It is a fast process, which permits users to begin their print very quickly and give less attention to pre- and post-treatments that are often necessary with other technologies,” says Daplyn.
“Sublimation printing can achieve striking, vibrant results with excellent image sharpness. Though mainly used with textiles, it can also be used to decorate a range of other surfaces,” adds Daplyn.
Unlike traditional textile dying techniques, Hunter feels that digital printing offers unparalleled design flexibility, boasting an expansive color gamut and color accuracy. “Due to cutting-edge technology, such as the PrecisionCore printhead and Nozzle Verification Technology in the Epson SureColor F-Series, precise details can be reproduced with clarity and at photographic print quality. This offers the ability for textile designers to create intricate designs featuring fine lines and details, color gradations, and vibrant colors.”
There is also the benefit of expanded color gamut in certain situations. “There are dye-sub printers that offer expanded ink sets, with colors outside of the traditional CMYK offerings. These offerings empower designers and PSPs to produce vibrant textiles to match apparel trends, safety apparel requirements, sports jerseys, soft signage, and décor that often include specific colors,” says Hunter.
There is a distinct permanence in using dye-sub that you do not get with other technologies. “Repeated washability and outdoor durability are unmatched and allow for higher consumer satisfaction,” comments Litardo.
Personalization is another perk. “Dye-sub is an ideal method for fulfilling medium to large runs of personalized apparel, making it perfect for supporting local sports clubs, teams, schools, and similar groups. Additionally, it offers a seamless way to produce one-off personalized gifts. This versatility allows businesses to extend their services beyond large batch orders, tapping into the demand for small, unique gifts,” adds Hunter.
Associated Challenges
The biggest challenge of transfer dye-sub is fabric compatibility.
Litardo points out that dye-sub is a premier method of transferring graphics to polyester-based textiles. “The biggest non-starter for dye-sub is the limitation to polyester-based materials. This doesn’t necessarily reduce the overall variety of different products that can be produced, but dampers PSPs from creating things on natural fibers such as cotton or on raw materials like uncoated metal,” says Litardo.
“Dye-sub only works well with polyester fabrics or with fabrics containing a significant amount of polyester,” notes Edwards. “That said, due to its bright and strong color gamut, it can be a great choice for sportswear applications and apparel.”
Hunter stresses that PSPs need to understand the fabric limitations for textile applications. Dye-sub is best suited for polyester fabrics, and those fabrics offer advantages including durability, rub resistance, and versatility.
Sublimation transfer printing adds multiple variables to the print production workflow, including transfer paper, fabric, and the transfer process itself. “Because of this, it is easy to get bogged down in all the possible combinations. It is advisable to simplify the paper and fabric combinations and test to ensure all aspects are working together well,” shares Hope.
Daplyn notes that many inks are not versatile enough to be used with different papers, so they must be selected for their designated use. “When switching from a low weight, uncoated paper used for fashion to a higher weight, tack-coated paper for sports apparel, the ink needs to be changed to maintain the same print quality and color uniformity.”
Edwards admits that there are some challenges as it relates to the transfer process. “Take care to ensure all the process variables such as heat, substrate type, and transfer media are under control and consistent. One dye-sub drawback as a technology is it has a lower lightfastness than pigment or reactive dye.”
“The interaction between transfer paper and sublimation ink is sensitive. There are plenty of papers available. For economical reasons, printers would like to use lightweight papers. Some regions prefer even uncoated papers, or direct printing. Then also fastness is a crucial factor,” says de Brouwer – Veldman.
Another challenge is avoiding waste. “Transfer paper may easily become a waste product, although in many cases the paper is able to be recycled. Another common area of waste is ink. Some of the ink and dye often remains on the paper without being transferred to the fabric during printing. To avoid ink and dye waste, it is important to select the inks with the best transfer rate,” advises Daplyn.
Dye-Sub Solutions
Dye-sub printing is well suited for a variety of textile applications. For print providers, soft signage is an easy add on. However, some of the latest technologies make the appeal for apparel applications. Dye-sub inks continue to evolve to support quality output.
Aug2024, Digital Output
