By Elizabeth Quirk
Dye-sublimation (dye-sub) is the process of converting ink into a gas that fuses to textile fibers. There are two types of dye-sub printing—direct and transfer. Direct dye-sub printing involves sublimating ink directly to the fabric. It eliminates the need for transfer paper but requires pretreated fabrics. However, printed fabrics need to be run through a heat press or calendar for the sublimation process to bond the ink to the fabric.
In transfer dye-sub printing, the images or graphics are first printed to transfer paper. The paper is run through a heat press. When the transfer paper makes contact with the fabric in the heat press with temperatures between 385 and 400 degrees Fahrenheit, the paper releases the ink onto the fabric. The process allows for a wider range of fabrics to be used.
This article discusses both methods, with a focus on the latest demands.
Above: The Mimaki TX300P-1800 Mkll printer prints on natural fabrics, such as cotton, linen, and rayon, as well as any polyester.
When deciding whether direct or transfer dye-sub best suits your specific needs, it’s important to first determine what type of products will compose the majority of your output.
According to Randy Peters, president/CEO, The Mosaica Group, most customers do not understand that the fabrics for dye-sub transfer and direct printing are different. The weave and type of fabric may be the same, however, fabrics used with transfer paper do not need to be prepared for digital printing like fabrics used for direct dye-sub printing.
As such, there is a lot of environmental waste and cost associated with coating and preparing these types of textiles for the digital printing process. “Most fabrics need to be bleached, washed, and coated with an ink receptive coating before they can be printed on. In addition to the chemicals used to apply these treatments, there is a lot of water waste involved in the process of preparing these fabrics. Textile preparation is quite messy as these treatments are applied to the total fabric, not just a surface treatment,” continues Peters.
Mike Wozny, senior product manager, EFI, says dye-sub transfer typically provides an advantage for high-volume businesses that may have multiple dye-sub printers because users can offload rolls, move them to heat presses, and then free up those printers to continue printing. “The transfer workflow also makes it easier to change fabrics during a shift, as loading/unloading fabric is easier at the heat press than at a printer,” he explains.
Peters argues that the primary benefit to dye-sub transfer printing is quality. He believes the quality exceeds that of direct dye-sub due to the methodology of ink transferred to a substrate.
“Coatings on transfer papers are designed to keep the ink droplet on the surface of the paper, allowing for less ink to be used during the transfer process, thus saving customers money in the amount of ink needed to get their desired results. Overall, transfer printing produces better resolution, more vibrant colors, and crisper details. Additionally, the versatility of using a variety of substrates and applications is more appealing in the transfer method. Transfer printing enables printing on nearly every kind of surface or rigid product such as fabric, metal, aluminum, acrylic, glass, fiberglass, and plastic,” he adds.
Lily Hunter, product manager, textiles and consumable supplies, Roland DGA Corporation, argues that one of the biggest benefits of direct dye-sub printing is that there’s no paper waste, as you’re not printing onto transfer paper. “It’s a one-step printing method that’s ideal for fabrics and applications requiring heavier ink saturation and penetration.”
“However, keep in mind that while this method reduces costs because transfer paper is not needed, you need to buy coated fabrics that are more expensive than non-coated materials. Additionally, the final output may have less detail and image brilliance than output produced via dye-sub transfer printing,” she adds.
Many types of dye-sub customers express different needs and wants. For example, Ryosuke Nakayama, textile and apparel business solutions manager, and Victoria Harris, textile application specialist, Mimaki USA, Inc., say their customers are asking for more options or versatility in the amount of fabric types that can be printed with one machine.
Up until now, the biggest limitation with textile digital printing was the lack of a complete ink solution that worked equally well on every fabric type. In response, Mimaki recently introduced a textile pigment/sublimation transfer, direct sublimation/sublimation transfer, and textile pigment/direct sublimation printer, the TX300P-1800 MKII. The machine prints on natural fabrics, such as cotton, linen, and rayon, as well as any polyester. It offers great application versatility.
Durst Image Technology US, LLC also experiences this. According to Mike Syverson, textile manager, North America, Durst, printers that support direct or transfer dye-sub are more appealing to most print service providers (PSPs), so they have choice in print methods and can sell a wider array of goods.
Customers are also always looking for higher quality output. “Features like seven picoliter droplets, grayscale printing, light inks and gamut expansion, unattended operation, high productivity, and low operating costs are equally important. A system that requires very little user interaction—watching the printer constantly, repetitive purging, and adjusting media—is very valuable to PSPs as companies today are hyper-focused on reducing operating costs and reducing touches on the print jobs,” adds Syverson.
On the other hand, speed, increased productivity, and reduced cost are also primary concerns. While speed is prioritized, it shouldn’t reduce the quality of the final result when it comes to accurately capturing color and detail.
Other considerations when investing in a dye-sub printer include overhead expenses, ease of maintenance and operation, ink drying capabilities, carbon footprint, and space.
“Clients want to understand how frequent the ink sets need to be changed based on usage, and when it’s necessary to replace the printheads. Some sublimation printer manufacturers consider printheads to be a consumable, meaning upon purchase the printer may not even include the printheads and they may need to be replaced frequently, which can be quite expensive over time,” offers Peters.
Randy Anderson, product marketing manager, Mutoh America, Inc., explains that for rigid substrate customers, it almost always boils down to performance, with a smooth oftentimes glossy surface, every anomaly can be a potential problem and with metal substrates being the new art application, these customers want photo-like quality that requires small dot high-resolution capacity.
“Most of these are smaller businesses running much smaller volumes, who want the ease of use and quick maintenance, with Mutoh they are purchasing an industrial-built printer with that ease of use,” he adds.
In Hunter’s opinion, people want to get the most “bang for the buck,” so a printer that is versatile and can print both directly and indirectly with the same ink, like the Roland Texart RT-640M multi-function dye-sub printer, is advantageous. It allows for printing directly onto coated polyester fabric, as well as dye-sub transfer paper using the same Roland Texart SBL3 sublimation inks.
Five to Ten Years
Just in the past five years, new innovations in dye-sub technology make it an increasingly viable replacement for other forms of printing processes. Let’s take a closer look at what these professionals think about the future of dye-sub printers.
Many believe in continued improvement, offering faster speeds, more automation, and higher quality printing. This includes inline systems where the pre- and post-processing—in addition to print—are in one seamless, compact operation.
Marco Girola, marketing and communication manager, JK Group and MS Printing Solutions, states that the future of these printers will reach the highest level of automation and customization, overpassing distance limitation—ideally remote management, and highest energy and water saving.
“I believe inline sublimation will continue to be a popular and useful feature that will only become more prevalent over time. The ability to print transfer paper at the highest quality and the lowest cost will still be important, however. The biggest trends and advancements will apply to digital textile printing in general—including advancements coming to market in the industrial textile and apparel space that could make their way into graphics production,” states Wozny.
Hunter thinks ingenuity will come from the inks itself—new formulations that have improved lightfastness. “On the printer side, there will definitely be more smart technology features that can help troubleshoot and detect potential errors, making it even easier to use and maintain machines.”
Ink sets will also expand in regards to color choice—with some already doing so. For example, Epson’s SureColor F9470H dye-sub transfer printer features fluorescent pink and yellow ink. “The new SureColor F9470H introduces fluorescent ink support to further expand bold color applications, creating eye-catching output and providing greater versatility for customers,” Tim Check, senior product manager, professional imaging, Epson.
“I believe future systems will increase in speed and quality, similar to other aspects of the large format inkjet business. Further development in inks are likely a primary focus area for manufacturers. Features such as dry time and color gamut are always in development and have come a long way even in the past five years. Another area that continues to develop are the fabric and paper suppliers. There are constant improvements in fabric pretreatments in addition to the amazing variety of fabrics for virtually every application, from silicone edge graphics and trade show displays to home textiles, furnishings, and apparel,” says Syverson.
In Anderson’s opinion, printers should be recognized for what they truly are—printing robots. Using the Internet of Things, future printers will interface with laser cutters, robotic sewers, and production/costing software to produce products for customers waiting for clothing created specifically for them, while at the same time providing data to minimize cost and maximize output.
“I can envision a robotic arm with a printhead that prints on virtually any shaped surface by following the surface of that object with sensors to determine the distance between the object and printhead continuously,” he suggests.
When deciding whether direct or transfer dye-sub best suits your specific needs, it’s important to first determine what type of products compose the most of your output. The differences between direct and transfer dye-sub printing may seem small because they tend to yield the same result, but in reality they are very different. It’ll be interesting to see how these printers evolve and adapt to new and emerging technologies as well as customer demands.
Feb2020, Digital Output