There are three primary technologies that allow print service providers (PSPs) to create digitally printed textiles—transfer dye-sublimation (dye-sub), direct dye-sub, and digital direct to print. All are relevant to today’s growing textile market. Although, each works best with certain types of material for various reasons, including—dot gain, coating issues, and ink compatibility.
In this exclusive online series we highlight the three technologies and provide an overview of available fabric products. Look for a comprehensive, three-part series on textiles in the July, August, and September print issues of Digital Output.
Step-by-Step Polyester Printing
Dye-sub transfer printers print graphics in reverse on transfer or carrier paper, which are then transferred to polyester fabric using a roll-to-roll heat press. Heating creates a chemical reaction that bonds the ink to the fabric. "This type of technology is primarily used for polyester signage applications," says Patti Williams, consulting partner, I.T. Strategies.
The transfer process requires sublimation transfer paper. SpectraJet is one supplier whose transfer papers are fully manufactured in the U.S. SpectraJet’s five-meter SilverBack transfer operates efficiently with solvent-, oil-, and water-based dye-sub dyes. This product eliminates large transfer paper inventories by reducing the various papers required for each dye. It is available in widths up to 198 inches.
Waste is a concern for print shops, especially as they strive to be more environmentally conscious. "We are as ‘green’ as they come," says Guy Spinelli, president, SpectraJet. SpectraJet’s sublimation transfer paper, among others, is recyclable after transfer to fabric.
Hewlett-Packard (HP) offers the HP Scitex XL1500 dye-sub upgrade kit, which allows PSPs to easily enter the textile printing market with minimal capital investment. "The upgrade kit delivers high-quality, textile signs that can be washed or dry cleaned without affecting quality," says Grad Rosenbaum, VP, North American Signage Business, HP.
When the HP Scitex XL1500 upgrade kit is used, solvent sublimation ink is printed onto a sublimation transfer sheet and then the sheet runs a heat transfer at 402 degrees Fahrenheit for 30 to 40 seconds, putting it in direct contact with the desired textile. "During this time, the ink turns into a gas, and the gas is pushed outward to the textile substrate and creates a chemical bond," says Rosenbaum. This process is similar to most dye-sub transfer printers. After the print is completed, the textile is separated from the transfer paper using a different press.
"Dye-sub transfer printing yields the highest quality image and best color on polyester substrates, but requires the expense of transfer paper, as well as an investment in a transfer press," admits Andrew Oransky, director of product management, Roland DGA Corporation. Roland’s Hi-Fi Express FP-740 is a 74-inch printer equipped with eight piezoelectric printheads. Each set of two printheads is designed to work in unison, speeding up the print process. HeatWave SBL2 ink is specially formulated to eliminate clogging, print defects, and color issues often associated with third party ink.
Although dye-sub transfer traditionally works best with polyester fabrics due to ink limitations, manufacturers are working to expand the market. The ColorTextiler 64DS from Seiko I Infotech is a dye-sub printer using oil-based ink. The printer is specifically for entry-level digital service bureaus. It prints on media up to 64 inches wide at 720x540 dpi. According to Seiko, the ColorTextiler’s ink provides longer lightfastness on polyester fabric compared to typical water-based dye-sub ink.
EFI VUTEk offers oil- or solvent-based devices for printing onto transfer paper or directly onto textiles. The VUTEk FabriVu superwide printer is an oil-based dye-sub solution. Another alternative is the VUTEk 3360 with the Fusion option, which creates a solvent dye-sub solution.
The printer uses UltraTex solvent dye-sub ink in addition to standard solvent ink. "The Fusion option enables customers to easily switch between traditional solvent and dye-sub solvent inks in a single printer without much waste," says Chuck Dourlet, VP of marketing, EFI VUTEk. Changeover from the traditional solvent to the dye-sub takes about 15 minutes. "More customers are migrating to the Fusion option because the output on the solvent-based dye-sub is fantastic, and it gives the user two printers in one," he adds.
Next week learn about direct dye-sub, specifically in comparison to transfer. Also, we talk with print manufacturers offering this type of device.