In science, sublimation is defined as the transition from a solid phase to a gas phase without passing through an intermediate liquid phase. For example, dry ice (frozen carbon dioxide) becomes a vapor when exposed to temperatures above -109 degrees.
In digital printing, sublimation occurs when the dyes in a specially formulated ink are heated and pressed to a sublimation transfer paper, polyester fabric, or poly-coated object or panel. When the temperature reaches a point between 350-400ºF the solid dyes transition into a heated gas that opens and permeates the fibers of polyester fabrics or the polyester or polymer coated materials.
When the fabric or solid object cools and dries, the dyes revert back into solid form. The print feels like the original substrate and resists water damage, scratching, peeling, cracking, and fading.
Two types of sublimation processes are used in the printing industry; sublimation transfer and direct sublimation.
In this process, the inks are printed in a mirror- or reverse-print mode on specially treated sheets or rolls of sublimation transfer papers.
Then the printed paper is loaded onto a heat press along with the fabric or item to be decorated. The ink transfers to the substrate when the heat press applies a controlled amount of heat and pressure for a prescribed period of time. The settings for heat, pressure, and heat-press time are determined by the characteristics of the textile or item being decorated.
Heat presses are available in a variety of sizes and configurations to accommodate the many different sizes of items that can be decorated with the sublimation process.
Heat presses with flat surfaces and specialized accessories are built for items such as rigid panels, T-shirts, and all types of garments. Specialized heat presses are available for decorating caps, mugs, drinkware, and other cylindrical objects.
Protective papers are available to prevent stray droplets of heated ink from reaching the surface of the heat press or the wrong side of a decorated T-shirt.
When an item is removed from a flat heat press, the operator must remove the transfer paper as the object cools.
Rotary heat presses called “calendars” are used to transfer inks from rolls of printed paper to rolls of polyester fabrics. Some calendars can also handle a single piece of textile at a time.
The direct printing and fixation process for imaging on polyester fabrics eliminates the time and expense of buying, storing, and removing different weights of transfer papers for different types of fabrics.
In the direct process, disperse dye inks are printed directly onto polyester fabric. The printed fabric is heated and pressed to “fix” the inks onto the polyester fibers.
The disperse-dye inks penetrate further into the fabric than inks applied to the fabric via transfer papers.
Direct printing tends to produce less vibrant colors with fewer fine details than sublimation transfer printing. But direct-printed fabrics are more durable, making them suitable for many decor fabrics and carpets.
This ink “fixation” step can either be performed on the same calendar used for the dye-sublimation transfer process. Or, the ink and polyester fabric can be heated in an inline fixation unit attached to the printer.
“Hybrid” soft-signage printers are built to handle either the sublimation transfer or the direct printing process.
Some hybrid models include an inline heating unit so the press operator doesn’t have to reload the printed rolls of polyester fabric onto a separate calendar. This can be a major time- and space-saver when creating sublimation prints on fabric rolls that are more than 10 ft. wide.
The direct printing process enables large-format graphics businesses to efficiently produce long runs of fabrics up to 196-in. wide to make seamless banners and backdrops for trade-show exhibits, museums, theater stage sets,and event venues.
The direct printing process produces the greater durability needed for applications such as upholstery and carpets
The best known manufacturer of calendars for dye sublimation and fixation calendars for both soft signage and cut-and-sew apparel is Klieverik, which makes units that can apply heat and pressure to the fabric and transfer paper rolls printed on the 3.2 and 5-meter dye-sublimation and hybrid soft signage printers.
White or light-colored polyester fabrics work best for sublimation, because sublimation ink sets don’t include a white ink that can produce a base layer for bright colors. Poly-cotton fabrics and ready-made garments can be sublimated as long as the fabric has a high level of polyester.
A single type of polyester fabric won’t be suitable for every application.
Companies such as TVF and Fisher Textiles manufacture sublimation-ready fabrics for specific applications such as backlit graphics, front-lit graphics, athletic wear, jerseys, fashion apparel, home furnishings, upholstery, and casino gaming tables.
Each fabric is manufactured to provide the weave, stretchability, and specialized coatings that an application might require. For example, fabrics created for backlit graphics should have a tight weave so pinholes of light don’t appear.
Fabric graphics that will be frontlit should have a backing or a liner for opacity. Fabrics printed for trade-show displays are coated to meet fire-retardancy standards.
Ancillary finishing equipment is needed to convert sublimated fabrics into sellable products. For example, a laser cutter may be needed to produce soft signage that doesn’t fray along the edges.
Industrial sewing equipment may be needed to add silicon-edging for insertion in different sizes and types of aluminum framing systems built to keep the printed fabrics free of wrinkles and distortion for maximum visual impact.
If you want to convert the digitally printed fabrics into garments, a contour laser cutter and industrial sewing equipment will be needed. The printed fabric must be precisely cut into the pieces that will be sewn to make apparel, drapes, blinds, and upholstery.
The range of rigid panels that can be sublimated is expanding because printed panels are being used for more than decorative art. Architects and interior designers are incorporating decorated building materials into their original designs for new or remodeled spaces.
Duraluxe makes powder-coated sublimation-ready panels that can withstand years of extreme display conditions. Their most durable panels can be used for building facades, shower walls, backsplashes, tabletop, ceilings and outdoor signs. And like Chromaluxe, they offer sublimatable metal panels for art and photo displays and photo gifts.
Wholesale suppliers such as Conde and Best Sub sell a wide range of promotional products and gift items that can be sublimated, including flip-flops, neckties, ceramic ornaments, plates, acrylic photo frames, pet supplies, and stainless-steel water bottles.
The supplier of each rigid substrate or promotional product will provide instructions for the best combination of heat, pressure, and time to achieve the best ink transfer. They also offer instructional videos that demonstrate techniques for getting the best results.
Because so many variables exist in achieving sellable-quality products, it’s important to track the actual costs of your prepress, inks, substrates, labor, and waste.
At first, your waste costs may be high, as your staff learns how to dial in the settings that achieve the best results on the specific products you sublimate in your shop.
Some print-service providers decide to focus on fulfilling a few niche products so they dial in a sublimation workflow that consistently produces the color predictability and quality the client expects.
Whatever workflow you develop to create sublimated products or textiles, Ordant software can help you set up an automated system for efficiently creating estimates, managing orders and inventories, and shipping and invoicing finished products.
Your sublimation printing workflow can be set up to produce line items for multi-piece orders that include items printed on other devices such as digital and offset presses.
Our integrated web-to-print storefronts make it easy to set up online systems through which incoming, pre-approved sublimation jobs will be automatically directed to the right device to start the process. To schedule a demonstration, visit ordant.com .