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Digital Technologies and the Apparel Decorator, Part II
By Johnny Shell, Vice President - Technical Services, SGIA
In Part II of this series, we will look at laser transfers, dye sublimation, heat-applied vinyl, and print-and-cut media. Part III will dive into heat-set media and direct-to-garment inkjet as ways to empower your shop.
To produce laser transfers, one must incorporate either a laser printer or copier using standard toner and special laser transfer paper. The technology, properly termed electrophotography, uses static electricity to generate a printed image. In essence, these devices effectively write the image to a photoconductive drum by neutralizing the static charge in certain areas. The charged areas of the drum attract the dry toner, which is then fused to the paper as it passes through a pair of heated rollers, essentially melting the toner powder and bonding it to the transfer paper, which is coated with special polymers designed for dry toner applications.
Using a heat press, the printed transfer is pressed to the garment at 190°C-204°C (375°F-400°F) for 10 to 30 seconds. The heat causes the coating to split from the paper, trapping the toner between it and the garment's fibers. As with inkjet transfers, using poor quality laser transfer paper will cause images to deteriorate after only a few laundry cycles. Here, too, the type and number of coatings as well as the base sheet material will dictate image quality and durability. For optimum results, use only premium papers.
Laser devices come in many flavors, but industrial models are almost infinitely adjustable in both speed and heat settings so that the device is easily dialed to meet the requirements of the paper being used. Economical laser devices less than $300 will experience problems because of the internal heat settings, which for the most part, are too high for laser transfer paper.
Desktop laser devices are usually found in either letter or legal formats for a nominal price. However, when format requirements exceed these sizes, there is a considerable price jump for larger-format machines that can output up to 33 cm by 48 cm (13 inch by 19 inch) pages.
The "hand" of the print can vary, but most laser transfer images have a synthetic plastic feel caused by the polymer coating that transfers along with the toner, although there are continued advancements in coating technology that have improved this aspect. Also, as with inkjet transfer, trimming is required with some papers.
Newer papers available on the market have unique coating chemistries that only release from the paper where toner has been applied, thus greatly reducing or eliminating the clear window effect. Solutions such as these are providing a way to decorate dark garments with laser transfers. However, the process involves a multi-step procedure whereby a white base is incorporated to provide the necessary opacity on dark fabric.
Laser transfer will work on cotton, cotton/poly blends and polyester garments, but dye migration can be an issue. A basic shopping list for laser equipment and supplies will include a laser copier or printer.
A desktop laser printer cost ranges from $500 to $10,000. A high-end laser copier may have a larger price range ($1,500-$150,000) because of the increased speed capabilities and adjustment possibilities offered as well as the technological elements of high-end equipment. A heat press ($500-$3,000), transfer paper (30 cents-$1/standard letter sheet for light garments; 60 cents-$1.50/standard letter sheet for dark garments) and toner (2 cents-25 cents/transfer) also are needed.
Laser transfers can be printed extremely fast and provide the ability to reduce inventories. They are relatively inexpensive per transfer, and do not require a huge lead time prior to printing a transfer. The same equipment can be used for light and dark shirt transfers (only the paper changes).
While technological advancements continue to improve laser transfers, some disadvantages include the need for trimming, the "hand" produced, image durability when compared with other techniques and the clear window caused by insufficient trimming.
Here are some key points to remember when considering inkjet and laser transfer technology:
The finished transfer has virtually no "hand," and the image durability is excellent. The technology is perfect for high-margin customization, certain sporting uniforms or jerseys, performance apparel or any application where photo-realistic images are needed and durability a top priority.
Dye sublimation is not limited to decorating garments. Many products such as ceramic tile, mouse pads, mugs and plates can all be decorated using practically the same equipment, so generating multiple lives for dye sublimation is quite easy.
There are two important factors that make dye sublimation unique. When high temperature is applied, it causes the dye sublimation ink to change from a solid to a gas, without passing through a liquid state. Simultaneously, when heat is applied, the polyester molecules in the fabric open to receive the gaseous dye. When the heat is removed, the polyester molecules close, resulting in a dyed polyester fiber with no "hand" on the surface.
The technology works primarily on polyester and special polyester coatings applied to the surface of an object. But there are upcoming developments for dye sublimation transfers to cotton fabric. For those of you who have experienced dye migration when screen printing polyester garments, dye sublimation is similar to when a red polyester garment reaches a temperature high enough to open the molecules to release the dye right into your nicely printed white ink.
Dye sublimation will produce fantastic color on white and light colored fabrics, so if color is critical, this is one of your best choices. Unfortunately, if you want color on a black fabric, you need to start with a white fabric and dye sublimate it black. For those designs in which color isn't critical, dye sublimation provides unique and acceptable results on darker fabrics.
Dye sublimation transfer paper has a unique coating that is designed to hold the ink until it sublimates to the fabric. Because dye sublimation is very diverse in the applicable product range, there are two types of dye sublimation transfer papers: cellulose and clay-based. Each is appropriate in certain instances.
Different papers work best with their specific application, so it's important to consult with your supplier when choosing a paper for open-substrate (textile) or closed-substrate (ceramic, metal) materials. Dye sublimation ink can be formulated in an aqueous, solvent or oil-based carrier. Most decorated apparel shops use aqueous systems.
Heat press parameters for dye sublimation usually are set between 196°C-218°C (385°F-425°F) for 35 to 55 seconds on textile substrates, and up to 15 minutes for hard substrates such as ceramic tile. When shopping for a heat press for use with dye sublimation, be sure it will reach the desired temperature to ensure a quality transfer.
The shopping list for dye sublimation equipment and supplies includes:
As indicated previously, dye sublimation offers excellent durability, image detail and color vibrancy. The finished print has no "hand," which makes the feel second to none. The technology is well-suited for popular newer trends in urban fashion and performance/wicking fabric markets. Additionally, dye sublimation offers the potential for product diversity that can benefit a company since all of their business will not be in one product type.
The drawbacks of dye sublimation include higher cost of inks and a limited, more expensive apparel choice. Nevertheless, niche markets that match technology with need do exist and some offer a handsome return. For example, outdoor work crews (construction, landscaping, etc.) are benefiting from wicking fabrics by staying dryer, cooler and are more productive than when wearing a hydrophilic cotton shirt, which absorbs perspiration and becomes heavier.
One final difficulty some dye sublimation users experience is color reproduction and predictability which can be a challenge without the proper knowledge, use and understanding of color management, ICC profiles and device calibration. Once these management systems are incorporated and used, dye sublimation is a top contender for color vibrancy, durability and image detail. Newer urban fashion trends use dye sublimation and are generating a new wave in fashion apparel.
Heat-applied vinyl is perfect for team uniforms, names, numbers and similar needs that provide extremely durable graphics that may outlast the garment. The overall "hand" will vary based on the material used. It is, after all, a film of vinyl or other material applied to the garment.
The process involves creating a design in a graphic application that will be cut. You can usually use popular programs such as CorelDRAW or Adobe Illustrator, to name two. The design is sent to a cutter/plotter which cuts the design in the chosen vinyl film. After cutting, the excess material is removed leaving only the intended design. The design is heat pressed following the application instructions provided by the supplier for that product. Typical heat press settings are between 98°C and 204°C (210°F and 400°F), depending on the type of fabric being used. The heat activates the adhesive on the material, which attaches the material to the garment for a permanent bond.
There is a diverse range of material available for most substrates, including nylon - which requires a more aggressive adhesive than a polyester or cotton material -and Lycra, which requires a material that will stretch with the fabric.
Getting started with heat applied vinyl generally requires a cutter ($500-$10,000), a computer; and a heat press ($600-$2,000). The vinyl material will range in price from one to four cents per 6.5 square cm (one square inch).
Heat-applied vinyl is relatively easy to use with a short learning curve. It has excellent durability and few fabric choice restrictions for the application. However, the technique does not allow the use of photo-realism, gradients or any type of continuous tone image. Multi-color designs are possible, though labor-intensive, because each color is cut and registered to other colors used in the design.
Another labor-intensive drawback to heat-applied vinyl is the task of "weeding" excess material from the carrier film after the design has been cut. Intricate detail in the design means time and care must be taken in weeding to keep the various components intact. Often, this process can remove design components such as the title (the "dot") above a lowercase "i" or "j."
Media costs depend on a number of factors. For light garments, 43 cm by 15 m (1.4 foot by 50 foot) rolls are about $50. Similarly sized rolls for dark garments are roughly $90. Heat press settings usually indicate a temperature of 176°C (350°F) for about 20 seconds.
Once the image is printed, the material is cut using a cutter/plotter and applied to a garment with a heat press. The durability of print-and-cut media is high, similar to that of heat-applied vinyl. The "hand" also is similar to vinyl since there is a solid film fastened to the garment. The technique is perfect for short-run, custom and personalized items providing the ability to decorate a wide range of fabrics with full-color, photo-realistic images.
Equipment needed for a print-and-cut workflow include a water or solvent-based inkjet printer ($2,000-$15,000). Expect to pay a bit more if the printer includes an on-board cutter. If it doesn't, separate cutter systems are available with starting prices starting around $2000 for a 60-cm (24-inch) desktop model. Cutters with wider widths also are available. A heat press also is needed. Films are available for a wide assortment of substrates including leather, nylon, Lycra and Spandex. They come in a range of finishes including matte and glossy.
Print-and-cut films can be designed for aqueous printers, such as Epson and solvent-based printers such as the Mimaki JV3, JV33 and JV5 as well as Roland's HiFi and AJ 1000 and HP's DesignJet 8000, 9000 and 10000. Films also are available for thermal transfer resin ribbon devices such as the Gerber Edge.
Print-and-cut media will work on just about anything. It can be easy to use but has a learning curve when using a solvent-based system. Additionally, solvent-based inkjet systems are more expensive compared with their water-based counterparts. The technology combines the durability of a heat applied vinyl with the full-color capabilities of an inkjet printer and is a good solution for dark garment decorating.
In the Part III, the final in this series, we'll explain the application of heat-set media and direct-to-garment inkjet, giving you a better understanding of how these can enhance the success of your shop.
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