March '15

For the Business of Apparel Decorating

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pressure. A standard operating proce- dure can be set up so that anyone can achieve the same result. Still, all equipment breaks. It al- ways does. When it does, what do we do? Redundancy is the best solution, but you need at least two CTS sys- tems. If you lack that much produc- tion, it's difficult to justify the second piece of equipment. In this case, it probably isn't a great idea to throw out the film technolo- gy. Instead, use it as a backup. CTS operators get so spoiled by the tech- nology that they never want to go without it. If the CTS goes down, re- verting to film is difficult. Exposure times change, the need for glass and a vacuum blanket return, fine-line res- olution isn't as good, and more. Oversized images on large-format screens is another scenario where a CTS system doesn't necessarily fit. Unless an oversized CTS was pur- chased in the first place, film may need to be run. Parts and mainte- nance are always part of the package, as well. Whether you use a toner or wax CTS system, you will probably replace heads in one way or another. On some machines, expect to spend a pretty penny for a print head, which may need to be replaced once a year or more, depending on usage or operator error. Consider keeping spare heads and other common wear items on hand. There are many considerations when choosing a CTS system. Obvi- ously, consumables and the initial cost are the most important. However, it's important to factor the time and labor savings each system offers. A higher initial cost may be quickly offset by the accuracy and repeatability the system offers, not to mention the im- provements in workflow and savings in consumables. Advancements in digital technology will continue and can only benefit the screen printer. Typically, the ink system is 100 percent solid and doesn't require a solvent to cure. As the printing ink does not air dry, most heat transfers are printed using screen printing with a vacuum bed. The transfer is then passed through a conveyor dryer to cure the ink. With the introduction of heat, the plastisol becomes a solid and, subsequently, wash resistant. In its humblest form, a textile heat transfer is an indirect method of embellishing a gar- ment. The inks are printed onto a special release paper, dried in the manufacturing process, and applied to the garment with the heat and pressure of a commercial heat transfer ma- chine. Ultimately, there are three stages the ink system goes through during manufacturing and application. 1. In the ink bucket, the material is in a viscose liquid stage and pushed through the screen. 2. As it passes through the dryer, the ink turns into a gel state. Simply, the resin reacts under heat and absorbs the plasticizers to become a solid, flexible film. Transfer inks must be partially cured to pass through the press for subsequent colors. They are stacked, cut, bagged, and then shipped to the end user. 3. Contrary to popular belief, the full cure of a plastisol heat transfer occurs during applica- tion, which is why the process is so important. Improper curing will more than likely result in a faulty application with poor wash results. Quickly test this by peeling the design from the release paper. A perfectly gelled heat transfer should peel as a solid film. Undercured transfers will break and come off on your fingers while an overcured heat transfer will be difficult or may not peel at all. This test is destruc- tive, but it saves you from ruining the more expensive garment. Remember, printing a heat transfer that looks great and lasts as long as screen printing takes both experience and skill. Shelf life is another factor that affects the washability of heat transfers. The ink is gelled but not fully cured; therefore, it's possible for plasticizers to leach out of the ink into the backing paper over time. Although most transfers are printed on a release sheet, time takes its toll. If the plasticizer migrates to the backing paper, the heat transfer will be brittle and no longer work—let alone offer durability. Generally speaking, properly produced heat transfers should have a shelf life of at least one year, but I've seen them last three to four years when kept from extreme humidity and temperature. If a heat transfer is older than one year, it's best to apply it and do a wash test. Last but not least, the proper type of heat transfer is important to ensure long-term wash- ability. Earlier, I alluded to the use of plastisol additives to modify performance characteris- tics. For example, high-stretch performance fabrics, such as nylon and polyester, require a specialty heat transfer for good adhesion and washability. To achieve these special character- istics, additives and post-applied adhesives are used in the production process. Additives can improve flexibility, dye migration, and nylon and polypropylene application. Using the right heat transfer for the substrate improves the washability and, thus, cus- tomer satisfaction. Match the appropriate heat transfer decoration with the garment's ex- pected washing characteristics. Laundry days are often not planned and happen around busy schedules. Wet garments may sit in the washer for a considerable amount of time before drying. Beyond that, the average person could process five to seven loads of laundry a week. Although frustrating and time consuming, rarely is much consideration given to separating clothes other than whites and darks, delicate fabrics, and maybe towels and bed linens. Don't expect much consideration to be given to the heat transfer you worked hard to create. You're lucky if the garment is turned inside out before it's dumped into the washtub. We've come a long way since the days of the Roman fulleries and washboards. Fast-track careers, busy family schedules, and ecological concerns have imposed new dimensions on washday. How we wash our clothes has evolved, and our industry must ensure that heat transfer embellishments will survive in our brave new world. pw pw CTS SYSTEMS continued from page 83 Graphics Hot Spot | | | | continued from page 28 20 1 5 M A RC H PRINTWEAR | 111

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