September '19

For the Business of Apparel Decorating

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Page 38 of 70

P rinting on today's athletic gar- ments can be a daunting task. There are so many different types of fabrics, treatments, dying tech- niques, and ink types. How is a printer supposed to make sense of it all, and not just avoid printing on these garments altogether? It is challenging, as most of the time it is left up to the printer to figure out how to print on the garment, make it look nice, and have no bleeding or wash issues. Modern fabrics can be challenging to decorate. You see poorly dyed polyester garments, dye-sublimated garments, and blends that have temperature-sensitive fab- ics like Lycra/Spandex and viscose rayon. All of these fabrics have a tendency to bleed or melt if exposed to high dryer tem- peratures. The best thing for a decorator to do is to control the process and temperature, choose the right ink, and eliminate variables. GETTING TO WORK When printing onto polyesters, blends, or anything else that may have a tendency to bleed, you want to ensure your process is correct. You want to make sure that you have a good stencil on the print side of the screen (typically at least two coats of a high solids emulsion), proper off-contact, and increase the squeegee angle. The key here is to get a nice layer of ink to lay down on top of the garment, not pressed through the fibers of the garments. Think of it like the roots of a tree. A tree does a better job of absorbing water when it has a strong root system. If it does not have a solid root system, it is difficult to absorb water. The same is true when it comes to the dye in a garment and the ink. The better job you do keeping the ink on top of the garment and not penetrating it, the better chance your ink has at blocking the dye. One key to ensuring that your garment does not melt or bleed is to control the temperature. The first step in which your garment gets exposed to heat is the flash unit. Over flashing is a big problem and can lead to melted shirts and bleed. The key is to not have your flash so hot that the temperature of the garment reaches more than 280 degrees F. You should be flashing just long enough to eliminate ink transfer, not so long as to fully cure the ink. To help eliminate over flashing, you may need to adjust your flash times on longer runs as your platens heat up and less energy is needed to flash your print. The second step in temperature control is to keep your dryer temperature under 300 degrees F. You can test the fastness of the dye by using a dye test kit to determine what temperature the dyes in the garment will release. Some temperature sensitive fabrics and more poorly dyed garments may require your oven temperature to be as low as 280 degrees F. For those deco- rators that have short dryer tunnels and/ or inconsistent heat control, this can be a real challenge. You must keep your oven temperature below 300 degrees F and ad- just your belt speed to give your printed garment enough dwell time in the oven to ensure proper cure. You cannot speed up the process, otherwise you will get bleed or under-cured garments. This may mean that you need a dryer with a longer tun- Printing Athletic Apparel A A R O N B L A N K 3 4 P R I N T W E A R S E P T E M B E R 2 0 1 9

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