May 4th, 2018
When it comes to printing basic garments, most screen printers turn to 100-percent cotton substrates. More and more, however, customers are looking for alternatives. For that reason, cotton/polyester blends are becoming more common. These blended garments have plenty of advantages, but they also pose some of the same challenges that come with printing on fully synthetic substrates.
The Appeal of Polyester Blends
The main benefit of polyester blends is that they bring the advantages of both fabrics to the finished garment. They’re also softer and have a nicer drape, which many consumers prefer, particularly for fashion garments. In addition to their pleasant feel, polyester blends also are:
- Easy to care for.They won’t shrink in the wash like 100-percent cotton garments, and they come out of the dryer wrinkle free.
- Breathable.Like cotton garments, polyester blends are lightweight and breathable.
- Moisture wicking.Polyester blends have become popular for sports teams and as event shirts for races. That’s because they wick moisture away from the body and dry quickly, which makes them ideal performance fabrics.
- Less likely to fade or pill.These garments will continue to look great much longer than their 100-percent content counterparts.
- Durable.Polyester blends have a nice amount of stretch, which make them comfortable to wear, but it also helps them to resist ripping or stretching out of shape.
- Fibrillationresilient. On cotton shirts, fibers can break free and poke through the ink, causing the image to look faded or fuzzy. Polyester blends resist this phenomenon, so you know you’ll get a vibrant, fibrillation-free print.
- Versatile.Polyester blends can work for all kinds of prints. There are water-based inks just for polyester blends, and you can even discharge print on some polyester blend garments.
Overcoming the Challenges of Screen Printing on Polyester Blends
Polyester-blend substrates might have plenty of benefits, but there are some challenges to printing on them. Mainly, these substrates are at risk for dye migration because of their polyester component. When polyester reaches temperatures above 360 degrees, the dye inside the fabric can turn into a gas and become embedded in your ink, tinting your ink the color of the garment. You can combat dye migration with a few tricks:
- Monitor your dryer temperatures.Know the temperature of your conveyor dryer, and test it regularly. Use a donut temperature probe as you cure your ink to make sure that the ink is getting hot enough to cure but that the fabric isn’t getting hot enough to suffer sublimation.
- Test your substrate.If you’re printing on a new polyester blend substrate, test your ink and your normal printing process to see if it avoids dye migration. If the dye does migrate, you might need to consider using a different type of ink on that fabric.
- Use bleed-resistant inks.If dye migration is a problem on your substrate, use an ink or an underbase layer that’s made to prevent dye migration.
- Lay down a thin layer of ink.A thin layer of ink means you can cure your ink at a lower temperature to help avoid dye migration. Use the highest mesh count possible for your print, make sure your screen tension is where it should be, and set an off-contact distance of about 1/16-inch to reduce the thickness of your ink deposit.
- Beware your flash cure.You don’t have to worry about dye migration only during the final cure; it also can happen if you let your substrate get too hot under your flash cure unit. Make sure that you’re only flashing your image as long as the ink needs to gel. Temperature tape on your substrate can help you monitor the temperature of your polyester blend both under the flash cure unit and as your final print travels through the conveyor dryer.
Polyester blends provide plenty of benefits for screen printers, and customers are demanding them more and more. While they do pose some screen printing challenges, learning how to successfully screen print on polyester blends can benefit your customers and your business.