What You Need to Start Printing on Performance Fabrics
Printing on performance fabrics is different than printing on fabrics made of polyester/cotton or cotton alone. In order to be successful at doing so, you need to be aware of three crucial variables that affect these fabrics differently: heat, bleed and stretch. Information and recommendations on each are noted below.
Performance fabrics and polyester are known to shrink when exposed to high levels of heat. This can be challenging to deal with since it can take prolonged exposure to temperatures as high as 325˚F in order to cure standard plastisol inks fully. Some performance fabrics could melt at these temperatures. An ink that is designed to cure at temperatures below 300˚F prevents this issue.
Bleed -- also known as dye migration -- can happen when the dyes in performance fabrics are being cured, rendering them gases. Once this occurs, the inks can migrate anywhere. This typically means they move to the ink film's top layer, tinting the print the same color as the fabric. Bleed is most often seen when attempting to work with dark garments and light inks.
There are a few ways to address dye migration. Experimenting with fabric selection is one solution, though you might be limited in your options per a customer's request. Another option is to switch to cationic dyes as they are very resistant to bleed. A third option is to cure the fabric at the lowest temperature possible without compromising a full cure. This is another reason to use an ink that has a low cure temperature.
While cotton/poly blends and cotton have some stretch, performance fabrics are designed with a great deal more. In order to accommodate this increased ability to stretch, screen printers need to choose inks that offer more flexibility than they might be familiar with.
Polyvinyl chloride (PVC) is a primary component in most screen-printing inks that have a plastisol base. In many cases, plasticizers are added to PVC to increase its fluidity. The more plasticizer that's added, the more flexible and durable the ink becomes, making it easier to stretch. Pay careful attention to the recommendations of the ink manufacturer regarding cure times. Overcuring or overheating the ink could make it more brittle. It's also important to note that this type of ink film will flex more fluidly under normal wear and tear. If exposed to adverse circumstances, such as excessive stretching or tearing, it might break down.
By taking the above three elements into consideration when working with performance fabrics, you can experience the finished results you expect. While you might also have to take into account the subtle nuances of your particular heat press, with a bit of experimentation you should be able to see superb results.