Screen Printing on Polyester T-shirts

Problems Printing on Nylon

Getting inks to properly adhere to nylon is tricky. In the process, two main problems are likely to occur: shrinkage and bonding problems. First, nylon is highly prone to shrinkage when flash cured. Secondly, some nylon products, such as nylon jackets, are treated with waterproofing chemicals. These chemicals prevent the ink from bonding to the nylon.

1.) To deal with curing problems:

a. Shorten your curing times.
or
b. Preshrink the material before printing on it. Use this method if a shorter curing time does not allow the ik to properly adhere to the material.

2.) To prevent problems due to waterproofing:

a. Remove the coating prior to printing. One method to remove the coating is wiping the fabric with rubbing alchohol. However, the alcohol may create shade variation on the fabric.
or
b. Modify your ink to enhance their ability to adhere by introducing an adhesion promoter. Use this method if shade variation is a problem with the particular fabric you are using.

Problems Printing on Polyester

Many screen printers choose to print only on printing on 50/50 cotton/polyester t-shirt fabrics. This fabric tends not to be problematic when good bleed-resistant inks are used. Problems mainly occur with 100% polyester. Problems that occur include the fabric’s potential for shrinkage when exposed to heat, the fabric’s potential for dye migration and sublimation, the ink’s inability to bond to the fabric, and matching the ink’s elongation characteristics to the fabric’s elongation characteristics.

1.) To prevent shrinkage problems:

a. Use a low-temperature when curing.
or
b. Use fast-fusing plastisols in order to reduce the total heat to which the material is subjected. These inks typically will fuse in the 280°F range, as opposed to the 320°F range commonly used for standard inks.

2.) To prevent the fabric’s potential for dye migration and sublimation:

a. Select 100%-polyester fabrics that are dyed with cationic polyester colorants. These dyes are locked into the polyester fibers and resist migration.
b. Perform a number of ink-adhesion tests to test the fabric’s receptivity to your inks such as wash testing.
c. Produce test prints at least a week in advance of the planned production run because bleeding may take a week or more to appear.

3.) To match the ink’s elongation characteristics to the fabric elongation characteristics:

a. Use a bleed-resistant, high-elongation ink. Many woven 100%-polyester materials have a high elongation factor. This type of ink is more resilient and resistant to cracking than conventional plastisols and can help prints remain intact on stretchable fabrics.
b. Match the ink’s elongation characteristics to the fabric’s elongation characteristics. Test the ink/fabric combination beforehand because not all athletic polyester fabrics stretch to the same degrees.

For both nylon and polyester it is essential that you experiment with different fabrics, inks, and curing methods to choose the best overall process.

When Organic Cotton Isn’t That Organic

Go Green. Eco-Friendly. Organic. These are all major buzzwords in society’s current vernacular. Today, more and more t-shirt companies are offering organic cotton t-shirts to their customers. Selling organic cotton t-shirts capitalize on the popular eco-friendly trend as well as giving the company the impression that they are environmentally conscious.

Are You Being Duped?

In 2015, 14,025 bales of organic cotton were produced in the United States. 19.2 million total bales of cotton were produced in the United States in the same time period. This means that organic cotton production makes up less than 1% of total cotton production in the USA. The bottom line is there isn’t a whole lot of organic cotton to go around. Even though production of organic cotton is steadily rising, it still nowhere near becoming the main source of cotton production.

100% organic cotton t-shirts are available, but they can be rare. Organic cotton costs more than regular cotton; therefore it isn’t in demand as much. More and more companies are adding organic cotton to their production process, but it is done differently than you might think.

Often time organic cotton is blended into regular cotton when producing t-shirts. This is the start of a growing trend and it will lead to more organic cotton production, but it also means the shirt could be marketed to you wrong. We have found cases where a t-shirt will be marketed as an organic cotton t-shirt, even though the shirt contains only 3% organic cotton. When you see a company advertising 100% organic cotton t-shirts, remember that they may be advertising that the t-shirt is 100% cotton, not exactly 100% organic cotton.

Organic Cotton Scam?

Is this practice just one, big organic cotton scam? Not necessarily, many of these blended shirts are popular in production. They are somewhat organic; they just are marketed to make the consumer think they are 100% organic.

The Department of Agriculture doesn’t regulate textile production once cotton has been harvested, which means that fabric may be chemically treated in the production process and still be labeled as organic. A lot of companies use dyes that are not organic. When used on organic t-shirts they make that shirt a little less organic.

What to Do?

If you are looking for a truly organic shirt make sure you know the company you are buying from. Make sure their process is totally organic, that their shirts are 100% organic and their dyes are 100% organic. We have found that the 3 Clothing Company and the Öko Box are both reputable organic clothing companies that offer you a truly organic cotton t-shirt. Both these companies use only organic cotton and their treatment process is totally organic as well. Their prices are reasonable for the industry.

Organic cotton t-shirts that are mixed with traditional cotton are not bad in anyway and are still more eco-friendly than t-shirts without any organic cotton at all. We are not trying to dissuade you from buying them, we are just telling you that if you want a truly organic cotton t-shirt than these are factors you need to be aware of. Don’t be duped, just make sure you know who you are ordering from.