Impressions - March 2020 - 29

Be prepared to discuss
graphic options that
work with specif ic
substrates for the
best outcome when
decorating synthetics.

When you receive a request to print on a synthetic or performance
garment, consider the differences in the process before providing a
quote. Done correctly, it may cost more and take more time.
Points to consider include:
* Inks used for printing on high-polyester blended apparel are
more expensive.
* Design setup usually is more time consuming.
* The dryer belt will require a slower speed.
* Temperature must be exact and lower than when printing cotton.
* More screens are required because the temperature is lower.
* You won't be able to immediately stack garments after processing.
These extra steps add time to the process, and require more labor
and money - which will affect the garment's price.

You can choose from different ink platforms when printing on highpoly synthetic garments:
* Low-Bleed: These inks are ideal for 50/50 blends with low
synthetic content.
* High Poly: This ink is ideal for 100% polyester and highpoly-content fabrics. Its viscosity is thicker and super opaque.
* Carbon Base Gray/Black: This ink is used as an underbase
to absorb the fabric's dye when it gasses. The ink reduces or
blocks the fabric dye from filtering through to the ink surface.
* Low-Cure: These inks have a low blocking agent, but they
cure at 250˚F-280˚F and are ideal for heathers, tri-blends and

substrates requiring detail and a great hand. The low-cure quality enables heat reduction - which means no more scorched
garments - and energy reduction, which saves money.
Standard plastisol inks must cure at 320˚F, so you can't use them
on synthetic apparel without blockers. The key is to keep the garment temperature less than 280˚F to prevent dye migration, melting
or scorching.

Mesh Count: Using a 110-160 mesh will allow the best coverage
and opacity for base screens. Top inks can be printed using 160-230
mesh and 110-160 mesh can be used for a white overprint.
Viscosity: Stir the ink prior to production to reduce viscosity and
help push it through the mesh, resulting in a better print surface.
Squeegee Pressure: Use the least amount of squeegee pressure.
Keeping the ink on the fabric surface will help with opacity, hand and
migration. Fibers working up through the ink increases the probability of dye migration. However, using too much pressure will push
the ink through the fabric, leaving an undesirable feel.
Tapping/Smoothing Irons: Polyester inks are thick; hand is just
as important as reducing migration when printing on performance,
heather and tri-blend fabrics. Smoothing the ink surface will improve
the print's quality and feel.
In the first station, use a tapping/smoothing screen to lay down
any fibers. Print the base screen and flash, but instead of a cooldown
station, add another tapping/smoothing screen to smooth out the
ink. Then, print the top-color inks. Using two white screens is recommended.
Screen Tension: Keep ink on top of the fabric by having the
proper screen tension. If screens are tight and you use a thin thread
diameter, the mesh openings will allow better laydown. You won't
need as much pressure, and registration will be cleaner and tighter.
You also can achieve a smoother surface with less mesh texture in
your ink. Poor screen tension will result in registration issues, forcing you to apply more pressure to get the ink through the screens.
However, increased pressure will drive the ink through the fabric
and allow fibers to work themselves to the top of the ink, causing
more dye migration.
Flashing and Curing: The most important step when printing on
high-polyester synthetic fabrics: Don't over-flash or over-cure garments.
Migration occurs at about 270˚F, so use inks with a quick flash point.
Flash only for a few seconds and keep temperatures below 200˚F.
Also, reduce the number of flashes in your design; don't flash if it's
not required. Use inks that cure at a lower temperature - around
250˚F-270˚F. Slow the dryer's belt speed to ensure the ink is cured
and don't exceed the curing temperatures.
No Stacking: Don't stack garments until they are completely cool.
Pressure and heat can accelerate any migration. Fans and long cooling
stations on dryers will expedite the process.

Be prepared with different design options depending on your customer's request. A big, bold design may not work on a lighter-weight
synthetic garment; the ink will be super heavy and dye may migrate.
Heathers and tri-blends are good examples of super-soft, lightweight
garments on which heavy inks aren't very appealing.
One option is to rethink the artwork, open up the design or use
more of the garment's color instead of putting so much ink on the
garment. You also can recommend changing the substrate. Instead
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Impressions - March 2020

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