Special effects give garments unparalleled visual and tactile appeal. This article showcases effective methods for boosting the value of printed apparel.
High-solids inks Some high-solids or opaque water-based inks can work well on some polyester and most polyester/cotton blends. The potential for dye migration is minimized because these inks do not contain a true plasticizer and because the dryer temperatures can usually be a little lower than what would be required for a standard plastisol. However, you must test on a case-by-case basis before proceeding with production quantities. The graphic pictured here was printed with a high-quality, high-solids, water-based ink on a polyester T-shirt. The inks prevented dye migration issues on this particular fabric quite well, and the print’s quality and integrity have held up over time.
Discharging on blends Surprisingly, discharge fluids will occasionally work on polyester/cotton blends. These formulations can yield very unpredictable results, but they are proven in production in a noteworthy number of instances. Discharge fluids are not recommended for this specific use, so you’ll need to test carefully. This example shows an opaque or highly pigmented white discharge water-based ink printed on a 60/40 polyester/cotton fabric. It was flashed and then printed a second time. The discharge removed enough of the dye in the cotton portion of the fabric that the white pigment in the ink was able to block the remaining dye in the polyester portion of the fabric.
PVC-free HD You can make these PVC-free inks into high-density inks without much difficulty. These examples show multiple layers of PVC-free, high-density inks printed through coarse mesh (250-micron stencil thickness).
High-density designs Polyester and polyester/cotton blends bring many new challenges to any specialty garment print. The dyes in the fabric can migrate through the printed ink, thereby changing the color of the ink. Dye migration can take place—or worsen—over time. The cure temperatures of most inks also contribute to the effect because dye migration is often a heat-related issue. High-density inks can help prevent dye migration on some fabrics because of their high solids content and thick ink film. In this example, a high-density ink was printed in multiple layers on a 60/40 polyester/cotton blend through coarse screens coated with thick stencils. If you’re in doubt about dye migration, then consider using a low-bleed underprint. Also note that you must configure your dryer to cure the high-density ink formulation completely.
Semi-gloss style In this example, two layers of a clear, thickened, PVC-free plastisol were printed over a standard, PVC-free graphic to simulate a thick, semi-gloss patch. Low mesh counts and thick stencils were used for both clear screens.
If you’re looking to cash in on the renewed interest in special-effects printing, keep in mind that customer demands for PVC-free inks and the increasing prevalence of polyester fabrics can limit the possibilities. New inks designed to meet these requirements also place the burden on printers to test and document their results and adjust to the corresponding changes in techniques and fabrics. As with any new challenge, this can make for an exciting opportunity to come up with innovative, new solutions, new printing methods, and product development.
Michael Beckman is president of MB Screen Printing Inc., which has been providing a variety of technical services, seminars, workshops, and speaking engagements for the textile printing industry for many years. Michael is responsible for the de-sign and development of many new screen-printing products and techniques. MB Screen Printing Inc. has recently been involved in a number of long-term projects establishing and managing factories throughout the world. He can be contacted at firstname.lastname@example.org
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