Plastisol Prints

 

Plastisol Prints


Plastisol inks are made up of polyvinyl chloride resin, plasticizers, and pigments.20 According to Rutland Industries, this balanced system of solids to liquids is a finished product ready to print. Additives such as dye migration blockers, fillers, puff, and stabilizers can be incorporated into the formula depending on the final product requirements.21 These products are sold ready to use in screen-printing for all types of unit printing applications. The most common form of unit printing is garment printing.

Plastisol inks are thixotropic. That means the mixture is high in viscosity when at rest and is low in viscosity when shear or movement is applied. Shear or movement of the plastisol against the surface of the container or screen can generate heat. During mixing or printing as friction heat builds, the viscosity decreases. As temperature decreases, viscosity then increases.

T-shirt printing is most often done in a non-textile facility. Plastisol inks can be loaded with “block-out” fillers which allow the printing of designs, on dark dyed t-shirts, which are visible and completely cover the dark background. The resulting prints sometimes show an increase in stiff handle due to these additives.
Water-based pigment inks have been developed which yield a more acceptable handle. Screen drying of these water-based products present a problem of running properties similar to normal textile printing. However, the clean up of screens and equipment is done with soap and water and does not require the use of solvents which makes these products more environment-friendly.

For a plastisol ink to fully cure, the water in the garment must first be dried off, then the resin in the ink swells to react with the plasticizer to form a film. Table below details some of the variables which can impact curing of plastisol inks.

Variable

Description

Fiber type

Some fibers hold more water than others (cotton vs. nylon)

Fabric color

Dark garments heat faster than light colored garments

Garment weight

Heavier garments take longer to heat to temperature

Fabric construction

Fabrics with greater surface area will take a long time to heat

Ink thickness

Thicker prints will take longer to heat than soft-hand prints

Ink type

Specialty inks may take longer to heat then conventional inks

Room temperature and humidity

Ambient conditions may impact