Troubleshooting Common Issues with Plastisol Screen Printing Ink
Plastisol is favored by screen printers for its ease of use. Nevertheless, there are some problems that can crop up when you’re screen printing with plastisol ink. Here is our list of the top 10 most common problems associated with plastisol screen printing and how to solve them.
Problem 1: Prints that wash away
If your screen prints are washing away, your ink isn’t being fully cured. The best way to resolve this is to check your curing temperatures: Use a heat gun, donut probe or temperature tape to see how hot your ink is getting during the curing process. Adjust your dryer temperature and speed to get the ink to the manufacturer’s recommended temperature.
Problem 2: Lack of opacity
Is the color of your substrate showing through your print, making your image seem dull? There are several ways to make your plastisol screen prints more opaque. First, lay down a white underbase. You can also try to lay down a thicker ink deposit. To achieve that, don’t use an ink additive, print through a lower mesh count, create a thicker stencil and print with a larger off contact.
Problem 3: Dye migration
Dye migration occurs when you print a light color ink on a darker synthetic substrate. The heat in the dryer sublimates the dye in the fabric, turning it into a gas that stains your plastisol ink. Use an ink or ink additive that’s made to combat dye migration, and cure your ink at a lower temperature for a longer period of time.
Problem 4: Prints that peel away from the substrate
If your prints are peeling away from the substrate after curing, there are two likely causes. The ink is either undercured or the improper ink has been used for the substrate material. To be sure the ink is cured, check the temperature of the ink during the curing process. To make sure you’re using the right ink, check the manufacturer’s recommendation to ensure the ink you’ve chosen is suitable for your substrate.
Problem 5: Ink that won’t stick to your underbase
Underbases are recommended for increasing the vibrancy and opacity of your print. Sometimes, however, the layers of colored ink in your print will peel away from the underbase. The problem occurs when the underbase is fully, rather than partially, cured. An underbase should be flash cured so that it gels, rather than solidifies, so that it remains tacky to help with the adhesion of the additional layers.
Problem 6: Fibrillation
Fibrillation occurs when a substrates fibers break through the ink deposit. It causes the print to have a fuzzy, and sometimes faded, look. Prevent fibrillation by using a high quality ink and laying down a thicker deposit. A clear or white underbase also can mat fibers down and hold them in place so they don’t interfere with your final image.
Problem 7: A stiff hand feel
Plastisol inks aren’t known for their soft hand feel, but you don’t have to resign yourself to a plastic hand feel when you print with plastisol. Use a soft-hand additive, design an image that makes use of negative space and employ a few tricks to lay down a thinner layer of ink.
Problem 8: Ghost images
One plastisol problem that puzzles many printers is ghost imaging, when the image you print appears on the back of a substrate, usually after curing. This phenomenon usually occurs when printing on 100 percent cotton substrates, and it’s caused by using low-bleed inks meant for printing on synthetic substrates. These inks contain a bleaching agent that can remove the color from the back side of a cotton shirt during curing. Use the right ink to avoid this problem.
Problem 9: Cracked ink
Cracked prints can lead to seriously disappointed customers. Here again, the problem tends to be undercuring ink. To avoid sending customers home with prints that will crack, test your prints by giving them a gentle tug after they’ve been cured; the shirts will crack if the ink hasn’t come to proper curing temperature.
Problem 10: Sticky prints
Do you pack your finished prints only to find that they’ve stuck together on the shelf or in the box, potentially causing damage? You didn’t give your plastisol enough time to cool. The heat from your dryer causes the ink to cure and form a permanent bond, but if you don’t give the ink adequate time to cool after curing, your prints can stick to everything they touch.
Plastisol ink remains one of the easiest options for screen printing, but that doesn’t mean it isn’t without its problems. Fortunately, nearly all problems that come when screen printing with plastisol inks can be resolved with some simple troubleshooting!