Ever ordered screen printing ink and when it arrived, you noticed that the ink had separated? Don’t fret, the ink hasn’t gone bad! It just needs a little TLC. Let’s go over why plastisol ink may separate and what you can do it make it production-ready.
THE CHEMISTRY BEHIND PLASTISOL INK
Have you bought natural peanut butter before? When it has sat on the shelf for who knows how long, the peanut butter is stiffer and the oil has separated and sits on top. But all you have to do is mix it and it’s ready to go.
Plastisol ink works the same way. When it hasn’t been touched in a while, the ink will settle and a liquid will form on top of it. Just like peanut butter, all you have to do is stir it to mix it all together and it’s ready.
SHORT- VS. LONG-BODIED PLASTISOL INKS
Two types of plastisol ink exist — long- and short-bodied.
Long-bodied inks are a bit runnier than short-bodied ones (it tends to drip/run off squeegees and spatulas). Long-bodied plastisol inks are more likely to experience ink and liquid separation and they require more modulation before they’re ready for production.
Short-bodied inks, like FN-INK, have a higher viscosity than long-bodied inks. They aren’t as runny and it doesn’t take long to modulate them.
TIPS ON MODULATING SCREEN PRINTING INK
When it comes to modulating ink, you have a few options. You can choose your own method based on what you have and how much ink you need to mix.
USING A SPATULA
When using a small quantity of ink (like a quart or pint), stirring it with a spatula is the best route. Stir until all liquid is absorbed back into the ink.
FYI, you will achieve peak performance from plastisol ink once it hits 80°F. Stirring the ink will warm it up, but it’ll reach the optimal temperature when it’s exposed to heat radiating off a platen. After a few test prints, you and the ink will be loosey-goosey.
MIXING WITH A DRILL BIT
When mixing large quantities of ink, like a gallon or five gallons, you’ll want to pull out some power tools to help you get the job done. A drill with a mixing blade will mix the ink faster and quicker while warming it up more than you could if you mixed it by hand. Just one tip – mix slowly, you do not want the ink splattering everywhere.
Always follow the rule of thumb: mix your ink before you start printing. Your life will be smooth sailing if you follow this rule.