Dye Migration – Screen Printing Problems
100% Polyester Garments are becoming more and more popular, recently I tested some AWD (All We Do) Pink 100% Polyester Hoodies and some Black technical garments to see which ink worked best. If you use a conventional plastisol or even a low bleed ink you run the risk of dye migration. So when printing onto a red garment with white plastisol ink after curing (and sometimes a day or two longer) you notice that the white ink has gone a shade of pink.
Why does dye migration happen?
It is quite a technical discussion but it’s basically about the way polyester is made and the way the manufactures seal the dye (in particular the temperatures that are used). The dye used turns into a gaseous substances (also known as sublimates) when the dye hits around 165 degrees Celsius, which inconveniently is around similar plastisol curing temperature. The dye then bleeds through any ink printed on top.
So what are the options:-
Set the curing temperature to be lower and continue to monitor the temperature, note that the risk of under curing increases significantly. Check the documentation with the ink to confirm curing temperature, remember to allow for thick ink deposits.
Don’t screen print onto 100% polyester, probably not really an option for any of us as we live in a competitive world
Print a grey or black under base – a proven solution but can be expensive and not that practical especially for the smaller printer
Use a specialist Polyester Plastisol ink – we sell the Best of Brands Polyester White, which works an absolute treat. Make sure you don’t over cure the ink, but in my experience using this ink reduces risk, gives a smooth opaque finish and works a treat.