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Testing Polyester Fabric for Dye Migration – Part One

By Rick Roth

Ok, you have a shirt and it has some or all polyester content, what do you do? Too many printers I see P & P it. “P & P” is what I call “print and pray” and no matter what religion you do or don’t follow, I would keep prayer out of your printing operation. You need some science and here it is. You can test the fabric and get some idea of what the appropriate measures will be to print the fabric properly.

Can’t you just ask the garment manufacturer how to print their fabric? No, usually not. They just make the garments, and most leave it to you to figure out how to print it. That is changing and two of the companies we work with, Hanes and San Mar both are working increasingly to give the printer the information they need to properly print their garments. However, most times you are flying blind in the realm and there is a great deal at stake. If you print even fifty nice red hoodies and two weeks later the red dye gets into the white ink and turns it pink and the customer returns them, that has a hefty price tag. Make that 10K hoodies and you are financially ruined…

Dye migration is when the color or some part of the color in a garment migrates into the ink you printed. There are measures you often can take to stop this process, but first you need to know if it is going to happen and if so how badly. You can do a test to see what you are dealing with and that is where we will start our series on printing on polyester.

Here is the test in words and then followed by some photos.

 

  • Put the fabric you are going to test on transfer machine. Make sure the transfer machine has been turned on long enough to be fully warmed up.
  • Apply a quarter size spot of plasticizer. We use Rutland non curable viscosity reducer. Basically you want only half of the plastisol equation, all plasticizer, no resin.
  • Lay a piece of white cloth or pellon on top of the plasticizer.
  • Heat press the white fabric on top of the fabric you are testing. Do it at 320 F (160 C) for 30 seconds.
  • Check the white fabric.  What does that stain look like from where it was on top of the plasticizer.  The more stain present on the white fabric the more severe the dye migration you will get when you try to print that fabric.
  • All polyester dye colors will migrate at least a little bit, this test just lets you know how severe the dye migration is going to be.
  • Test some fabrics you have printed before. Since there is always at least a tiny bit of migration, you need to get a feeling for how much stain is indication of how bad the migration is going to be. If you do this testing often enough and see how things then print, you eventually get a very good idea of how badly any particular fabric is going to have a dye migration problem and you can take the appropriate measures.
Plasticizer, ask your ink manufacturer for a non-curable reducer.
Plasticizer, ask your ink manufacturer for a non-curable reducer. The Rutland product changed since this artcle was first written is now called stock # EA0011 NPT Reducer #2.
Step one - take a dropper of plasticizer
Step one – take a dropper of plasticizer
Step two - apply plasticizer to the fabric you want to test
Step two – apply plasticizer to the fabric you want to test
Step three - apply about enough to make a circle the size of a quarter
Step three – apply about enough to make a circle the size of a quarter
Step four - cover the plasticizer spot with a square of white fabric
Step four – cover the plasticizer spot with a square of white fabric
Step five - apply standard pressure and heat the square and the test fabric at 320 degrees F which is 160 degree C. Do it for 30 seconds.
Step five – apply standard pressure and heat the square and the test fabric at 320 degrees F which is 160 degree C. Do it for 30 seconds.
Step Seven - Examine the white fabric and the amount of color that comes out of the test fabric into the white fabric indicates the severity of dye migration you are likely to experience. In this case, quite a bit of problem.
Step Six – Examine the white fabric and the amount of color that comes out of the test fabric into the white fabric indicates the severity of dye migration you are likely to experience. In this case, quite a bit of problem.

 

Comments

    1. Yes, it will also tell you about the dye migration that might occur with a 100% cotton garment dyed shirt. However, two things to be aware of as well:
      1. sometimes pigment dyes are put on excessively or not heat set and they can get in the ink no matter what you do. In this case you often see the dye on your hands and everywhere.
      2. Be careful as using some inks that are made for blocking dye migration will cause ghosting on 100% cotton shirts.

      Reply

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