Immersion dyeing for polyester is one of the most difficult forms of dyeing possible. Dyeing polyester requires extremely high heat, and does not always work successfully. However, it is possible to immersion dye polyester if specific products are used. However, if you are a novice dyer, starting to dye with a cotton fabric will be a much better option. Alternatively, you can use disperse dye to iron on transfer dyes that will work for detailing on polyester. But if you are set on immersion dying polyester, this is the best way to accomplish it.
Wash the fabric in water that is at least 60 degrees C (140 degrees F). You can also wash the fabric on the stove and add 4.4 g (0.15 oz) soda ash and 5.5 ml (0.08 fl oz) Synthrapol per kilogram (2.2 lb) of fabric. This is done to pretreat the fabric so that it better accepts the dye. It removes all dirt and other imperfection that might get in the way of the dying process.
Dissolve the dye in 237 ml (1 cup) of boiling water according to the following directions: pale colourings, 1.3 g (0.05 oz), medium colourings, 3.8 g (0.13 oz), dark colourings, 7.5 g (0.26 oz), and black, 15 g (0.52 oz). Dilute the dye carrier NSC in 237 ml (1 cup) of boiling water. Use 2 tablespoons of NSC. Strain the liquid through a nylon stocking twice before using.
Use the large stainless steel pot for this step. An enamel pot can also be used. For 9 litres (2 gallons) of 49 degree C (120 degree F) water, add the ingredients listed below in the following measurements and order: 2.5 ml (0.08 fl oz) Synthrapol, 11 tsp vinegar or 5 ml (0.16 fl oz) Citric Acid, The diluted NSC 3.5 g (0.12 oz) of metaphos Strained and dissolved dye Stir thoroughly between ingredients.
Add the damp fabric, and bring to a boil. Stir constantly. Simmer between 30 and 45 minutes, depending on how dark you want your fabric. Stir every so often to get the dye to every part of the fabric.
While the dyed fabric is cooking, bring another pot of water to a temperature of 82.2 degrees C (160 degrees F). Take the fabric from the first fabric and put it immediately into the second pot. This is done to keep the NSC odour from the fabric, which is really smelly.
Get rid of the dye bath and refill the pot with water. Bring it up to 71.1 degrees C (160 degrees F). Put in 2.5 ml (0.08 fl oz) Synthrapol. Put the fabric into this pot, and stir for 5-10 minutes. Rinse in hot water, and then smell the fabric. If you can smell it, repeat the final two steps until the smell is all gone. Then dry the fabric as normal.
If your water is hard, it is important to use metaphos so that the dye sticks better to the cloth. For dark colours, it is especially important to use the Dye Carrier NSC, but for light colours it isn’t completely necessary.
Always dye in a well ventilated area. Wearing rubber gloves is very important for the protection of your hands. ever use an aluminium pot to dye fabrics in.