A recommended after-clearing procedure for polyester involves the application of a suitable reducing agent. Sodium Hydrosulphite is a highly effective clearing agent for polyester which produces brighter and cleaner shades and eliminates the possibility of contamination from unfixed dye.
When after-clearing dyed polyester, use 2 – 4% owf of Sodium Hydrosulphite at a temperature of 140° F(60°C) and run for 15-20 minutes. This is generally sufficient in most cases. The depth of shade as well as the presence of possible contaminates in the water will determine the correct amount to use. If a severe scour is required, the temperature should be raised to 180° F(82°C) for 20 minutes and rinsed well.