*8.1.2 Method 2*

In this method the photochromic dyes can be applied as a disperse dye on polyester fabrics by exhaust method of dyeing [43]. The dye is pasted with acetone and then stirred in water with dispersing agent (1%) keeping the M:L ratio of dyeing 1:50.The pH of the dyebath is maintained between 4.5–5.5.The aqueous dyebath is boiled to evaporate acetone, subsequently temperature is raised to 120°C and dyeing is done at this temperature for 45 minute. After dyeing reduction clearing treatment is given at 70 °C for 20 min. and finally sample is soaped, rinsed and washed.

#### **8.2 By continuous dyeing**

In this method photochromic dyes are dissolved in acetone and then mixed with binder solution and padded with padding mangle at appropriate pressure. After padding fabric is dried at 80 C and cured at 140 C for 3.0 minute in hot air oven or stenter machine [44].
