Reactive Dye’s Innovation: Non-Urea Printing Part 2
As we’ve been discussed the Part 1 dated on Nov 13, 2017, our data shows the non-urea or low urea printing can be reached the depth effect on cotton fabric. This time let’s discuss about the urea substitutes.
We all know the viscose printing needs a lot of urea as wetting agent and solvent because it helps color fixation during steam process.
The urea will be fully removed during washing after finishing reaction and all the urea in color paste will completely get into effluent disposal system.
To reduce urea emission, many factories are using urea substitutes.
The substitutes mainly include dicyandiamide or alcohol ether agents.
So far, the world known companies such as Huntsman, KAYAKU and ICI, their urea substitutes main component is dicyandiamide and our local companies prefer alcohol ether agents.
1. Dicyandiamide (NH2CN2): it has similar structure and absorbency functions as urea. However, it is hard to dissolve into water and has too much nitrogen element that will still cause the water pollution.
2. Alcohol ether agent: they have couple substitutes such as diethylene glycol, triethylene glycol, thiodiglycol and etc.
For the above items have good absorbency function however, the triethylene glycol is dangerous it will cause explosion if its concentration is more than 10mg per cube in air. Some substitutes after reaction will produce mustard gas.
Both of them are not perfect or safe substitutes to instead of urea.
We’ve been done lots of tests for the urea substitutes but did not get the ideal result. Therefore, our company decide to focus on the non-urea reactive dyes not urea substitute. Our final goal is we do not need to use urea and achieve color fixation and color fastness.