Auxiliaries required for dyeing with direct dye

·         Wetting agent:

                                  i.            Reduce surface tension water

                                ii.            Helps to penetrate the solution to the fibre.

·         Levelling agent:

                                  i.            To levelness of the dyeing

                                ii.            To ensuring of evenness of the dyes in the fabric

·         Electrolyte:

                                  i.            Helps in dye exhaustion.

                                ii.            NaCl used for deep shade

                              iii.            Na₂SO₄ used for medium shade.

                              iv.            Na₂SO₄.10H₂O used for medium shade.

·         Soda ash or Caustic soda:

                                  i.            Remove solubility of dye

                                ii.            Increase the effectiveness of salt

                              iii.            Increase the brightness of colored materials

                              iv.            To control p^H of the dye bath

                                v.            To strengthen the bond between dye and fibre.

Direct dye     click here

Properties of Direct dyes        click here

Classification of direct dyes          click here

Auxiliaries required for dyeing with direct dye       click here