RichestChemical company limited

Introduction

        Basic dye has been applied to dye on silk for a long time. It has beautiful colours on silk. Because of bad fastness, its applications on wool and cotton have substituted for acid dye and reactive dye.But the prices of basic dyes are very cheap, so basic dyes are very cheap, so basic dye has widely still applied up to now.

Dyeing Procedures

Dissolving the dyestuffs:

The dyestuff is pasted with an equal weight of 30% Acetic Acid and dissolved by pouring boiling water onto the paste, for Auramine O the temperature should never be over 60°C, strring until is dissolved thoroughly.

1.   Application to cotton, viscose rayon and other cellulosic fibres:

(1) Mordanting with tannin:

The material to be dyed should be mordanted with 1-6% tannin solution by entering the goods at 60-70°C for about 30 minutes, and then steeped overnight in the cold bath.

(2) Fixing

After mordanting, the goods should be very well squeezed or hydroextracted without rinsing. The goods are then treated with 1-3% tar-tar emetic solution for 30 minutes and well rinsed.

(3) Dyeing

The dye bath is charged with 3-5% acetic acid 30%. The good are dyed for 10 minutes under ordinary temperature, then the bath is heat slowly over a period of 15 minutes up to 60-70°C, maintaining at this temperature until the dye - liquor is exhausted. Finally the goods should be well rinsed.

2.   Application to wool:

Dyeing is conducted either in a neutral bath or in a bath containing 1-2% Acetic Acid 30%. The goods are dyed at 80-90°C for 30 minutes.

3. Application to Silk:

The dyestuffs should be added to the dye - bath in 2 or 3 portions, and the dyeing is commenced cold for 10 minutes. The temperature is slowly raised to 60°C and kept dyeing at this temperature for 20-30 minutes.