MAUVENE, the first to be discovered by Perkin, was a basic dye and most of the dyes which followed, including magenta, malachite green and crystal violet, were of the same type. Basic dyes dye wool and silk from a dye bath containing acid but dye cotton fibres only in the presence of a mordant usually a metallic salt that increases affinity of the fabric for the dye. Basic dyes include the most brilliant of all the synthetic dyes known, but unfortunately they have very poor light and wash fastness.
USE: Basic dyes will dye wool and silk from an acid bath and are used where brightness is of prime consideration. With the introduction of cotton dyes possessing higher fastness properties their use for dyeing cotton has diminished. Basic dyes are used extensively for dyeing cut flowers, dried flowers, also dyeing jute sisal, raffia, coir and wood (toys). With the introduction of acrylic fibre a new range of 'modified' basic dyes were perfected for dyeing of this material.
Dyeing method of Basic Dyes
1. Pre-treatment of goods
Goods→ treatment with tannin (tannin:1-10%, temp.: 90°C time:30min, Liquor ratio: 1:10-20)→ Lower the temperature to ordinary temperature (Keeping the temp. 6-12 hour)→ Dry→ treatment with tartar emetic( tartar emetic:1-3%, temp.: ordinary temp., time:10-20min, Liquor ratio:1:10)→ Rinse.
2. Dyeing procedure