Properties of Sulpher Dyes | Characteristics of Sulpher Dyes | Features of Sulpher Dye

3. They have no direct affinity towards cellulosic fibres. To make them substantive they are to be converted in to soluble lucoform by treating them with reducing agents (Like dilute Na2S solution)
4. Sulpher dyes have good light fastness with rating about 4. This light fastness may be improved by an after treatment with metallic salt.
5. These dyes have excellent wash fastness with rating about 3-4. This good wash fastness is due to its larger molecular size & insolubility in water.
6. They are not applicable to wool due to strong alkaline condition.
7. They are exclusively amorphous, few of them show crystallinity.
8. Important for producing a wide range of shades on a varity of cotton and rayon.
9. Sulpher dyes are suitable for heavy & durable shades
10. Available in powder and soluble form
11. Sulpher dyes are cheap & easy to manufacture.

Heat and chemical resistance of Sulpher dyes are moderate to good. They have poor fastness to chlorine and are not applied to goods which are bleached with hypochlorite.

Features of Sulpher Dye

1. Amorphous Colloidal materials.
2. High molecular weight with various composition
3. Complex molecular structure –heterocyclic molecules containing Sulpher linkage.
4. Decomposed by acids, with the liberation of H2S.
5. Characterized by thiozine ring, containing Sulpher atom.