Reactive Dyes [ Application, Characteristics, Reactive Groups & Area of Applications, Structure, Properties, Dyeing Method & Experiments]

PART # 1        

1. APPLICATION OF REACTIVE DYES:

Reactive dyes are used for dyeing and printing of cellulosic fibers such as un-mercerized and mercerized cotton and rayon fibers (viscose and cuprammonium rayon), wool, silk, nylon, blended materials and union fabrics of polyester/cotton, polyester/viscose, etc. These dyes are highly important especially for dyeing and printing of cotton.

2.CHARACTERISTICS:

Advantages:

• Brilliant shades.
• Excellent wet fastness (fastness to water, washing, etc.).
• Comparatively easy dyeing and printing.
• Generally, high solubility.
• Applicable to a wide range of white and colored discharge printing.
• Conventional dyeing apparatuses can be used.

Disadvantages:

• Most of the reactive dyes are poor in chlorine fastness.
• Some of the dyes are low in fastness to light and perspiration-light.
• With some dyes (such as di-chlorotriazine dyes), the dye materials undergo change with the lapse of time, leading to lowered wet fastness.
• In the exhaust dyeing process, fixation degree is relatively low, so that the color content in the waste water is high.
• In the exhaustion process, a larger amount of salt is required.
• Owing to the lower substantivity of the dyes, the dyeing are largely influenced by the liquor ratio, therefore, the dyes are not suitable for long liquor dyeing.

3. REACTIVE GROUP & THEIR AREA OF APPLICATION:

1. Reactive Group: [VS type] Sulfatoethyl-Sulfone (Vinyl-sulfone)

Year of Introduction: 1957

Area of Application: For Exhaust Dyeing, CPB, Continuous Dyeing & Printing

2. Reactive Group: [DCT type] Di-Chlorotriazine

Year of Introduction: 1956

Area of Application: For Exhaust Dyeing

3. Reactive Group: [MCT type] Mono-Chloro-Triazine

Year of Introduction: 1957

Area of Application: Exhaust Dyeing, Continuous Dyeing & Printing

4. Reactive Group: [MFT type] Mono-Fluro-Triazine

Year of Introduction: 1978

Area of Application: For Exhaust Dyeing

5. Reactive Group: [TCP type] Tri-Chloro-Primidine

Year of Introduction: 1960

Area of Application: For Exhaust Dyeing (Hot), Continuous Dyeing & Printing

6. Reactive Group: [DFCP type] Di-Fluro-Mono-Chloro-Primidine

Year of Introduction: 1970

Area of Application: For Exhaust Dyeing (Cold), Continuous Dyeing & Printing

7. Reactive Group: [FMCP type] Fluro-Methyl-Chloro-Primidine

Year of Introduction: 1980

Area of Application: For Continuous Dyeing & Printing

8. Reactive Group: [DCQ type] Di-Chloro-Quinoxizaline

Year of Introduction: 1980

Area of Application: For Exhaust Dyeing

9. Reactive Group: [VS+MCT type] Bi-Functional

Year of Introduction: 1980

Area of Application: For Exhaust Dyeing, CPB, Continuous Dyeing & Printing

10. Reactive Group: [MCT+MCT type] Bi-Functional

Year of Introduction: 1968

Area of Application: For Exhaust Dyeing

To Be Continued................