Sulphur Blue 7

Application Features

Colour Fastness Test

Sulphur Blue 7 (Sulphur blue BRN) alias vulcanized and light-resistant blue.

The dye strength is 150%, the appearance is a navy blue uniform powder, the color light is similar to the standard product, the fineness (80 mesh sieve residue) ≤ 5%, the moisture ≤ 5%, the strength is standard 100% ±3% of the product. Free sulfur content ≤1.0%.

Sulfur blue is insoluble in water, soluble in sodium sulfide solution is greenish brown, blue-purple in concentrated sulfuric acid, dark blue precipitate after dilution.

All in sodium hypochlorite solution Faded, dark purple in the presence of concentrated sulfuric acid.

Sulphur Blue 7 Use condition

1. Sulphur blue BRN is suitable for the dyeing of cotton, hemp and viscose, and also for the dyeing of cotton blended fabrics.

2. The color of the dyeing is bright, Sulphur blue 7 is dissolved by hot alkali sulfide, the temperature is 60~70 °C, the leveling property is medium, and the pH value is preferably 8.5~9.

3. After dyeing, oxidize with air or sodium perborate.

4. When dyeing cotton blended fabrics, vinylon is darker and redder than cotton.

5. the Sulphur Blue 7 is Poor stability when dyeing, easy to oxidize to produce red edges, crosspieces, erythema, etc. When dyeing cotton cloth, add baking soda (40%~60% of 50% sodium sulfide) to help dye reduction The color is more vivid, which can save about 10% of the dye, and can eliminate the red edge rickets. The baking soda should be added at a temperature less than 50 °C to prevent foaming and overflow of the dye.

6. When using the continuous cylinder, add 10~18g/L salt in the dyeing bath to make full use of the dye. The cloth should be kept flat when rolling, and twice the dye amount of glucose can be used as the reducing agent. Then, 500 g of sucrose and 180 g of sodium sulphide were used to prepare a 100 L solution, and watering was performed to improve the premature oxidation phenomenon.

7. If the reciprocating dyeing machine or hand-dyed cyan yarn is used, the amount of vulcanized alkali should be increased. The dyeing process should not be too fast, and the oxidation should not be too fast. Immediately after dyeing, the dyeing residue should be washed with water. Alkali.

8. Hand-dyed yarn, the bath ratio is as large as possible, and Sulphur blue BRN is better to completely immerse the cotton yarn in the dye liquor.

9. After dyeing, if you use hydrogen peroxide or sodium perborate as oxidant, you can get more vivid colors, but the wet processing fastness is poor, the soaping fastness is also reduced, and the color light is also red. Treating the dye with fixing agent can improve the washing Degree and light fastness, but the shade is slightly darker.

10. Vulcanized and light-resistant blue is mainly used for the dyeing of navy in corduroy. Sometimes it is also added with a small amount of vulcanized yellow brown or yellow to dye dark gray.

Precautions

Sulphur Blue 7 is easy to absorb the moisture in the air and deliquesce agglomerates and oxidizes and deteriorates. It should be stored in a ventilated and dry place. This dye is a banned dye. It can be replaced by vulcanized dark blue 3R.

Mainly used for cotton, hemp, viscose fabric dyeing, and can also be used to top and viscose fiber protoplasmic coloring. Sometimes also used in leather and paper dyeing.