Direct Blue
Direct Blue: Premium Dye Solution for Industrial Applications
Direct Blue is a high-performance synthetic dye widely used in textile, paper, and leather industries. Our formulation delivers exceptional color fastness and consistency across various materials.
Technical Specifications
- Chemical Name: Direct Blue 71
- CAS Number: 4399-55-7
- Appearance: Dark blue powder
- Solubility: Soluble in water (50 g/L at 20°C)
- pH Value: 6.0-8.0 (1% aqueous solution)
- Light Fastness: 4-5 (ISO 105-B02)
- Wash Fastness: 3-4 (ISO 105-C06)
| Property | Value | Test Method |
|---|---|---|
| Molecular Weight | 992.81 g/mol | HPLC |
| Melting Point | 300°C (dec.) | DSC |
| Absorption Max | 598-602 nm | UV-Vis |
| Moisture Content | < 5% | Karl Fischer |
| Ash Content | < 1% | Gravimetric |
Application Guidelines
For optimal results with Direct Blue, follow these application parameters:
- Recommended dyeing temperature: 80-95°C
- Typical dyeing time: 30-60 minutes
- Optimal pH range: 7.0-10.0
- Salt concentration: 20-80 g/L
- Standard concentration: 1-3% owf (on weight of fabric)
Direct Blue FAQ Section 1
Q: What materials can be dyed with Direct Blue?
A: Direct Blue is primarily used for dyeing cellulosic fibers like cotton, rayon, linen, and paper. It can also be applied to leather and some synthetic fibers when used with appropriate auxiliaries. The dye shows excellent affinity for materials containing hydroxyl groups.
Q: How does Direct Blue compare to other blue dyes in terms of fastness?
A: Direct Blue offers superior wash fastness compared to most acid dyes and better light fastness than many reactive dyes. Typical fastness ratings are: wash fastness 3-4, light fastness 4-5, and rub fastness 3-4. For specific applications requiring higher fastness, we recommend using after-treatment with cationic fixatives.
Packaging Options
| Packaging Type | Weight | Dimensions |
|---|---|---|
| Plastic bags | 25 kg | 60×40×25 cm |
| Fiber drums | 50 kg | Ø50×70 cm |
| Carton boxes | 1 kg | 20×15×10 cm |
Storage & Handling
- Store in cool, dry conditions away from direct sunlight
- Maintain storage temperature between 5-30°C
- Keep containers tightly closed when not in use
- Shelf life: 24 months from production date
- Use appropriate PPE when handling (gloves, goggles, dust mask)
Direct Blue FAQ Section 2
Q: Can Direct Blue be mixed with other dyes?
A: Yes, Direct Blue can be combined with other direct dyes to create custom shades. However, compatibility should be verified through small-scale testing as different direct dyes may have varying exhaustion rates and affinities. For mixtures with other dye classes (reactive, vat), specialized application methods may be required.
Q: What safety precautions should be taken when using Direct Blue?
A: While Direct Blue has low acute toxicity, proper handling procedures should be followed: avoid inhalation of dust, prevent eye contact, and use in well-ventilated areas. The dye is not classified as hazardous under GHS, but material safety data sheets should always be consulted before use. Contaminated equipment should be cleaned thoroughly after use.
Quality Control Parameters
| Parameter | Specification | Tolerance |
|---|---|---|
| Color Strength | 100% (vs standard) | ±3% |
| Shade | Standard blue | ±0.5 CIELAB units |
| Water Content | ≤5% | +0%/-1% |
| Insoluble Matter | ≤0.5% | +0%/-0.2% |
Direct Blue FAQ Section 3
Q: How does water hardness affect Direct Blue dyeing?
A: Water hardness can significantly impact Direct Blue's performance. Hard water (containing Ca²⁺ and Mg²⁺ ions) may cause precipitation and uneven dyeing. We recommend using softened water (< 50 ppm hardness) or adding 1-2 g/L of sequestering agent (EDTA or NTA) to overcome hardness effects. In extreme cases, water hardness can reduce color yield by up to 15%.
Q: What are the effluent treatment requirements for Direct Blue wastewater?
A: Direct Blue wastewater should be treated using a combination of methods: coagulation-flocculation with alum or ferric salts (effective for 60-80% removal), followed by biological treatment. Activated carbon adsorption or advanced oxidation processes may be required for complete decolorization. Always check local regulations as discharge limits vary by region (typically < 50 mg/L COD and < 10 Pt-Co color units).