Textile Dyeing Applications
Wool Sweater Dyeing (Batch Production)
Application Scenario: A textile factory producing mid-to-high-end wool sweaters requires a deep blue-black shade with good wash fastness (≥3) and no fiber damage.
Process Parameters:
- Substrate: 100% merino wool yarn (26S/2)
- Dye Dosage: 1.2% o.w.f (on weight of fiber)
- Dye Bath pH: 4.5 (adjusted with acetic acid)
- Dyeing Temperature: 90℃ (gradually raised from 40℃ at 2℃/min)
- Dyeing Time: 60 minutes (with 0.3% o.w.f anionic leveling agent added)
- Post-Treatment: Rinsed with 40℃ warm water, neutralized with sodium bicarbonate, and dried at 60℃
Performance Results:
- Color Uniformity: No streaks or uneven shading, blue-black shade consistent with Pantone 19-4062 TCX
- Fastness: Wash fastness (GB/T 3921-2008) Grade 4, light fastness (GB/T 8427-2019) Grade 3-4, rubbing fastness (GB/T 3920-2008) Grade 4 (dry)/Grade 3 (wet)
- Fiber Integrity: No shrinkage or brittleness, hand feel remains soft and elastic
Nylon-Cotton Blend Fabric Printing (Garment Industry)
Application Scenario: Printing on 70% nylon/30% cotton blend jackets for outdoor wear, requiring high color fastness and compatibility with screen printing processes.
Process Parameters:
- Dye Formulation: Acid Black 2 (1.5% by weight of paste) + Acid Orange Ⅱ (0.3% by weight of paste) to formulate Acid Black ATT shade
- Printing Paste: 5% sodium alginate thickener + 2% urea + 1% acetic acid (pH 5.0)
- Printing Process: 100-mesh screen printing, scraping twice for uniform coverage
- Fixation: Steaming at 105℃ for 20 minutes
- Washing: Cold water rinse → soaping (2g/L anionic detergent, 50℃) → warm water rinse → drying
Performance Results:
- Color Fastness: Meets outdoor wear requirements, wash fastness Grade 4, light fastness Grade 4, chlorine bleach fastness Grade 3
- Adhesion: No color fading or peeling after 50 rubbing cycles
- Compatibility: No adverse reactions between Acid Black 2 and cotton/nylon fibers, blend ratio does not affect coloring effect
Leather Coloring Application
Cowhide Shoe Upper Coloring
Application Scenario: Coloring full-grain cowhide shoe uppers to achieve a uniform blue-black finish with natural luster and resistance to flexing.
Process Parameters:
- Pre-Treatment: Leather degreasing → neutralization (pH 5.5) → retanning
- Dyeing Method: Drum dyeing
- Dye Dosage: 2.0% o.w.f (based on leather weight)
- Dye Bath: 80% liquor ratio, pH 5.0 (adjusted with formic acid), temperature 55℃
- Dyeing Time: 40 minutes (with 0.5% fatliquor added during the last 10 minutes)
- Post-Treatment: Fixing with 1% formic acid (pH 3.8) → drying → buffing → finishing
Performance Results:
- Appearance: Uniform color, natural grain retention, blue-black shade with subtle luster
- Durability: No color transfer after 20,000 flexing cycles (GB/T 22849-2014), wash fastness Grade 3-4
- Resistance: Tolerates daily sweat and minor water contact without fading
Paper Coloring Application
Packaging Paper Coloring (Food Contact Grade)
Application Scenario: Coloring inner lining paper for chocolate packaging, requiring food safety compliance and stable color under storage conditions.
Process Parameters:
- Paper Type: 80g/m² bleached kraft paper (food contact grade)
- Dye Addition: Added to pulp during beating process, dosage 0.8% based on oven-dry pulp weight
- Pulp pH: 6.0 (weakly acidic environment)
- Papermaking Process: Fourdrinier machine, forming speed 300m/min, drying temperature 110℃
Performance Results:
- Safety Compliance: Meets GB 4806.8-2016 (food contact paper and board materials) requirements, no heavy metals or harmful substances detected
- Color Stability: No yellowing or fading after 6 months of storage in 25℃/60% RH environment
- Physical Properties: Tensile strength and tear resistance unchanged compared to undyed paper, no dye migration to food simulant (95% ethanol)
Ink Manufacturing Application
Water-Based Ballpoint Pen Ink
Application Scenario: Formulating water-based ink for ballpoint pens, requiring smooth writing, quick drying, and no clogging.
Ink Formulation:
- Acid Black 2: 15% (colorant)
- Glycerol: 8% (humectant)
- Polyethylene glycol 400: 5% (lubricant)
- Carboxymethylcellulose sodium: 2% (thickener)
- Deionized water: 68% (solvent)
- pH Adjustment: 6.5 with triethanolamine
Performance Results:
- Writing Performance: Smooth ink flow, no skipping or clogging, line width consistent (0.5mm)
- Drying Time: ≤30 seconds on common printing paper
- Stability: No sedimentation or stratification after 6 months of storage at room temperature
- Fastness: Writing remains legible after paper is wetted and dried, light fastness Grade 3
Cosmetic Coloring Application
Eyebrow Pencil Pigment (Non-Injectable)
Application Scenario: Coloring solid eyebrow pencils, requiring skin safety, non-irritation, and resistance to sweat and water.
Formulation:
- Acid Black 2: 10% (pigment, micronized to 5μm particle size)
- Beeswax: 30% (binder)
- Castor oil: 25% (emollient)
- Carnauba wax: 15% (hardener)
- Vitamin E: 0.5% (antioxidant)
- Other additives: 19.5% (preservatives, stabilizers)
Performance Results:
- Safety: Meets GB 7916-2013 (Hygienic Standards for Cosmetics), no skin irritation in patch tests (24 hours)
- Durability: Resists sweat and water for 8 hours without smudging
- Stability: No color change or hardening after 12 months of storage at 25℃/50% RH
Key Notes for Application Cases
- All cases use high-quality Acid Black 2 (purity ≥95%, HPLC-verified) to ensure performance consistency.
- Substrate pre-treatment (e.g., degreasing, neutralization) is critical for optimal dye adsorption and fastness.
- Metal ion control (using chelating agents such as EDTA) is recommended in dye baths to avoid color distortion.
- For food contact or cosmetic applications, ensure the product complies with relevant safety standards (e.g., FDA 21 CFR Part 73 for food contact, EU Regulation 1223/2009 for cosmetics).
