Applications of Vat Black 25 in Industrial Manufacturing

Vat Black 25 is a high-performance vat dye widely used in the manufacturing of deep black coloration for industrial textile, leather, paper, and specialty fiber sectors. As a primary production manufacturer, we support end-users seeking consistent quality, regulatory compliance, and efficient process integration across the major application pathways for this raw material.

1. Cellulosic Textile Dyeing

Large-scale textile mills in denim, workwear, and technical cotton segments utilize Vat Black 25 for its stability under severe washing, high light-fastness, and deep penetration. The dye is reduced in a high-alkaline leuco state, then impregnated into cellulosic fibers, followed by oxidation and fixation. Strict process controls enable batch and continuous dyeing to meet specifications for reactive durability, hue strength, and fastness properties, essential for apparel, uniforms, and utility fabrics.

Industry compliance standards

• OEKO-TEX Standard 100
• ZDHC MRSL V3.1
• ISO 105-C06 (Wash Fastness)
• REACH Regulation (EC) No 1907/2006

Typical usage ratio

• 1.0% – 4.0% owf (on weight of fiber), adjusted for required shade depth, liquor ratio, and cotton blend.

Downstream process integration

• Introduced during dye bath preparation with sodium hydrosulphite and caustic soda reduction.
• Fiber impregnation in jet, jigger, or continuous pad-batch dyeing lines.
• Chemical oxidation and intensive rinsing to fix shade.

Final product types

• Denim garments
• Industrial uniforms and workwear
• Canvas and twill fabrics
• Protective outerwear textiles

2. Viscose and Modal Fiber Mass Coloration

Synthetic fiber plants apply Vat Black 25 within dope-dye processes for viscose and modal manufacture. Direct dispersion of the dye into the spinning dope ensures color uniformity, while temperature and pH control are critical for full dye migration and fiber integrity. This process is essential for furnishing spinners with non-fading, deep black regenerated cellulose fibers for knitting and weaving applications.

Industry compliance standards

• ISO 9001:2015 (Quality management in production)
• ZDHC MRSL V3.1
• GB/T 2912.1 (Azo dye content testing)
• REACH Annex XVII restrictions

Typical usage ratio

• 0.7% – 2.0% by mass, calibrated by targeted L* value and required fiber cross-section darkness.

Downstream process integration

• Added to the spinning dope immediately prior to wet spinning phase in viscose or modal lines.
• Controlled mixing, filtration, and coagulant addition to achieve even color within continuous tow.

Final product types

• Dope-dyed viscose filament and staple fibers
• Modal yarns for fashion and sportswear
• Fabrics for healthcare and hygiene applications

3. Black Paper and Packaging Board Production

Paper mills producing black specialty boards and decorative paper employ Vat Black 25 for bulk pulp coloration due to its high lightfastness and non-bleeding nature. The dye is incorporated during the wet-end to ensure deep, long-lasting color after drying and finishing, supporting the requirements for premium packaging and luxury wrapping grades where uniformity and environmental safety are critical.

Industry compliance standards

• EN 646 (Color fastness to bleeding in paper and board)
• FSC controlled wood sourcing requirements
• CEPI Food Contact Guidelines (for indirect packaging)
• REACH Regulation (EC) No 1907/2006

Typical usage ratio

• 0.5 – 1.5 kg per ton of dry pulp, adaptable based on furnish type, grammage, and desired opacity.

Downstream process integration

• Metered addition to wet-end chest during pulping, preceding sheet former.
• Refining, pressing, and sizing stages to lock in shade depth.

Final product types

• Black folding carton grades
• Specialty graphic and presentation papers
• Decorative papers for laminates and boards

4. Leather Garment Drum Dyeing

Leather tanneries use Vat Black 25 in the wet-end drum dyeing phase to process full-grain, split, or corrected-grain cattle hides. This method achieves uniform, deep black shades with exceptional perspiration and rubbing resistance. Thorough pH and float control facilitate even uptake and fixation during the fatliquoring and retanning stages, enabling consistent results on both garment and upholstery substrates.

Industry compliance standards

• EN ISO 11640 (Rub Fastness)
• LWG Gold Rated Environmental Audits
• REACH Restriction Annex XVII (Aryl amines)
• AFIRM RSL chemical compliance

Typical usage ratio

• 0.3% – 2.5% owf, with adjustment for hide origin, thickness, and product type requirements.

Downstream process integration

• Dissolved in hot water bath for even dispersion in drum during wet-end.
• Applied post-neutralization before the retanning and softening steps.

Final product types

• High-fashion leather garments
• Automotive upholstery leathers
• Footwear lining leather
• Luxury bag and accessory leathers

5. Technical Yarn and Cord Manufacturing

Manufacturers of industrial yarns, tire cords, and conveyor belts employ Vat Black 25 for the dyeing of high-modulus cellulosic and blended technical fibers. The dye provides stable shade performance under thermal and mechanical stress encountered in downstream conversion and end use. Process optimization is required to ensure color uniformity and strength retention during high-speed finishing and treatment.

Industry compliance standards

• ISO 1833 (Textile fiber blend testing)
• ISO 105-B02 (Light fastness of textiles)
• REACH compliance for export
• Customer-mandated QC certification of color durability

Typical usage ratio

• 1.0% – 2.5% owf, set according to blend, denier, and final application environment.

Downstream process integration

• Batch or continuous dyeing onto bobbins, cakes, or warp beams prior to weaving or knitting lines.
• Integrated within sizing or finishing baths for added durability.

Final product types

• Tire and industrial reinforcing cords
• Conveyor belt fabrics
• Technical webbing and harness straps
• Safety workwear yarns