Direct Blue 108

Direct Blue 108 is a bright direct (water-soluble) textile dye of the oxazine/triphenyl class commonly sold as a blue powder. It is mainly used for dyeing cotton, viscose (rayon), silk and blended fabrics and is marketed under trade names such as Direct Fast Blue FFRL / Remastral Blue FFRL.

TRADE NAME:Direct Blue FFRL,Direct Fast Blue FFRL,Direct Fast Blue FFRL,Direct Light Blue FFRL,Leadirect Rasin Fast Blue FFRL,Orcolitefast Blue FFRL

Key features

• Appearance: bright blue powder / granular form suitable for bulk handling.
• Primary fiber compatibility: cotton, viscose (rayon), silk and their blends.
• Water solubility: limited/poor in some grades — usually supplied as a powder with dispersing characteristics; requires proper wetting and leveling aids for even exhaustion.
• Leveling & exhaustion: generally good leveling on cellulosic fibers when used with salt and alkali adjustments; optimized recipes improve evenness and depth.
• Fastness profile (typical industry ranges): light fastness often reported high (e.g., 5–7 scale depending on test), wash fastness moderate (commonly 3–4), rubbing fastness dry 4–5 / wet ~3.
• Common formats: powder for exhaust dyeing; sometimes supplied as liquid concentrates for continuous processes.
• Typical applications: garment and home-textile dyeing (not generally recommended for printing inks); also used in paper and leather dyeing in some formulations.

Direct Blue 108 Application:

Used for cotton, viscose, silk and their blended fabric dyeing, general is not used for printing. Usually used for washing the less number of flocking fabric.

Technical Specifications

• ‍CAS NO: 1324-58-9
• CI.NO: 51320
• Molecular Formula:C34H19Cl2N4Na3O11S3
• Molecular Weight: 895.61
• Shade: bright blue powder‍

FAQ

How can I improve wash fastness of Direct Blue 108 on cotton?

Use a post-dye cationic fixing treatment (commercial fixing resin or cationic starch), rinse well, and consider mild after-soaping; lab trials will identify the optimal fixer and dosage.

Is Direct Blue 108 suitable for reactive dyeing or printing?

No — it’s a substantive (direct) dye formulated for exhaust dyeing. It’s generally not recommended for reactive chemistry or pigment printing pastes.

What starting shade and recipe should I try in the lab?

Begin with 0.5–2.0% owf (optical weight of fabric) in an exhaust bath, temperature and salt/alkaline regime per your standard direct-dye procedure; always run small-scale trials.

Which auxiliaries are compatible or should be avoided?

Compatible: standard leveling agents, wetting agents and mild salts. Avoid strong reducing agents, very strong acids/alkalis and harsh surfactants that damage substantive binding.