Trade Name: DIRECT BLACK · CI Number: Direct Black 80
Direct Black 80 is a polyazo direct dye for cotton, viscose, linen, jute, and paper — prized for its neutral jet-black shade with no blue or brown undertone. This distinguishes it from Direct Black 22, which carries a perceptible blue cast at medium depths. The dye applies directly from a neutral salt bath without an alkali step or mordant, giving one of the simplest black dyeing processes available for cellulosic substrates. Yobai Industries supplies this grade with batch-wise quality testing for consistent colour strength and build.
Exhaustion runs at 90–100°C with sodium chloride or sodium sulphate (20–30 g/L), added in two or three portions over the first 20–30 minutes to control strike and levelness. No alkali is needed — the physical bond forms without covalent linkage, keeping the process simple and pH-tolerant. After dyeing, a cationic fixative at 40°C (1–2% owf, 20 minutes, pH 4–5) raises wash fastness from 3–4 to 4, bringing it into range for garment and domestic-wash applications. Light fastness of 3–4 makes it best suited to indoor textiles, home furnishings, and paper products not exposed to prolonged direct sunlight.
Specifications are indicative. Contact us for a batch-specific TDS before placing a bulk order.
| Parameter | Value |
|---|---|
| Product Name | Direct Black 80 |
| Trade Name | DIRECT BLACK |
| CI Number | Direct Black 80 |
| CAS Number | Available on request |
| Colour | Black |
| Appearance | Black Powder |
| Ionic Character | Anionic |
| Solubility | Soluble in hot water. |
| Application pH | Neutral (pH 7) |
| Application Temp. | 90–100°C |
| Required Auxiliaries | Sodium chloride or sodium sulphate (20–30 g/L); optional cationic after-treatment for improved wash fastness |
| Wash Fastness | 3–4 |
| Light Fastness | 3–4 |
| Packaging | 1 kg · 5 kg · 10 kg · 25 kg · 50 kg · Custom packaging available |
| Shelf Life | 5 years from manufacture (cool, dry storage) |
| Manufacturer | Yobai Industries, Sayakha, Gujarat, India |
| GSTIN | GST Registered |
Need a full TDS, COA, or MSDS? Request it here or WhatsApp us directly.
Being a polyazo grade, Direct Black 80 is a larger molecule than disazo direct blacks. It dissolves more slowly in cool water and benefits from pre-dissolution at 60–70°C. The physical bond with cellulose is what makes direct dyes simpler to apply than reactive dyes — no alkali activation step — but also why wash fastness is inherently lower and why cationic fixative after-treatment is standard practice for garment fabrics.
| Property | Value / Rating |
|---|---|
| Physical Form | Fine black powder |
| Bulk Density | Approx. 0.4–0.6 g/cm³ |
| Solubility in Water | Dissolves in hot water at 60–70°C; limited solubility at room temperature |
| Dye Bath Stability | Stable at pH 6–10; avoid prolonged exposure below pH 5 |
| Wash Fastness — Untreated (ISO 105-C06) | 3–4 |
| Wash Fastness — With Cationic Fixative | 4 |
| Light Fastness (ISO 105-B02) | 3–4 |
| Rubbing Fastness — Dry | 3–4 |
| Rubbing Fastness — Wet | 3 |
| Perspiration Fastness (Acid) | 3–4 |
| Perspiration Fastness (Alkaline) | 3 |
Fastness ratings on the standard 1–5 scale (5 = best). Cationic fixative after-treatment is strongly recommended for cotton garment and knitwear applications. Batch-specific COA with fastness data available on request from technical@yobaiindustries.in.
Direct Black 80 produces a neutral jet-black at all concentration levels, without the blue cast seen in Direct Black 22 at low-to-medium depths. Shade depth is controlled primarily by dye% owf and salt concentration.
Shade appearance is consistent across the depth range — no undertone shift between light and heavy builds is the key differentiator of DB80 vs DB22. Request a lab dip at your target depth before bulk production.
All packs are sealed in multi-layer moisture-proof bags. Custom packaging and private labelling are available for bulk buyers and trading companies.
All shipments include batch-specific COA, MSDS, and GST invoice. Export packing in UN-certified drums available on request.
The standard exhaust dyeing process for Direct Black 80 on cotton or viscose runs in four stages: preparation, dye addition, exhaustion at boil, and optional cationic after-treatment. Salt is staged across two additions to control strike rate and prevent unlevel take-up. No alkali is used at any stage — the dye forms its physical bond through temperature and salt concentration alone.
| Stage | Action | Conditions |
|---|---|---|
| 1. Bath setup | Fill machine; add wetting agent (0.5–1 g/L); check pH 7–8 | 40°C, LR 1:10–1:15 |
| 2. Dye addition | Pre-dissolve dye in hot water (60–70°C); add slowly to running bath | 40–50°C |
| 3. Salt — 1st stage | Add 50% of total NaCl or Na₂SO₄ dose | 50°C, run 10 min |
| 4. Ramp temperature | Raise to 90–100°C at 2–3°C/min | Over 20–25 min |
| 5. Salt — 2nd stage | Add remaining 50% salt once boil is reached | 90–100°C |
| 6. Exhaustion hold | Run at boil until bath clears; check with trichromatic reading if available | 45–60 min, pH 7–8 |
| 7. Rinse | Drop bath; rinse warm (60°C) then cold — no soaping required | No alkali wash-off |
| 8. Cationic fixative | Fresh bath: 1–2% owf fixative, acidify to pH 4–5 with acetic acid | 40°C, 20 min |
| 9. Final rinse & dry | Cold rinse; hydroextract; frame or tumble dry | Standard finish |
Reference dosages for mercerised cotton at LR 1:10. Confirm with a lab dip before bulk production — substrate preparation, water quality, and machine type all affect final depth.
| Shade Depth | Dye % owf | NaCl / Na₂SO₄ (g/L) | Temp. | Hold Time |
|---|---|---|---|---|
| Pale Black | 0.5–1.0% | 15–20 g/L | 90°C | 30–40 min |
| Medium Black | 1.5–2.5% | 20–25 g/L | 95°C | 45 min |
| Full Black | 3.0–4.0% | 25–30 g/L | 100°C | 50–60 min |
| Jet / Deep Black | 4.5–6.0% | 30 g/L | 100°C | 60 min |
Paper dyeing: Add dye to pulp furnish at 0.2–1.5% on dry fibre weight. No separate salt is needed in the pulp furnish — cellulose affinity drives take-up without electrolyte assistance.
Most problems with Direct Black 80 trace back to dissolution, salt staging, or temperature management. The following covers the issues dyehouses encounter most often.
Usually caused by adding all the salt at once at the start of the bath, which drives rapid, uneven dye strike onto the fabric before temperature has equalised across the load. Correction: Stage salt addition — 50% at 50°C and the remaining 50% at boil. Ensure fabric is thoroughly pre-wetted before entering the bath. For winch machines with uneven fabric movement, reduce the first-stage salt to 30% and spread the remainder across three additions.
Occurs when the bath temperature does not consistently reach 95–100°C, or when the liquor ratio is high and salt concentration is insufficient to drive exhaustion. Correction: Confirm bath temperature at the fabric — not just at the heat source. Increase salt to 30 g/L for deep shades. Check dye dissolution: undissolved granules floating in the bath lead to dye wastage and patchy build. Always dissolve at 60–70°C, not in cold water.
Direct dyes without after-treatment bleed noticeably in warm-water domestic washes. This is inherent to the dye class — not a quality defect. Correction: Apply cationic fixative at 1–2% owf, 40°C for 20 minutes at pH 4–5. Use a fresh fixative bath for each lot — exhausted baths give significantly weaker improvement and can leave uneven fixing across the load. This single step improves wash fastness from 3–4 to 4.
Direct Black 80 is a high-MW polyazo dye and dissolves more slowly than smaller azo grades — it forms a gel-like mass in cool water rather than dissolving cleanly. Correction: Pre-dissolve in hot water (60–70°C) with continuous stirring for at least 5 minutes. If any particles remain, strain through a fine mesh before addition. Do not add powder directly to the machine bath — this creates localised high-concentration spots that cause dark streaks on fabric.
Store in a cool, dry place below 30°C, away from direct sunlight and moisture. Keep containers sealed between uses. Avoid storage near strong acids, oxidising agents, or bleaching compounds.
This dye is used by manufacturers across the following industries. Contact us with your specific application for a grade recommendation.
Yobai Industries carries the following grades in this dye family. Click any grade to view specifications, or view the full catalogue →
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MOQ 10 kg · Samples in 24 hours · Bulk in 7–15 days · Export worldwide · GST invoice with every order.