D Series
Dark series · deep shadesCOTFIX D Series is a four-shade reactive-dye range developed for deep shades on cellulosic fibres. Its published table lists Yellow D, Orange D, Red D and Blue D, each with solubility of 100 g/L at 30°C and a dischargeability entry of D. Rubbing, light and washing ratings vary by shade; this table does not establish a universal dosing saving compared with other dye classes.
Approval and conformance coverage varies by product and strength variant. Check product-specific evidence and request documents for your exact COTFIX grade; a series name is not a whole-range approval.
What shades and fastness data does COTFIX D Series publish?
COTFIX D Series is a four-shade reactive-dye range for deep shades on cellulosic fibres. The published table lists Yellow D, Orange D, Red D and Blue D, each with solubility of 100 g/L at 30°C and a dischargeability entry of D. Dry rubbing fastness is 4 to 5 for Yellow D and Blue D, and 4 for Orange D and Red D, while wet rubbing is 3 to 4 throughout. Light fastness reaches 4 to 5 for Yellow D, Red D and Blue D and 3 to 4 for Orange D. Nuchem publishes the values shade by shade so a buyer can compare deep-shade grades before enquiring.
| Dye | Shade 2% | Solubility gpl 30°C | Rubbing Fastness (Dry) | Rubbing Fastness (Wet) | Light Fastness 1/1 S/D | Washing Fastness (Shade) | Washing Fastness (Cotton) | Dischargeability |
|---|---|---|---|---|---|---|---|---|
| Cotfix Yellow D | 100 | 4-5 | 3-4 | 4-5 | 4-5 | 4 | D | |
| Cotfix Orange D | 100 | 4 | 3-4 | 3-4 | 3-4 | 3-4 | D | |
| Cotfix Red D | 100 | 4 | 3-4 | 4-5 | 4-5 | 4 | D | |
| Cotfix Blue D | 100 | 4-5 | 3-4 | 4-5 | 4-5 | 4 | D |
D — Dischargeable · PD — Partially dischargeable · ND — Not dischargeable. Understand the table terms.
How does COTFIX D Series compare with the other COTFIX ranges?
Nuchem positions COTFIX D for deep shades and COTFIX RR for very light and medium shades. In the published tables, all four D entries are marked dischargeable, while RR differs by shade: Yellow RR is partially dischargeable, Red RR is not dischargeable and Blue RR is dischargeable. All four D grades share a solubility of 100 g/L at 30°C, so deep-shade stock preparation is consistent across the range. COTFIX D is published as a dark series. A buyer should compare washing, light and rubbing values alongside the required shade depth rather than treat one series as universally better. Dischargeability and fastness entries should be read for each shade before a deep build is planned.
For one-tone build-up in warm dyeing and padding, compare RGB Series. Discuss the substrate, target shade depth and selected grade with Nuchem at the Sayakha and Vatva plants before choosing a process.
How is COTFIX D Series consistency held, lot after lot?
Fastness figures are only worth as much as the reproducibility behind the published values. Nuchem describes a three-point quality check, laboratory support and production-lot records across four QC laboratories. Public checks support the same picture: 24 COTFIX colourants appeared in the official GOTS approved-input database when checked on 29 September 2026, and OEKO-TEX ECO PASSPORT certificate 21.0.64039 covers 55 COTFIX products with a recorded validity date of 30 June 2027.
Nuchem describes a three-point check before delivery. Review the published quality-control approach and discuss the applicable test records for a selected COTFIX D grade.
QC labs at the Ahmedabad head office, Ludhiana regional office, and both the Sayakha and Vatva factories.
Nuchem maintains production-lot records for traceability. A separate Gateway check on 28 September 2026 verified 34 active COTFIX products at Control Union Level 3, and a buyer can request the applicable record for a selected grade and lot.
How does Nuchem treat wastewater from reactive-dye manufacture?
Nuchem's Sayakha plant at Bharuch runs as a 100% zero liquid discharge operation, so no liquid process effluent leaves the site. The published treatment train combines reverse osmosis with Mechanical Vapour Recompression (MVR) and an Agitated Thin Film Dryer (ATFD), rated at 53 kilolitres per day (KLD). Reverse osmosis recovers water ahead of evaporation, and the MVR and ATFD stage handles the concentrated residue. Condensate recovered through the train is recycled back into the manufacturing process, while the dried sludge goes to Gujarat Pollution Control Board (GPCB) approved Treatment, Storage and Disposal Facility (TSDF) sites.
The figures describe the Sayakha plant alone and must not be read across to the Vatva works at Ahmedabad without confirmation. Chemical-product approval of a COTFIX D grade is a separate check and does not certify a factory's water-treatment performance. Read the water-treatment explanation for the full published detail.
Need a sample or a shade match?
Share the shade, substrate and process to discuss grade selection, sample availability and product-specific documents.
Request a sample RGB Series — one-tone build-up