ME Bifunctional Series
VS-MCT bifunctionalCOTFIX ME Series is a seven-shade reactive-dye range for lower-temperature processing of cellulosic fibres. Its bifunctional system combines vinyl sulphone and monochlorotriazine reactive groups, and the published applications include exhaust, cold pad batch and continuous dyeing. The table reports solubility and fastness shade by shade; lower-temperature use does not specify a universal bath temperature, dosing level or process recipe.
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 ME Series publish?
COTFIX ME Series is a seven-shade VS-MCT bifunctional reactive-dye range for lower-temperature processing of cellulosic fibres. The published table lists Yellow ME4GL, Yellow MERL, Orange ME2RL, Red ME4BL, Red BS, Brilliant Blue FNG and Sky Blue G. Solubility is 100 g/L at 30°C for five grades, 65 g/L for Orange ME2RL and 60 g/L for Red BS. Light fastness reaches 6 for the two blues and 4 or 5 elsewhere. Dischargeability is mixed: Yellow ME4GL is dischargeable, Yellow MERL is partially dischargeable, and the remaining five grades are not dischargeable. Nuchem publishes the values shade by shade so a buyer can compare lower-temperature 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 ME4GL 200% | 100 | 4-5 | 3-4 | 5 | 4-5 | 4 | D | |
| Cotfix Yellow MERL 200% | 100 | 4-5 | 3-4 | 5 | 4-5 | 4 | PD | |
| Cotfix Orange ME2RL 200% | 65 | 4 | 3-4 | 4 | 4-5 | 4 | ND | |
| Cotfix Red ME4BL 200% | 100 | 4 | 3-4 | 4 | 4 | 3 | ND | |
| Cotfix Red BS | 60 | 4 | 3-4 | 4 | 4 | 4 | ND | |
| Cotfix Brilliant Blue FNG | 100 | 4-5 | 3-4 | 6 | 4-5 | 4-5 | ND | |
| Cotfix Sky Blue G | 100 | 4-5 | 3-4 | 6 | 4-5 | 4 | ND |
D — Dischargeable · PD — Partially dischargeable · ND — Not dischargeable. Understand the table terms.
What makes COTFIX ME Series a bifunctional reactive range?
COTFIX ME Series is a lower-temperature, high-exhaustion reactive range built on VS-MCT bifunctional reactive groups. The VS part is vinyl sulphone and the MCT part is monochlorotriazine, so two reactive systems can bond the dye to cellulose. The published applications are exhaust, cold pad batch and continuous dyeing. Nuchem lists ME with a broad shade gamut, good build-up for deeper shades, good wash fastness and reproducibility, and mixability with VS dyes for vibrant shades. The bifunctional chemistry is a selection guide rather than a fixed recipe, so the substrate and grade should be discussed before a process is chosen.
- Broad shade gamut
- Good build-up for deeper shades
- Good wash fastness & reproducibility
- Mixes with VS dyes for vibrant shades
Compare the VS range for broader dyeing and printing uses, or HE Series for its published higher-temperature exhaust application at 80–95°C. Confirm the exact ME grade and process conditions with Nuchem before mixing dyes.
How is COTFIX ME 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 at Ahmedabad, Ludhiana, Sayakha and Vatva. For a bifunctional ME grade, lot-to-lot reproducibility matters, so a buyer should confirm the test record for the chosen grade. Public checks agree: the 28 September 2026 Gateway review verified 34 active COTFIX products at Control Union Level 3, and OEKO-TEX ECO PASSPORT certificate 21.0.64039 covers 55 COTFIX products.
Nuchem describes a three-point check before delivery. Review the published quality-control approach and discuss the applicable test records for a selected COTFIX ME 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.
Does a COTFIX ME approval cover Nuchem's factory water treatment?
A chemical-product approval of a COTFIX ME grade is a separate check and does not certify a factory's water-treatment performance. Published site evidence describes the Sayakha plant at Bharuch, which runs at 100% zero liquid discharge, so no liquid process effluent leaves the site. The treatment train uses reverse osmosis, Mechanical Vapour Recompression (MVR) and an Agitated Thin Film Dryer (ATFD), rated at 53 kilolitres per day (KLD).
Condensate recovered through the train is recycled into the ME manufacturing process, and dried sludge is routed to Gujarat Pollution Control Board (GPCB) approved Treatment, Storage and Disposal Facility (TSDF) sites. The published account and the pictured equipment describe the Sayakha train. The 100% zero liquid discharge status and the 53 KLD rating apply to Sayakha and should not be read across to Vatva (Ahmedabad) without confirmation. Read the water-treatment explanation for the full 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 VS Series — vinyl sulphone