TRADE NAME:Acid Milling Yellow R,Vicoacid Yellow 42,Weak Acid Yellow C-R,Weak Acid Yellow R,Weak Acid Yellow MR,Acid Yellow N-CRS,Acid Yellow R,Acid Yellow MR,Aminyl Yellow F-MR,Apollo Nylon Fast Yellow M-R,Doracid Yellow R,Durapel Yellow R,Evron Yellow R,Dycroacid Milling Yellow MG,Dycroacid Yellow FG,Orco Milling Yellow RS,Rybacid Yelow 2R,Sandolan Milling Yellow N-SH,Selmacid Yellow N-2R,Suminol Milling Yellow MR
| Standard | Fiber | Soaping | Persperation Fastness | Oxygen bleaching | Light Fastness | |
| Fading | Stain | |||||
| AATCC | Wool | 4-5 | 4-5 | 4-5 | 1 | 4 |
| ISO | Wool | 4-5 | 5 | 4-5 | 4 | 4-5 |
Acid Yellow 42 shows highest affinity for protein fibers (wool, silk) and polyamide (nylon) because its anionic sulfonate groups bind electrostatically to cationic sites on these fibers under acidic conditions. This makes it ideal for apparel wool & silk dyeing and nylon hosiery or technical nylon parts. For confirmation of fiber compatibility, check small lab trials at production liquor ratios.
For even shades on wool: begin at pH ~4.0–4.5 (acetic acid or citric buffer), charge dye at low temperature, raise to 85–95°C slowly over 30–45 minutes, hold 30–45 minutes, then cool and rinse. Use leveling auxiliaries and 0.5–1.5 g/L of wetting agent for improved penetration; run small-scale trials to optimize liquor ratio and exhaustion for your substrate and depth.
Yes — Acid Yellow 42 mixes well with other acid dyes to produce varied yellows and greens. For reproducible mixes, create master recipes (grams per kg fiber at a fixed % owf), perform stepwise dosing in lab dyebaths, and adjust pH/temperature ramp to avoid differential exhaustion. Avoid mixing with dyes that require drastically different pH or fixative chemistry without re-testing.
Acid Yellow 42 can be removed efficiently by adsorption onto clays/bentonite or by coagulation/advanced oxidation depending on plant setup. Precipitation/coagulation followed by adsorption and biological treatment is common; consult your effluent specialist and SDS for safe handling and local discharge limits before selecting a treatment train.
Store in a cool, dry place in tightly sealed bags or drums, protected from moisture and sunlight. Avoid inhalation and skin contact—use appropriate PPE (gloves, goggles, respirator as needed). Keep SDS and COA on file; follow local regulations for transport and disposal.
1) Fix liquor ratio and replicate in pilot runs; 2) Use the same auxiliaries and water hardness control; 3) Maintain identical pH & temperature ramp profiles; 4) Produce & measure spectral data (ΔE) and record exhaustion/washfastness; 5) Adjust recipe as needed and document COA for each lot.
