Acid Yellow 49 is an anionic acid dye widely used for dyeing protein and polyamide fibers such as wool, silk and nylon. It gives a clear, bright yellow shade with good leveling and predictable shade reproducibility in industrial and lab dyeing processes. Formulated for easy solubility and stable performance in acidic dyebaths, Acid Yellow 49 is suitable for textile mills, garment finishing, and specialty applications where a vibrant yellow and consistent fastness profile are required.
TRADE NAME:Acid Yellow GR,Acid Yellow 3 GK,Aminyl Yellow E-3GL,Apollo Nylon Fast Yellow GR,Egacid Yellow GR;Kiwacid Yellow 4G-E,Kayanol Yellow NFG,Nylanthrene Brilliant Yellow,Nylosan Yellow E-4G,Orco Nylosol Yellow 9GL,Rifa Acid Fast Yellow E-FGL,Sellanyl Yellow E-GL,Selmacid Yellow E-GL,Teconyl Yellow L-GL,Telon Light Yellow FG,Telon Yellow K-FGL,Weak acid Yellow GR,Weak acid Yellow NFC,Weak acid Yellow E-4G
Standard | Fiber | Soaping | Persperation Fastness | Oxygen bleaching | Light | |
Fading | Stain | |||||
ISO | Wool | 2-3 | 3 | 3 | 3 | 5-6 |
Test Methods | fiber | Alkali resistance | Carbonization | potting | Oxygen bleaching | Alkali fluff | Acid fluff color change | seawater | soaping | Perspiration | Sun exposure | |||
discolor | Staining | discolor | Staining | discolor | Staining | |||||||||
ISO | wool | 4 | 4 | 4~5 | 3 | 1~2 | 2~3 | 3~4 | 3 | 2~3 | 2~3 | 3 | 3 | 5~6 |
Fixing situation | soaping(60℃) | Alkali perspiration | Flooding | Sun exposure | ||||||
discolor | Nylon stain | Cotton stain | discolor | Nylon stain | Cotton stain | discolor | Nylon stain | Cotton stain | ||
Unfixed | 3~4 | 4 | 5 | 5 | 4 | 4~5 | 5 | 4~5 | 5 | 5~6 |
Fixing | 4~5 | 4~5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | |
For most wool and nylon applications with Acid Yellow 49, target a mildly acidic bath. Start trials at pH 4.0–4.8 (buffered with sodium acetate / acetic acid or equivalent). This range balances fiber protonation (for ionic bonding) with minimized fiber damage; some neutral/milling acid variants may perform up to pH 5–6, so verify on lab swatches for leveling and fastness. (Start small and record K/S and wash/light fastness per sample.)
A common industrial approach is to begin at ~50°C with the goods in the bath, then raise gradually to 85–98°C and hold until exhaustion or the manufacturer’s recommended hold time (often 30–90 minutes depending on depth of shade and liquor ratio). Avoid thermal shock on protein fibers; gradual heating improves levelness. Always run a pilot trial with your equipment and liquor ratio.
Deeper shades (higher % owf) generally show reduced apparent wash and light fastness compared with pale shades because more unfixed dye or dye aggregation can remain; leveling agents and appropriate post-dye soaping can improve results. We recommend fixed and washed swatches and ISO standard fastness tests at each commercial shade to set QA limits.
Acid Yellow 49 is a single-azo acid dye (not a metal-complex dye). It can be used in recipes alongside other leveling acid or milling dyes, but metal complex dyes have different exhaustion and fixation kinetics — blending requires compatibility trials to avoid differential migration or blotching. Use sequencing (apply metal-complex and milling dyes per their recommended pH/temperature windows) when necessary.
A Handle the powder in local exhaust or with dust controls to reduce inhalation. Use standard PPE: gloves, eye protection, and a dust mask/respirator if dust is present. Follow the supplier MSDS for eye irritation and other hazard statements (GHS data may include H319) and establish eyewash and spill procedures in the dyehouse.
Acid Yellow 49 is amenable to advanced treatment methods; the literature documents effective decolorization by electrochemical oxidation and advanced oxidation processes. For practical wastewater management, use primary color removal (coagulation/adsorption) followed by oxidative or biological polishing suited to your effluent characteristics; pilot tests are essential. Coordinate with your effluent treatment provider for regulatory compliance.
