Acid Red 1 is a water-soluble azo acid dye supplied as a red to dark-red crystalline powder. Predominantly used for protein fibers (wool, silk) and polyamide (nylon), it offers reliable levelness and good compatibility with standard acid dyeing and printing processes.
Standard | Fiber | Soaping | Persperation Fastness | Oxygen bleaching | Light | |
Fading | Stain | |||||
AATCC | Wool | 2 | 2 | 2 | 1 | 4 |
ISO | Wool | 3 | 5 | 4-5 | 1 | |
Leveling(grade) | Displacement | Whitening | Solubility(g/L) | metal iron effect(grade) | ||
copper | iron | chromium | ||||
5 | A | well | 100(90℃) | 3 | 3~4B | — |
Test Methods | fiber | Alkali resistance | Carbonization | Chlorination discoloration | Oxygen bleaching | Alkali fluff | Acid fluff | potting | soaping | Perspiration | Sun exposure | ||||
discolor | Staining | discolor | Staining | discolor | Staining | discolor | Staining | ||||||||
AATCC | wool | 3~4 | 4 | 1 | 1 | 1~2 | 1~2 | — | — | — | — | 2 | 2 | 2 | 4 |
ISO | wool | 4 | 3 | 2 | 1 | 1 | 2 | 2 | 1 | 2 | 2 | 3 | 5 | 4~5 | 5 |
Mainly used in strong acid medium in the wool dyeing and the piece dyed wool. Can be directly in the wool fabrics, polyamide fiber and fabric silk printing. Also can be used for leather dyeing, also can be used in the manufacture of color amylum, cosmetics, paper, soap and timber colorants, is used to make the ink. The Barium salt can be used in organic pigments.
For reduced dust and better dosing consistency consider granulated or wet-paste grades. Pre-disperse in dye liquor for printing applications. Use local extraction and PPE when handling powders.
Run small-lab trials (1% owf) and record K/S or spectrophotometric values; keep master records for each lot to control ΔE in production runs.
Store in a cool, dry place. Protect from moisture and strong oxidizing agents. Keep containers tightly closed.
Acid Red 1 is optimized for protein fibers (wool, silk) and polyamide (nylon) using an acid dyeing bath. It performs well in exhaust dyeing and acid printing where controlled pH yields even levelness. It is not recommended for unmodified cellulose (cotton) without special mordanting or crosslinking.
Shade and hue respond to bath pH and trace metal ions: stronger acidity preserves the red tone, while alkaline shifts can darken or brown the shade; copper or iron traces can shift the hue toward bluish/darker tones. Use chelators or controlled bath chemistry to maintain target shade.
Provide Acid Red 1 as granules or wet paste for lower dust. Pre-disperse in the dye liquor for printing; keep transfer lines flushed after dosing to prevent clogging. Use local extraction and dust masks during bagging operations.
Perform a 1% owf lab batch on the actual substrate using your standard acid bath recipe. Measure K/S or spectrophotometric λmax and record CIELAB coordinates. Maintain master lab records for each dye lot and compare ΔE to your quality tolerances.
Grades are sold by dye content (e.g., 60–80% assay) and insoluble matter. Higher dye content increases tinctorial strength and reduces required solids; low insoluble matter (<0.5%) helps prevent specking and improves clarity in printing.
Regulatory acceptance varies by jurisdiction and product category. For finished consumer or cosmetic applications, verify local approvals and use certified colorant forms if required. For industrial textile uses, follow the SDS and wastewater guidance.
