Acid Red 357 is a water-soluble acid dye formulated to produce bright red to red-violet shades on protein and polyamide fibers. It is primarily used for dyeing wool, silk and nylon in both lab and production dyehouses where consistent shade, good leveling and predictable performance are required. The dye is compatible with common acid-dye auxiliaries and can be applied in exhaust, continuous and pad-batch processes after suitability testing.
TRADE NAME:Acid Scarlet ML,Neutral red ML
Standard | Fiber | Soaping | Persperation Fastness | Oxygen bleaching | Light | |
Fading | Stain | |||||
ISO | Wool | 5 | 5 | 4-5 | 6-7 | |
Testing method | fiber | Alkali resistant | Carbonization | steaming wool | Alkaline fluff | seawater | soaping | Perspiration discoloration | Light fastness | |||
discoloration | stain | discoloration | stain | discoloration | stain | |||||||
ISO | wool | 3~4 | 4~5 | 4~5 | 4~5 | 4~5 | 4~5 | 4~5 | 5 | 5 | 4~5 | 6~7 |
Acid Red 357 is optimized for protein fibers (wool, silk) and synthetic polyamide fibers such as nylon. It is not effective on untreated cellulose fibers (cotton) without a mordant or carrier system designed for acid dyes.
For most wool and silk applications aim for a mildly acidic bath (pH 2.5–4.5). Follow your fiber supplier’s recommended temperature profile—lab trials often start with a gentle warm-up to 60–70°C and then raise as needed for leveling. Maintain a consistent liquor ratio between lab and production runs and keep pH/auxiliary dosing strictly controlled for reproducibility.
Yes — it can be blended with other acid dyes to tune hue and depth, but always run compatibility and migration tests. For continuous or pad-batch processes, adapt the fixation and after-treatments to the process and re-test recipes at production speed to avoid surprises.
Acid dyes typically show moderate to good wet fastness. To enhance performance consider: (1) optimised dyeing recipe and thorough rinsing, (2) appropriate use of fixing agents or leveling assistants designed for acid dyes, and (3) post-dyeing treatments recommended for the specific fiber (e.g., mild after-baths). Note that light fastness is dye-dependent; evaluate with accelerated light-fastness tests for outdoor or high-exposure uses.
Follow the product SDS. Avoid inhalation of powder and contact with skin/eyes — use gloves, eye protection and dust control when handling. Collect and treat rinse effluent in accordance with local regulations; avoid discharging concentrated dyebaths directly to sewer without permitted treatment.
Document the lab recipe (liquor ratio, pH, temperature rise rate, auxiliaries) and reproduce the same bath dynamics in production. Use spectral shade matching, conduct pilot runs at intermediate volumes, and adjust for liquor ratio and machine specific factors. Keep records of dye lot and auxiliaries for traceability.
