Auxiliary Selection and Application Guidelines

Proper auxiliary selection and application requires understanding fiber-auxiliary interactions, process conditions, compatibility, and optimization to achieve desired results cost-effectively while minimizing environmental impact and quality defects. Selection criteria include fiber type compatibility, process type (exhaust vs. continuous, temperature 20-130°C, pH 2-13), equipment type, performance requirements, cost constraints ($0.05-0.50/kg fabric typical), and environmental regulations. Dosage optimization identifies minimum effective concentration reducing costs 10-30% vs. standard recommendations through trials testing 50-150% of recommended dose. Application sequence critical in multi-auxiliary processes with exhaust dyeing sequence: wetting agent, sequestrant, leveling agent, dye, pH adjustment, post-dyeing auxiliaries, and final treatments. Compatibility testing prevents precipitation and phase separation with common incompatibilities including anionic-cationic mixtures, high-pH sensitive compounds, and oxidizer-reducer reactions. Liquor ratio 1:5 to 1:30 affecting auxiliary concentration with conversion between g/L and % owf via formula: g/L = (% owf × fabric weight kg × 10) / liquor volume L. Quality control includes incoming inspection (±5-10% tolerance), functional testing, and proper storage (5-40°C, sealed containers, FIFO rotation). Defect diagnosis addresses unlevel dyeing, streaks, foam overflow, stiff hand, odor, color change, and precipitation through systematic troubleshooting. Cost tracking monitors auxiliary costs per kg fabric: pretreatment $0.10-0.30, dyeing $0.15-0.50, finishing $0.20-0.80, printing $0.50-2.00, total $0.95-3.60 with optimization via dosage reduction, supplier consolidation, substitution, and process improvement. Environmental management prioritizes biodegradable auxiliaries (greater than 60%), minimizes consumption, implements wastewater treatment (70-95% removal), and develops closed-loop systems (50-90% discharge reduction).