Cotton AFIS Single-Fibre Analysis
topic
AFIS (Advanced Fibre Information System, Trützschler AFIS Pro 2) measures 3,000–5,000 individual cotton fibres per test through an electro-optical sensor detecting fibre length, diameter, maturity, nep count, trash, and seed coat fragments — providing fibre length and maturity distributions impossible to obtain from HVI bundle measurements. Key parameters: nep count (total neps per gram, mechanical nep <200 µm and seed coat nep separately counted, optimum total <200/g for ring spinning); short fibre content SFCn (% fibres shorter than 12.7 mm by number, optimum <10% — SFCn correlation with ring yarn thin places R² = 0.85 per USTER research); Lw (weight-biased mean length, mm, correlation with HVI UHML R² = 0.92); maturity ratio MR (cross-sectional maturity by single-fibre near-infrared cell, MR < 0.80 indicates immature fibre causing nep formation and dyeing problems). AFIS test time: 3–5 minutes per sample providing 25+ parameters versus HVI 60 seconds for 7 parameters — AFIS is the spinning mill process control instrument while HVI is the commercial classing instrument. Correlation between AFIS SFCn and carding parameters: SFCn 8% → card flat speed 300 mm/min, SFCn 14% → flat speed 450 mm/min to maintain nep count control below 80/g in delivered sliver. Comber noil prediction: AFIS SFCn(w) × 1.3 ≈ optimal comber noil% for ring-spun fine count yarn production, enabling noil setting before production trials.
Role
AFIS single-fibre analysis is the process intelligence instrument for cotton spinning mills, providing the short fibre, nep, and maturity distribution data that enables predictive process parameter setting for carding, combing, and ring spinning — transforming reactive quality management into proactive process control that prevents the production of off-quality yarn.