Filament and Textured Yarn Testing

Filament and textured yarn testing characterises the specific properties of continuous multifilament, monofilament, draw-textured (DTY), air-textured (ATY), and partially oriented (POY) yarns that differ fundamentally from staple spun yarns in their measurement requirements. Key tests unique to filament yarns: denier per filament (DPF = total denier / filament count, measured by counting filaments in microscopy and dividing total dtex), filament uniformity (Uster Tester 6 at 400 m/min, CV% < 1.5% for flat filament, < 3.0% for DTY), filament breaks (broken filaments per 10,000 m causing fabric defects and downstream processing snags), crimp contraction CC% (DTY — percentage crimp retraction under standard 0.001 cN/dtex pretension versus 0.05 cN/dtex extended length, optimum CC 20–45%), crimp stability CS% (crimp contraction retained after boiling water treatment — CC measurement after 30 min 100°C immersion, CS > 80% for dyeing stability), boiling water shrinkage BWS (ISO 10799, 100°C 30 min under 0.05 cN/dtex, < 3% for well-drawn DTY), entanglement count (air-entanglement nodes per metre on partially interlaced yarn, optimum 40–80 per metre for weaving, 20–40 for knitting — measured by hook probe or ROTHSCHILD F-Meter), and finish oil content (lubricant % by weight, Soxhlet hexane extraction, optimum 0.3–0.6% for weaving warp filament). USTER Statistics 2023 provides benchmarks for PET flat filament 167 dtex, PET DTY 167 dtex, PA 6 flat 44 dtex, and PA 66 BCF across all evenness and tensile parameters.