Synthetic Staple Fibre Testing
category
Synthetic staple fibre testing measures linear density, tenacity, elongation, crimp parameters, thermal shrinkage, and cross-sectional geometry of polyester, polyamide, polypropylene, and acrylic staple fibres to verify compliance with spinning mill purchase specifications and end-use performance requirements. Linear density (dtex, ISO 1973: weigh 50 fibres of measured length, dtex = mass (mg) × 100 / length (mm) × 5 × 10⁻³ — alternatively automated Textechno Vibromat M resonance vibration method, ±0.5% accuracy in 10 seconds per fibre). Tenacity and elongation (Textechno Favimat+, ISO 5079: 20 mm gauge, 20 mm/min extension, 50 tests per sample — polyester 6.7 dtex tenacity 35–50 cN/tex CV% <8%, elongation 40–60% CV% <10%; polyamide 3.3 dtex tenacity 45–60 cN/tex). Crimp frequency (CF, IWTO-19 adapted or ISO 38: crimp arcs per 25 mm under 0.5 mg/dtex pretension, optimum 5–9 arcs/cm for polyester blended with cotton; higher crimp 10–14 for high-bulk acrylic) and crimp modulus (% extension to uncrimp ÷ original length, optimum 60–85% for polyester apparel staple). Thermal shrinkage (boiling water shrinkage BWS, ISO 10799: 1 m yarn hank, 0.05 cN/dtex pretension, 30 min in 100°C water — PET BWS < 3% for normal spinning, > 6% signals inadequate draw ratio during fibre production; dry heat shrinkage at 160°C, 30 min).
Role
Synthetic staple fibre testing provides the incoming quality assurance data that spinning mills use to accept or reject polyester and nylon staple shipments — with fineness CV%, crimp frequency, and thermal shrinkage deviations from specification causing processing problems (card lapping, drafting unevenness, fabric width variation in heat setting) that cost $0.05–0.20/kg in mill rework and reprocessing.