Yarn Hairiness Testing
category
Yarn hairiness testing quantifies the length and density of fibres protruding from the yarn body — a surface property that determines weavability (sized warp hairiness reduction requirement), pilling propensity in fabrics (higher hairiness = higher pilling rate), dyeing appearance (hairy surfaces appear lighter due to light scattering), and handle (hairiness contributes to soft, fuzzy handle in fleece and flannel products). USTER Tester 6 hairiness H index (total length of protruding fibres per cm of yarn at 1 mm reference distance from yarn body, measured by optical sensor — laser diode, photodetector, signal proportional to scattered light from protruding fibres) and hairiness variation sH% (CV% of hairiness along yarn length — high sH indicates spindle or traveller problems). Zweigle G567 hairiness tester (counts protruding fibres at multiple reference distances: S1 = fibres >1 mm, S2 = fibres >2 mm, S3 = fibres >3 mm — separate counts at each threshold giving hairiness profile): S3 count per 100 m of yarn > 200 is minimum threshold for fabric pilling; S3 > 500 causes severe pilling in standard Martindale test. USTER Statistics 2023 H index benchmarks for Ne 30 ring cotton: 5th percentile H = 4.2 (export quality, low hairiness), 50th percentile H = 5.8 (average), 95th percentile H = 8.5 (high hairiness, pilling risk); compact ring yarn 25th percentile H = 2.5–3.5 (40–60% lower than standard ring).
Role
Yarn hairiness testing is the surface quality parameter most directly correlated with fabric pilling — the primary consumer complaint and brand quality failure in knitwear and knitted activewear — making H index and S3 count the quality specifications that distinguish premium compact-ring or vortex-spun yarns from standard ring yarns in the $80 billion global knitwear market.