Yarn Hairiness and Measurement
topic
Yarn hairiness is the total length of protruding fibres per unit yarn length, measured by the Uster Tester as H (mean hairiness, mm/mm) and S3 (fibres longer than 3 mm per cm, the most quality-critical parameter). Typical H values: 4–8 for ring-spun, 2–4 for compact-spun cotton at 30 Ne. Hairiness increases with coarser count, higher spindle speed, rougher traveller, and longer fibre length. Hairiness causes: fabric pilling (loose hairy fibres tangle into pills), weaving shed contamination, and uneven dyeing.
Role
Yarn hairiness is the key parameter distinguishing ring-spun from compact-spun yarn quality and is the primary technical argument for compact spinning investment. Hairiness directly causes fabric pilling — the most common consumer complaint about cotton knitwear — and increases warp breakage rate in weaving. Specifying maximum S3 hairiness in yarn purchase contracts is standard in premium apparel yarn sourcing.