Structure Determination of Raw Flax Yarns for Warp Preparation
Evaluating raw flax yarn bundle morphology, pectin chemistry, and tensile metrics prevents high-speed warping breaks and protects loom hour efficiency.
Yarn Hairiness S3 Index
Surface Protrusion Parameter
Count of protruding fibre ends and loops exceeding a three-millimetre distance from the core yarn body quantifies surface hairy structure. Yarn hairiness S3 index provides an absolute numerical count of long protruding fibres per hundred metres of yarn measured by optical testing devices. Quality certificates cite S3 values as primary indicators of pilling propensity and yarn surface smoothness.
Fibre Protrusion Behavior
Short flax fibre ends and unattached bundle tips project outward from the compact yarn core during drafting and twisting. Higher counts of long protruding fibres increase friction during warping, lead to lint accumulation in reed dents, and cause end breaks on high-speed looms. Photoelectric testing head sensors count protruding fibres as the yarn passes through a light barrier at calibrated test speeds.
Wet spinning reduces S3 hairiness values compared to dry spinning because liquid immersion glues loose fibre ends onto the core during twist insertion. Singularly high S3 readings indicate worn drafting aprons, incorrect traveller weights or sub-optimal fibre blending in spinning prep lines.
Commercial Quality Boundary
Buyer purchase agreements for fine linen yarns enforce strict maximum limits on yarn hairiness S3 index figures. Laboratory test reports validate compliance before yarn lots leave the spinning mill for export weaving operations.