Fibre Protrusion
Presence of unbound fibre ends extending from the main body of the warp yarn increases the risk of yarn entanglement during cloth manufacture. Spinning mills measure warp hairiness to predict how smoothly the yarn will pass through the loom’s healds and reed. This surface defect is more pronounced in linen yarns because flax fibres are relatively stiff and difficult to bind.
Its reduction is achieved through proper twist insertion and sizing.
Mechanical Interaction
When the loom’s shed opens and closes, protruding fibres on adjacent warp yarns can cling to each other, creating a cling defect that prevents a clean shed from forming. This entanglement blocks the weft insertion carrier, which causes yarn breakage or stops the machine. High warp hairiness also leads to increased lint accumulation around the loom, requiring frequent cleaning to prevent dust-related machinery malfunctions.
Applying a protective starch or polymer coating during the sizing process lays these loose fibres down along the yarn core, creating a smooth surface that reduces friction. This chemical treatment is the primary method used to control surface defects before loom operations.
Sizing Influence
Yarn testers count the number of protruding fibres per meter using optical sensors. This data is used by the mill to adjust the wet-spinning draft. Low hairiness values improve the efficiency of the loom room.
