Sizing Agent Selection for Fine Spun Bast Yarns
Optimal fine bast yarn sizing requires balancing PVA and CMC polymers to achieve eleven percent dry add-on without causing warp brittleness.
Hairiness Encapsulation
Fibre Containment Mechanism
Sizing processes designed to bind protruding fibre ends to the yarn body prevent fuzzy surface textures and reduce yarn friction. Effective hairiness encapsulation is achieved by applying a cohesive starch or polymer film that wraps around the yarn core. This action secures the loose flax fibrils, which otherwise would stick out and catch on adjacent yarns during loom operation.
Process Operation
Viscous sizing liquor applied in the sow box coats the yarn, forming a protective jacket as it dries. During hairiness encapsulation, the liquid film must be thick enough to cover the protruding fibres but flexible enough not to crack under tension. When the yarn passes through the squeeze rollers, the sizing is pressed into the yarn structure, flattening the hairs along the main axis.
This mechanical pressing, combined with the adhesive properties of the size, prevents the fibres from rising again. Loom productivity increases because the smooth, encapsulated yarns slide past each other without clinging.
Loom Advantage
Friction between adjacent warp yarns is minimized when the protruding flax fibrils are locked down. Successful hairiness encapsulation prevents the formation of lint and dust in the warp shed. This maintains the structural integrity of the yarns throughout the entire fabric manufacturing cycle.