Adhesive Coating
Water-soluble synthetic polymers provide protective coatings that reinforce single linen yarns against the mechanical stresses of high-speed looms. Applying polyvinyl alcohol sizing adds tensile strength and lubricity to warp yarns before cloth manufacturing begins. This protective layer reduces yarn-on-yarn abrasion during the shedding cycle.
Application Method
Sizing cookers prepare the aqueous polymer solution at specific temperatures to ensure uniform viscosity and deposition on the yarn surface. Monitoring the concentration of polyvinyl alcohol sizing protects the flax yarn from becoming too stiff or too soft. Squeeze rollers press the hot liquor into the yarn core, leaving a uniform coating that must be dried immediately on heated cylinders.
Improper drying creates sticky yarns that cling together on the warp beam and cause warp-shedding faults.
Desizing Procedure
Fabric finishing requires the complete removal of all synthetic sizing agents to ensure uniform penetration of bleaching and dyeing chemicals. Aqueous washing at high temperatures dissolves the polyvinyl alcohol sizing without damaging the underlying cellulose structure. The wash water must be held above the gelation temperature of the polymer to prevent re-deposition on the linen fabric.
Effluent treatment plants must process the desizing wastewater to recover or degrade the synthetic polymers before disposal.
