Protective Coating
Warp sizing efficacy on spun flax yarns is measured against raw thread surface roughness values to determine how completely film-forming polymers cover exposed outer fibres. Achieving optimal sizing film encapsulation creates a continuous protective sheath around the linen strand while controlling binder penetration into the yarn core. Slashing departments log sizing add-on percentages and coating uniformity metrics on slashing process control sheets.
The process defines physical surface coating during warp preparation and excludes chemical cross-linking treatments applied during final fabric finishing.
Adhesion Mechanism
Spun flax yarns present uneven cross-sections and protruding fibre ends that resist smooth coating formation during liquid size application in the size box. Complete sizing film encapsulation requires low-viscosity polymer formulations that wet flax cellulose efficiently before solidifying on squeeze rollers and drying cylinders. When sizing agents fail to form a continuous surface film, high loom tensions tear exposed flax fibres, causing severe shedding and high end-breakage rates during loom runs.
Slashing machine parameters like squeeze roll pressure and drying cylinder speed are adjusted to balance surface coating against core penetration. Laboratory personnel test sized warp samples for size add-on weight and abrasion resistance to verify film integrity before loom beam mounting.
Desizing Boundary
Incomplete film removal during fabric preparation prevents uniform dye liquor absorption and causes cloudiness in finished linen piece goods. Sizing polymers must be soluble in hot enzymatic desizing baths to ensure total film removal prior to bleaching operations.
