Optimizing Warp Sizing Polymer Add-on Levels for Air-Jet Weaving Efficiency
Optimizing sizing polymer add-on levels balances yarn hairiness reduction against shed dusting to maximize air-jet loom efficiency and lower desizing costs.
Polyvinyl Alcohol Hydrolysis
Degree Saponification
Chemical cleavage of acetate groups from polyvinyl acetate precursor molecules determines the percentage of hydroxyl functional groups remaining along the polymer backbone. The specific degree of polyvinyl alcohol hydrolysis dictates whether the resin behaves as a fully hydrolyzed grade at ninety-eight percent or a partially hydrolyzed grade at eighty-eight percent. Sizing chemists select specific hydrolysis levels to balance water solubility against mechanical film strength on filament warps.
Residual acetate groups modify polymer crystallinity and film flexibility.
Solubility Behavior
Cold-water dissolution improves significantly when residual hydrophobic acetate groups interrupt intermolecular hydrogen bonding in partially saponified polymers. Utilizing resins with partial polyvinyl alcohol hydrolysis allows rapid cooking at eighty degrees Celsius without requiring high-pressure jet cookers. Fully hydrolyzed variants demand near-boiling temperatures for complete dissolution.
Desizing Washability
Synthetic sizing removal during grey fabric preparation relies on rapid re-hydration of dry size films deposited on warp yarns. Higher levels of polyvinyl alcohol hydrolysis produce tough, crystalline films that require hot alkaline wash liquor for complete removal. Incomplete washing leaves harsh spots that cause uneven dye absorption.
Adhesion Boundary
Interfacial bonding strength between sizing polymers and synthetic fibers peaks at specific saponification levels. Selecting optimal polyvinyl alcohol hydrolysis grades ensures strong adhesion to hydrophobic polyester and nylon filaments during high-speed weaving. Poor adhesion causes film shedding.