Characterizing Viscoelastic Size Film Fracture Dynamics under High Frequency Air Jet Shedding Stresses
Viscoelastic size film failure under high frequency air jet shedding stems from dynamic glass transition shift and energy dissipation limits.
Hydroxyethyl Starch
Starch Addition
Polymer modification occurs during wet sizing preparations when modifying agents are introduced to flax yarn sizing baths. Hydroxyethyl starch functions as a film forming modifier in Chinese linen weaving mills, altering gelatinisation temperatures and improving warp yarn tensile strength on high speed looms. Sizing supervisors measure substitution degrees through polarimetric analysis to confirm etherification levels match mill production specifications.
Higher molar substitution values restrict retrogradation tendencies during prolonged storage periods inside humid preparation rooms. Viscosity stability remains essential for maintaining consistent pickup rates across fine wet spun linen warps.
Sizing Bath Control
Aqueous polymer solutions require strict temperature monitoring throughout continuous cooking cycles in size kitchens. Hydroxyethyl starch dissolves readily at lower thermal thresholds compared to native potato or corn starches. Preparation operators record gelatinisation profiles inside production logs before releasing sizing liquors to weaving sheds.
Incomplete etherification leaves unswollen granules behind, which causes uneven film deposition along yarn surfaces and leads to broken filaments during shedding motions.
Warp Performance
Sizing efficiency depends on adequate penetration into flax fibre bundles combined with uniform surface encapsulation. Hydroxyethyl starch forms flexible elastic films that withstand repeated mechanical abrasion from heald frames and reed wires. Weaving inspectors evaluate grey cloth quality by counting warp break frequencies per loom hour during industrial trials.
Residual sizing agents wash out easily during subsequent alkaline scouring stages without leaving insoluble residues that interfere with reactive dyeing processes.
Yarn Count and Sizing Chemistry in Warp Preparation
Warp sizing requires matching yarn packing factor to polymer viscosity, adjusting squeeze nip pressure for precise solids add-on, and maintaining elongation.