Quantifying Anti Friction Lubricant Protection Limits for Elastane Cores under High Drag Jet Processing
Sustaining a 1.8 percent ester lubricant film on elastane cores prevents elastomeric rupture when jet nozzle pressure exceeds 2.2 bar.
Boundary Lubrication
Contact Mechanics
A friction regime occurring during the spinning and twisting of staple fibers where surface asperities remain partially separated by an extremely thin fluid layer without establishing full hydrodynamic pressure. Slippage relies heavily on the direct mechanical contact of protruding microfibers against adjacent strands within drafting rollers. Applied normal force pushes lubricant molecules aside until microscopic peaks touch directly, generating localized high shear resistance that dictates the drafting force required by the frame.
Friction Coefficient
Quantifying values drop significantly below dry sliding levels yet remain higher than pure hydrodynamic flotation due to solid friction contributions from intersecting filaments. Mill technicians measure this ratio on draw frames by recording the pulling tension necessary to draw sliver through ceramic guides under controlled moisture conditions. Operating windows span narrow boundaries, shifting rapidly toward seizure if lubricant film thickness falls below combined surface roughness values of the interacting metallic and textile elements.
Viscosity Control
Fluid film maintenance depends directly upon lubricant carrier viscosity and delivery rate applied during the sizing or spin finish stage before carding. Higher base fluid density preserves separation between metal traveler rings and high speed yarn paths, suppressing thermal degradation during extended running hours. Shear thinning behavior ensures the compound flows easily through application nozzles while recovering sufficient body under high contact pressures inside ring spinning zones.
Surface Separation
Preventing metallic abrasion on knitting needles requires maintaining specific molecular film thicknesses that exceed the combined peak height of interacting steel and yarn surfaces. Processing synthetic filaments under marginal fluid coverage accelerates needle groove wear and generates yarn breaks from uncontrolled stick slip fluctuations. Thermal stability of the chosen finishing oil dictates whether the boundary layer survives localized frictional heating generated during high speed loop formation on circular knitting machinery.