Standardized Air Permeability Test Parameters for Raw Flax Bundles
Air permeability fineness tests for raw flax require strict 65 percent RH conditioning, precise chamber packing density, and pre-cleaning of shive debris.
Volumetric Flow Rate
Fluid Velocity
Fluid volume passing through a given conduit cross-section per unit time defines circulation capacity in wet processing equipment. Package dyeing and yarn bleaching machines adjust volumetric flow rate to achieve uniform chemical penetration through dense linen yarn packages. Recirculating liquor pumps move dye solutions through stainless steel yarn spindles at prescribed rates measured in litres per minute per kilogram of yarn.
Insufficient flow rates cause shade variation between inner and outer bobbin layers, while excessive flow damages soft yarn packages.
Process Control
Automated dyeing controllers monitor volumetric flow rate using electromagnetic flow meters installed in main liquor feed lines. Flow direction reverses periodically during treatment cycles, requiring balanced volume delivery in both inside-out and outside-in directions. Scouring logs record differential pressure and flow metrics to verify thorough pectin extraction from heavy flax yarns.
Process parameters specified in buyer dye-matching agreements define minimum flow volumes based on package density and yarn count. Deviations from target flow rates trigger automatic pump adjustments to maintain constant liquor exchange throughout the boil.
System Calibration
Drying efficiency in forced-air package dryers depends directly on air volume delivered through wet yarn beds. Correct volumetric flow rate prevents localized overheating and ensures consistent residual moisture across entire batch charges. Mill maintenance protocols verify flow meter calibration quarterly using ultrasonic flow sensors.