Determination of Bast Fiber Fineness via Standardized Low-Pressure Air Permeability
Low-pressure air permeability tests determine bast fiber fineness by measuring specific surface area across standardized compressed fiber plugs under ISO 2370.
WIRA Fiber Fineness Meter
Test Calibration
Pneumatic airflow resistance provides the baseline for measuring flax tow characteristics during preparatory spinning stages in Chinese textile mills. The wira fiber fineness meter establishes specific micronaire equivalent values by forcing compressed air through a weighed plug of bast material. Operators record resulting pressure drops inside the internal chamber on routine quality inspection sheets.
Micronaire values distinguish raw flax supply grades from finished yarn consistency requirements prior to commercial export. Mill acceptance thresholds differ significantly from overseas buyer contractual limits.
Resistance Mechanics
Porous plug permeability dictates the numerical output displayed on the digital readout panel. Compressed air flows through the cylindrical specimen holder at a regulated velocity. Resistance against the airflow increases proportionally with reduced cross sectional dimensions of individual elementary cells.
Heavy cellulosic bundles restrict passage more severely than fine commercial filaments. Calibrated manometers translate differential pressure readings into linear density estimates.
Export Verification
Finished flax slivers undergo strict laboratory scrutiny before container loading procedures begin. Inspection protocols verify compliance with international mercantile specifications stipulated in the sales contract. Technical certificates document average fineness parameters alongside moisture regain percentages.
Certified laboratory technicians stamp final shipping documentation after verifying sample conformity. Acceptance criteria demand strict adherence to agreed linear density tolerances.