Calibrating Flax Fibre Intake Standards for Dry Spinning
Dry spinning flax intake standards require strict bundle fineness under 2.2 tex, residual shive below 0.8 percent, and 11 percent target moisture regain.
ISO 2370 Airflow Method
Pneumatic Resistance
Standardized measurement protocols evaluate fiber fineness by passing a controlled stream of dry air through a compacted mass of plant fiber. The ISO 2370 airflow method determines the specific surface area and indirect linear density of flax fibers by measuring pressure drop across a prepared fiber plug. Finer fibers present greater surface area per unit mass, resulting in higher resistance to airflow and greater measured pressure differentials.
The method stops yielding valid results when fiber samples contain excessive shives or non-uniform moisture levels.
Compressibility Profile
Standard specimen compression into a fixed volume chamber forms the foundation for repeatable airflow resistance measurements. When applying the ISO 2370 airflow method, operators weigh a precise mass of cleaned flax fiber and compress it into a cylindrical test cell. Air at a controlled volume and pressure flows through the compressed specimen while sensors record the differential head loss.
Calibration curves convert differential pressure readings directly into fiber fineness values expressed in tex or specific surface units. Because raw flax contains residual pectins and variable fiber bundle division, specimen preparation requires careful hand carding to remove dust and unhackled straw prior to testing. Repeat measurements across multiple subsamples ensure representative fineness figures for large commercial fiber lots.
Fineness Calibration
Reference standards calibrated against microscopic cross-sectional analyses ensure instrument accuracy across testing facilities. Applying the ISO 2370 airflow method allows spinning mills to sort incoming flax lots into precise fineness categories for sliver blending. Measurement validity depends on strict maintenance of standard atmospheric conditions during sample conditioning and testing.