Airflow Porosimetry Calibration Parameters for Unhackled Dew-Retted Long Flax Bundles
Precise airflow porosimetry of unhackled dew-retted flax requires axial strick alignment, controlled 196 kPa compaction, and 12 percent regain normalization.
Unhackled Flax Stricks
Fibre State
Bundles of harvested flax that have been scutched but not yet combed exist in a coarse and semi-aligned state. These unhackled flax stricks consist of long, parallel linen fibres that still contain small amounts of woody tissue and shorter, tangled fibres. Spinning mills purchase these raw bundles directly from scutching mills before any fine carding or drawing begins.
This material represents the raw, unrefined state of the long fibre line, which must undergo further combing to be suitable for high-grade yarn. It requires careful storage to prevent moisture absorption and fungal decay during transit and warehousing.
Preparation Stage
Combing these bundles removes the remaining short fibres and trash, turning the coarse material into a smooth ribbon of clean fibre. Passing the unhackled flax stricks through a series of increasingly fine metal pins or hackling boards aligns the long fibres and separates them from the shorter tow. This process is necessary to produce the fine, long-staple linen required for high-end apparel and home textiles.
Industrial Grading
Inspectors evaluate these raw bundles by hand to determine their average length, strength and cleanliness before they enter the hackling machine. The grade assigned to the unhackled flax stricks determines the yarn count that can be spun from them and the price the mill pays. This evaluation ensures that the mill uses the appropriate grade of raw material for the intended fabric quality.