Output Ratio
Mechanical combing recovery calculates the percentage of combed line flax fibre extracted from raw scutched flax straw. Long-line hackling yield efficiency measures the net mass of parallelized, detrashed long fibres obtained relative to the initial mass of raw scutched stricks fed into the hackling machine. This operational ratio isolates the raw fibre quality and machine comb pin sharpness before sliver formation begins.
Combing waste falling below the pins is collected as hackled tow for secondary carding operations.
Processing Mechanics
Raw flax bundles enter the machine clamped in moving metal holders, where rotating pinned aprons comb the root and top ends sequentially. Pin density increases progressively through successive grading zones to split coarse fibre bundles without breaking individual technical filaments. Brittle or poorly retted flax fractures excessively under aggressive pin action, depressing long-line extraction percentages and increasing coarse tow drop.
Technicians adjust machine comb velocity, pin penetration depth, and apron clearance based on bundle strength data from incoming raw bale reports. Proper relative humidity within the hackling hall prevents flax bundle breakage caused by static drying.
Production Ledger
Spinning mill supervisors record input bale weights and output sliver yields daily on hackling department batch sheets. High-grade French or Belgian scutched flax typically delivers long-line extraction rates between forty-five and fifty-five percent of fed material mass. Mill managers compare this balance figure against standard cost sheets to evaluate supplier retting quality and machine pin maintenance schedules.
