Standard Moisture Regain Determination in Scutched Flax Fibre
Standard moisture regain in scutched flax fibre is set at 12.0% of bone-dry mass using ISO 6741-1 forced-convection oven drying at 105 degrees Celsius.
Shive Moisture Retention
Moisture Absorption
Hygroscopic properties govern how plant cellular debris absorbs and retains water during mechanical and chemical flax processing. Evaluating shive moisture retention measures the equilibrium water content held within residual woody core fragments present in flax fibre. Scutching mills and spinning facilities monitor this retention behavior because moist shive particles adhere strongly to usable bast strands.
Woody core fragments absorb moisture faster and release it slower than surrounding bast fibres, creating localized moisture damp spots. The measurement scope applies exclusively to non-bast woody inclusions within raw or partially processed flax stock.
Processing Impact
Mechanical decortication and carding separate woody stem fragments from bast fibre bundles. When high shive moisture retention occurs, wet woody particles swell and resist mechanical cleaning pins on carding drums. High internal moisture makes shive soft and flexible, causing it to pass through turbine beaters without detaching from long line flax.
As the fibre dries during rove preparation, shive loses moisture and becomes brittle, dropping off during spinning and causing localized yarn count drops or end breaks. Mill technicians adjust drying oven temperatures and humidity control in carding rooms to stabilize moisture levels in raw fibre lots. Tracking shive water retention helps mills calculate net clean fibre yields and fine-tune mechanical pin settings on hackling frames.
Quality Constraint
Quality control laboratories establish strict thresholds for acceptable residue moisture content before fiber drafting. High shive moisture retention during wet spinning causes localized dye resistance, creating light specks on finished woven linen fabric. Technical specification sheets set maximum allowable shive moisture limits to ensure uniform yarn drying and defect-free fabric finishing.