Flax Cell Wall Microfibril Alignment Determination Methods
X-ray scattering and polarized Raman spectroscopy determine flax microfibril angles to project spinning performance and yarn tenacity.
Decortication Damage
Structural Defect
Physical fiber trauma describes the fracturing and splitting of flax bast tissues during the mechanical separation of the outer fiber bundles from the woody core. When the extraction rollers or scutching blades apply excessive crushing forces, decortication damage occurs as micro-cracks in the cellulosic cell walls. This reduces the yield of long line flax and increases the proportion of short fibers that must be diverted to secondary lower value markets.
Mills assess this damage before spinning because weakened fiber sections cannot sustain high speed wet drafting without frequent breaks. The mechanical stresses tear the primary wall, which exposes the underlying crystalline layers to chemical degradation during bleaching.
Milling Severity
Heavy scutching action increases output rates but risks degrading the fiber bundle strength. If the decortication damage is high, the subsequent drawing and combing stages yield excessive quantities of tow. These shorter tow fragments require separate dry spinning processes that produce uneven yarn with lower tensile strength.
Spinners monitor the ratio of line fiber to tow in the raw deliveries to gauge the extent of the damage.
Quality Threshold
Acceptance limits in purchasing agreements dictate the maximum permissible fiber fragmentation. Lab tests measure the loss of tensile strength in scutching trials to identify high damage lots. If the flax fails these thresholds, the lot is downgraded from high grade warp yarn application to coarser weft or blend yarns.
This maintains mill efficiency by routing damaged fibers to appropriate processes.