Fine Wet Spun Flax Tenacity and Fibre Morphology
Fine wet-spun flax yarn tenacity depends on controlled pectin softening in the trough, allowing technical bundles to divide into fine elementary cells during draft.
Dislocation Kink Band
Fiber Defect
Structural defects in bast fibres occur when cellulose microfibrils undergo localized buckling or misalignment under compressive stress. These areas of disruption, often referred to as a dislocation kink band, create weak points along the length of the flax filament. They are visible under polarized light microscopy as bright bands running transverse to the fibre axis.
The frequency of these defects directly influences the spinning performance of the material. When fibers are highly defective, the rate of yarn breakage during spinning increases, which leads to machine downtime and uneven yarn quality. Wet spinning processes exacerbate these vulnerabilities by swelling the fiber structure and exposing the compromised regions to mechanical stress.
Mechanical Origin
Compressive forces encountered during mechanical processing or harvesting induce these structural flaws. When flax stems are bent excessively during pulling or scutching, the brittle crystalline regions in the cell wall buckle under the load. A dislocation kink band represents a permanent deformation of the fibre structure.
Fibre flexion during high-speed decortication increases the density of these damage sites.
Processing Consequence
Spinning mills must monitor these defects because they act as initiation sites for fibre breakage during yarn drafting. Bleaching and acid treatments preferentially attack these disrupted regions, which exposes the fibre to deeper chemical degradation. This localized attack leads to uneven dyeing and reduced tensile strength in the finished woven fabric.
Selecting gentle extraction methods minimizes the formation of these weak points and ensures the production of high-grade yarn.