Mechanical Fatigue
Repeated application of tension to a textile strand during high-speed winding or fabric formation simulates the primary mechanical stress experienced by yarn in a production environment. Applying a cyclic tensile load to flax yarn measures its resistance to fatigue before failure occurs. This evaluation mimics the action of the loom where the warp yarn is raised and lowered continuously.
Dynamic testing reveals the elastic recovery of the flax fibers under tension.
Fibre Elasticity
Molecular structure of flax, which consists of highly aligned crystalline cellulose chains, yields high strength but low elasticity under tension. When subjected to a cyclic tensile load, the fibers undergo gradual structural damage, which initiates microscopic cracks within the cell walls. Over many cycles, these micro-cracks grow and merge until the yarn breaks under a tension far below its static breaking strength.
High-speed spinning mills use these fatigue metrics to predict the frequency of yarn breakages during subsequent high-tension interlacing operations, because a single break halts the entire loom. This damage is especially pronounced in dry-spun yarns where the lack of moisture limits the natural flexibility of the flax fibers.
Loom Adjustment
Control of tension settings on the warping machine and loom must stay below the critical fatigue threshold of the selected yarn lot. Adjusting the shed geometry reduces the peak stress during each cycle of the loom. Regular mechanical audits ensure that the warp tension remains within these determined limits, which increases overall fabric productivity.
