Dynamic Hysteresis Loops in High Speed Flax Shedding and Moisture Adjusted Invoice Settlements
Dynamic flax shedding causes thermal moisture desorption, requiring invoice adjustments based on ISO 6741 oven-dry mass plus standard regain.
Flax Shedding Hysteresis
Dynamic Delay
Mechanical lag observed in the opening and closing of the warp shed indicates the internal friction and inelasticity of the yarn under tension. In a weaving environment, flax shedding hysteresis describes the difference in the warp tension path between the rising and falling harness frames.
Shedding Influence
Friction between the heddle eyes and the flax yarn heavily contributes to the development of this lag. As the loom speed increases, flax shedding hysteresis can cause the warp threads to vibrate or cling together. This behavior interferes with the clean passage of the filling yarn.
Weavers often apply specialized sizing agents to the warp to lubricate the fibers and minimize this effect.
Operational Constraint
Measurement of this tension difference occurs during the loom setup and adjustment phase. A high degree of flax shedding hysteresis requires the operator to increase the overall warp tension (but this increases the risk of yarn breakage). The boundary of effective operation is reached when the tension required to overcome the lag exceeds the tensile strength of the linen yarn.
Adjustments to the loom timing can help mitigate the impact of this physical property, provided the mechanic understands the relationship between harness motion and the relaxation behavior of the flax fibers during the brief interval of shed closure.