Evaluating Dynamic Friction Limits in Fine Wet Spun Linen Warps
Dynamic friction in fine wet spun linen warps limits loom speed, demanding tailored size films, optimized shedding angles, and ambient humidity control.
Stick Slip Phenomenon
Periodic Oscillation
Frictional behavior during fiber processing creates intermittent movement between the flax strands and the metal surfaces of the spinning machinery. The stick slip phenomenon occurs when the static friction between the fibers exceeds the kinetic friction during the drafting process, leading to uneven yarn thickness and potential breakage in the spinning frame.
Frictional Resistance
Molecular interactions between the lignified components of the flax and the equipment surface drive these periodic changes in tension. When the drafting rollers pull the fiber bundle, the resistance builds until the fibers suddenly slide forward. This jerky movement prevents the formation of a smooth, consistent yarn profile.
Spinners apply specific lubricants to the flax to reduce the difference between the two types of friction. Monitoring the temperature of the drafting zone helps in managing this effect during high speed production. Detailed analysis of the force curves reveals the frequency and amplitude of these sliding events.
Yarn Quality
Quality control logs record the frequency of tension spikes caused by these frictional changes. Excessive stick slip phenomenon leads to a high coefficient of variation in the final yarn count. Fabrics woven from such yarns often show a streaky appearance after the dyeing process.