Mechanical Motion
Dynamic study of the movement and positioning of the rear yarn guide in a loom defines how the machine manages warp tension during each cycle. Precise whip roll kinematics allow the backrest to move in synchronization with the shedding motion to equalize the path length of the yarn. This prevents sudden spikes in tension that could snap delicate linen threads.
Tension Management
Motion of the roll is usually controlled by a cam or an electronic actuator that responds to the position of the crankshaft. As the shed opens, the whip roll moves forward to release extra yarn length, and it moves back as the shed closes to take up the slack. If the movement is mistimed, the fabric will show ripples or uneven density because the beat-up force will vary across the picks.
Modern looms use sensors to track the warp tension in real time and adjust the roll position automatically to maintain a constant load.
Synchronization Limit
Optimizing this movement requires a deep understanding of the elasticity of the specific flax yarn being used. A stiffer yarn requires a more aggressive movement of the roll to compensate for its lack of natural stretch. The analysis is complete when the tension sensors show a flat profile throughout the entire rotation of the loom.
