Transient Loading
Rapid, short-duration increases in warp yarn tension occur during the shedding and beat-up actions of the weaving cycle. These dynamic stress spikes can exceed the elastic limit of linen yarns, which have low extension at break. This variable represents the extreme forces that occur when the loom transitions from shed opening to weft insertion.
Mill technicians monitor these peaks using specialized electronic sensors attached to the warp line.
Yarn Failure
If the loom operates at high speed, these sudden tension surges can cause immediate yarn breakages, especially at weak points like yarn splices or thick slubs. To manage dynamic stress spikes, mills use soft shedding profiles and spring-loaded back rests that absorb the sudden forces. This dampening is particularly important for linen because flax fibers do not have the high elasticity of cotton or wool.
The results of these tension trials are recorded in the mill’s machine optimization logs, which guides the choice of sizing agent used to coat the warp yarns before weaving.
Machine Setting
Adjusting the dampening tensioners reduces the amplitude of these spikes to keep the yarn within its safe limits. This mechanical optimization is listed in the loom maintenance program. Keeping these spikes low increases the lifetime of both the yarn and the loom parts.
