Plastic Deformation
The slow, continuous elongation of a textile yarn under a constant mechanical load is a time-dependent deformation that occurs after the initial elastic response. In flax yarns, secondary creep represents the permanent stretching of the cellulose fibers under long-term tension during the weaving or winding process. This deformation is irreversible and alters the mechanical properties of the yarn.
Laboratory test reports record this creep behavior to assess yarn stability under prolonged stress.
Mechanical Behavior
When warp yarns remain under high tension for several hours on a stopped loom, they undergo this permanent elongation. The occurrence of secondary creep reduces the remaining elasticity of the linen yarn, making it more brittle and prone to failure when the loom is restarted. Mill technicians must minimize loom downtime to prevent localized sections of the warp from developing uneven tension.
To control this strain, the yarn’s relaxation properties must be analyzed under simulated loom conditions, and the results filed in the spinning mill’s research log, helping weavers choose the best tension profiles for different linen styles.
Tension Control
Sizing the yarns with protective starch coatings helps to minimize this slow deformation by reinforcing the fiber structure. This protective measure is recorded in the warp preparation document. Proper sizing ensures that the yarn retains its dimensional stability throughout the weaving process.
