Physical Imperfection
Physical imperfection in a woven textile that occurs when a loom resumes operation after a stop. The start marks fabric defect is caused by a momentary shift in the fell line position or a change in warp tension. It is particularly noticeable in plain weave linens due to their crisp structure.
Mechanical Cause
When the loom stops the warp yarns undergo stress relaxation which alters the tension balance. This start marks fabric defect appears if the first few picks are not beaten into the cloth with the same force as those before the stop. Electronic control systems attempt to compensate by moving the take-up roll slightly before the first pick.
The duration of the stop also influences the severity of the mark because the flax fibres continue to creep under load.
Quality Control
Inspectors flag the start marks fabric defect as a major flaw if it exceeds the length specified in the four point system. Reducing the frequency of loom stops is the primary way to minimize this problem. Training weavers to manually adjust the fell line before restarting can also help mitigate the impact.
Every roll of linen is checked against a light table to identify these density variations before they reach the finishing plant.
