Tensile Stretch
During the mechanical processing of flax yarn in Chinese spinning mills, yarn elongation defines the proportional increase in length that occurs before the strand breaks under tension. This physical property determines how well spun flax withstands the high speed forces imposed by ring frames and automatic winders. Operators record these extension values on the mill inspection sheet alongside breaking tenacity to predict loom performance.
Insufficient extensibility causes frequent warp breakage during sizing and weaving. Excessive stretch creates uneven fabric density and irregular shrinkage during wet finishing.
Breaking Boundary
Testing technicians measure this metric on standard dynamometers using fixed gauge lengths and constant rates of extension. The resulting force extension curve establishes the maximum load capacity and the corresponding percentage of stretch at the rupture point. Flax fibers possess lower natural elasticity than synthetic alternatives, which restricts the allowable tolerance window during high tension drafting.
Quality controllers distinguish between raw fiber breaking elongation and processed yarn elongation because twisting alters the internal geometry of the strand.
Acceptance Criteria
Mill technical managers enforce strict internal standards for elongation to satisfy export buyer specifications for linen fabric. Buyers set minimum percentage thresholds in the sales contract to guarantee that finished garments maintain dimensional stability after laundering. Shipments failing to meet these contractual limits are rejected at the finishing stage before final packaging and international transport.
