Tensile Threshold
Mechanical deformation under longitudinal load describes sized yarn elongation within the sizing department of a linen mill, measured immediately before the warp beam is mounted on the loom. Starch mixtures applied to flax fibres during sizing restrict elasticity to protect the yarn from abrasion during shuttle displacement. Testing equipment records the percentage increase in length until the treated single end snaps under tension.
Chinese export standards require recorded values to remain inside narrow statistical tolerances to prevent warp breakage during high speed weaving. Mill quality control sheets log these figures against ambient humidity levels to isolate moisture-induced elasticity variations from chemical film performance.
Elastic Recovery
Post-stress dimensional rebound represents sized yarn elongation behavior during cyclic shedding operations on projectile looms. Residual strain accumulates when sized flax strands undergo repeated tension peaks without sufficient relaxation time between cycles. Laboratory tension benches apply cyclic loading matching exact loom speeds to determine permanent set characteristics in the sized yarn lot.
Production supervisors compare mill testing logs against buyer acceptance criteria specified in the sales contract before grey cloth production begins. Exceeding maximum permitted elastic limits causes uneven fabric density and warp streaks in the finished linen goods.
Breaking Load
Ultimate mechanical resistance characterizes sized yarn elongation thresholds during destructive tensile testing protocols governed by national textile testing codes. Applied weight increases steadily until structural failure occurs within the conditioned flax sample length. Operators document both the maximum load and corresponding extension percentage on the daily laboratory audit report.
Buyer specifications demand higher breaking thresholds for warp yarns destined for heavy linen canvas than for fine dress fabrics. Final export certification depends entirely on these laboratory records matching the contractual quality parameters agreed prior to spinning and weaving.
