Fundamental Linen Lea Conversions and Metric Yarn Calculations
Linen Lea converts to Metric count via NeL multiplied by 0.604772, while direct Tex equals 1653.52 divided by NeL, adjusted for 12% moisture regain.
Crimp Contraction Percentage
Structural Retraction
Yarn retraction measurements quantify the shortening of a thread after it has been textured or woven into a fabric structure. Textile mills calculate the crimp contraction percentage to evaluate how much the yarn will pull back during subsequent processing. This shrinkage affects both the hand and the density of finished linen fabrics.
Production logs and quality control records document this value to maintain uniformity.
Tension Effect
The laboratory procedure requires applying a specific heavy load to straighten the yarn, followed by a lighter load to let it recover its crimped state. Technicians measure the length difference between these two states to determine the physical contraction. In Chinese spinning mills, this metric is critical for adjusting the tension settings on high speed winding machines.
Proper calibration prevents excessive yarn breakage during the weaving phase. It also ensures that the final product maintains its physical elasticity during the high temperature finishing processes where the linen yarn is subjected to wet heat. Weaving managers use these laboratory findings to adjust the warp tension on the factory floor.
Fabric Yield
Fabric yield and density calculations depend on the corrected length of the yarn after shrinkage is accounted for in the loom layout. When crimp contraction percentage is higher than the buyer’s tolerance limit, the resulting fabric will be narrower and heavier than requested. The weaver must adjust the warp yarn length on the beam to compensate for this physical behavior.
These modifications are recorded on the weaving mill’s loom setup sheet before warp preparation.