Standard Linen Yarn Tensile Specifications for Weaving Preparation
Wet-spun linen warps demand a minimum tenacity of 18.5 cN/tex with under 1.2% beaming stretch to maintain loom stop rates below 1.5 per 100,000 picks.
Beaming Stretch
Elongation Control
Tension-induced elongation during the winding of yarn onto a loom beam represents a critical variable in warp preparation. This mechanical deformation, known as beaming stretch, occurs when warp yarns are pulled from the sizing machine or creel to the beam. Controlling this elongation ensures that the yarn retains its natural elasticity for the subsequent weaving process.
Quality Variance
Excessive tension during this stage causes permanent deformation of the flax fibres, which reduces the residual elongation of the warp yarn. This loss of elasticity leads to high break rates during weaving because the yarn cannot stretch when the loom shed opens. Conversely, insufficient tension creates a loose warp beam that causes yarn tangling and uneven tension during weaving, which yields a fabric with structural defects and inconsistent density across its width.
Regular calibration of the brake systems is necessary to maintain the balance of forces.
Tension Regulation
Mills use electronic sensors and differential drives on the beaming machine to monitor and adjust the tension dynamically. The target elongation is usually kept below one percent for flax yarns to prevent structural damage to the bast fibres. Maintaining this low level of stretch improves the weaving efficiency of linen looms.