Ends and Picks That Deliver a Target Weight in Linen
Target linen weight depends on yarn tex, ends, picks, and crimp contraction; calculating raw count without finishing shrinkage overshoots mass targets.
Sizing Starch Add On
Protective Dosage
Application of starch to warp yarns increases their strength and resistance to abrasion during the weaving process. The sizing starch add on is the percentage increase in dry yarn weight due to the presence of the sizing agent on the warp sheet. This value must be controlled within tight limits to ensure the yarn is strong enough to weave without being too stiff or brittle.
Operational Optimization
Flax yarns typically require a higher sizing starch add on than cotton yarns because of their naturally high stiffness and hairiness. In the sizing department, the processor adjusts the squeeze roll pressure and the viscosity of the starch bath to achieve the target percentage. If the amount of starch added is too low, the yarns will break frequently on the loom due to inadequate protection against friction.
If the amount is too high, the yarn loses its elasticity, which can lead to brittle breaks at high warp tensions.
Application Control
Sizing laboratories determine the starch quantity by desizing a sample of the yarn and calculating the weight difference. Sizing starch add on values of seven to twelve percent are typical for linen warp. Consistent application reduces warp breaks during subsequent processing.