Managing off Loom Crimp Contraction in Sized Flax Warps
Managing off-loom flax warp crimp contraction requires precise reed denting allowances, ELO tension tuning, and size solubility control to hit target grey widths.
Pick Crimp
Yarn Geometry
Structural curvature measurements track the waviness of weft yarns as they interlace with warp yarns in woven fabric. Evaluating the pick crimp is necessary for determining the elasticity and the tear strength of the finished linen cloth. This metric reflects the path length of the weft yarn compared to the actual width of the fabric.
Testing Procedure
Testing procedures use a crimp tester where a yarn of known length is extracted from the fabric and straightened under a specific load. The pick crimp is calculated as the percentage difference between the straightened yarn length and the width of the fabric sample. This measurement must be taken at multiple points across the width of the woven roll to account for variations in loom tension.
Fabric Performance
Fabric performance during subsequent finishing and garment making is affected by this geometric value. A high pick crimp increases the fabric’s horizontal stretch and comfort but can reduce the structural stability of the linen under load. Weaving mill operators adjust the warp tension and the shed timing on the loom to keep this value within the limits of the customer’s purchase order.
These technical details are saved in the loom’s digital recipe database to ensure batch-to-batch repeatability.