Stress Exchange
The transition of waviness from one set of yarn threads to another under mechanical tension defines the structural behavior of woven textiles during processing. During the weaving and finishing of linen cloth, crimp inversion occurs when tension applied to the warp yarns pulls them straight, forcing the weft yarns to bend and take on more crimp. This reciprocal relationship between the warp and weft determines the dimensional stability and stretch of the fabric.
In Chinese mills, controlling this structural change prevents the fabric from shrinking unevenly during the bleaching and dyeing stages.
Mill Monitoring
Technicians measure this phenomenon on the finishing line by comparing the crimp percentage of the warp before and after fabric tensioning. This check utilizes a fabric crimp tester to strip yarns from a known length of cloth, straighten them under a specific load, and calculate the length difference. Inaccurate tension settings on the tentering machine can force an excessive exchange of crimp, leading to skewing or bowing of the fabric width.
Adjusting the overfeed rollers on the stenter frame allows the mill to regulate this stress transfer.
Finished Quality
Documenting this parameter on the final inspection sheet records the warp and weft shrinkage values as a guarantee of structural integrity. Failure to control this parameter results in fabric that distorts during garment manufacture or shrinks excessively during first laundering. The finished cloth must meet the buyer’s criteria to avoid rejection.
