Textile Formula
Mathematical determinations of the percentage length change when a yarn is straightened from its crimped state provide the basis for yarn length purchasing agreements. Standardizing the crimp take up calculation allows mills to predict the raw yarn length needed to weave a specific yardage of finished fabric. This value is expressed as a percentage of the straightened yarn length and acts as a baseline for costing crimped fibers.
Execution Steps
The process begins by measuring the crimped yarn under a nominal pretension, after which a heavier load is applied to remove all crimp without stretching the fiber. Through the crimp take up calculation, the technician compares these two lengths to derive the crimp percentage. Accurate load application is essential because excess weight will cause elastic yarn stretching.
Weaving Application
High values in this calculation correspond to fabrics with greater thickness and recovery properties. Utilizing the crimp take up calculation helps warp preparation departments set the correct tension on the creels. This prevents yarn breaks during high-speed weaving.
Inspection Protocol
Quality inspectors verify these values on incoming yarn shipments to ensure consistency between different spinning lots. Any discrepancy highlighted by the crimp take up calculation indicates a variation in the heat-setting stage of yarn texturing. This variation can lead to uneven fabric dyeing if left uncorrected.
