Allowed Variance
A permissible variance margin defines the limits within which physical characteristics of consecutive flax spinning lots may deviate from the contract master sample. This batch tolerance window dictates the acceptable range of yarn count and colour deviation across successive production runs of bleached or dyed linen. Without this designated band, slight shifts in water temperature or chemical concentration would cause mill rejections of entire linen shipments.
The boundaries of this range are agreed between the buyer and the spinner before spinning begins.
Mill Application
Mill technicians monitor yarn consistency by sampling the output at predetermined intervals during wet spinning. If the yarn properties drift outside the batch tolerance window, the spinning frame settings are adjusted or the batch is segregated for separate finishing. This active tracking prevents yarn unevenness from appearing as barre or banding in the woven linen cloth.
Continuous testing ensures that the final cloth meets the buyer’s quality guidelines. Such monitoring is performed at the start of each shift to detect early deviations before they accumulate into large-scale defects.
Boundary Parameter
Contractual penalties or complete batch rejections occur when yarn measurements fall outside these limits. The window loses its validity if the mill changes the raw flax source or uses a different bleaching agent during the run. This restriction protects the weaver from unpredictable shrinkage during high-temperature finishing processes.
It ensures the integrity of the long-term production contracts.
