Metric Fibre Number Claims and the Test Method behind Them
Metric fibre number claims require ISO 2370 gravimetric verification because airflow instruments skew up to fifteen percent across retting types and moisture regains.
Acceptance Sampling
Quality Protocol
Statistical quality control procedure that determines whether a batch of raw material or yarn meets contract specifications based on the inspection of a drawn subset of units. Applying acceptance sampling protects the spinning mill from high-variability flax fiber shipments. In practice, this procedure defines the number of bales or packages required for testing and the threshold of defects allowed before the entire shipment is returned to the supplier.
Operating Curve
Operational plans define the probability of accepting a consignment under varying levels of batch quality. When buyers apply acceptance sampling to linen yarn shipments, they balance the producer risk of rejecting a compliant batch against the consumer risk of accepting a substandard one. Mill laboratories perform these evaluations by extracting randomized test specimens during the unpacking stage.
A typical plan might draw ten packages from a lot of one thousand, allowing only one package to fall below the minimum tensile threshold. If more than one specimen fails, the consignment is rejected.
Rejection Risk
Total manual inspection of every single package or bale of raw flax remains cost-prohibitive. A statistical compromise keeps laboratory costs low while providing a known level of quality assurance. The model ceases to be valid if the samples are not drawn from randomized strata within the consignment.