Evaluating Linear Density Uniformity in Wet Spun Flax Sliver Lots
Evaluating wet-spun flax sliver linear density requires combining ten-metre cut-and-weigh gravimetric tests with conditioned capacitance spectrogram analysis.
ISO 6741 Moisture Regain Allowance
Commercial Weight Determination
Standardized protocols for calculating the mass of textile fibres ensure that trade between flax producers and spinning mills remains equitable. The iso 6741 moisture regain allowance provides the specific percentage added to the oven dry mass of linen to determine its invoiced weight. Since raw flax is hygroscopic, its physical weight varies with environmental humidity.
This standard fixes the conventional regain at 12 percent for flax yarns.
Laboratory Procedure
Drying a representative sample until it reaches a constant mass forms the basis of the test. Samples undergo heating in a ventilated oven at 105 degrees Celsius. The resulting dry weight is the baseline for the calculation.
Applying the iso 6741 moisture regain allowance requires adding the agreed percentage to this anhydrous mass. This step removes the volatility of ambient water content from the commercial transaction. Accurate weighing requires high precision scales and calibrated drying equipment.
Contractual Application
Buyers and sellers use these values to settle accounts for large shipments of wet spun yarn. Discrepancies in weight often occur when containers travel between humid coastal ports and dry inland mills. The iso 6741 moisture regain allowance acts as the legal reference point for resolving such differences in delivered mass.
It applies strictly to the fibre itself and excludes the weight of packaging materials or paper cones. Final settlement documents must cite the regain value used to arrive at the net weight for the invoice.