Flax Fiber Yield Losses during Wet Spinning Attenuation
Wet spinning attenuation loses 5% to 16% dry fiber mass through pectin dissolution and short fiber detachment, requiring bone-dry mass audit reconciliation.
Yarn Count Metric Number
Metric Density
The metric number for yarn count establishes the mass length ratio applied across flax spinning mills in Zhejiang to determine linear density per unit weight. A higher numerical designation denotes a finer filament strand drawn from raw flax straw, whereas lower digits designate coarse tow yarn intended for heavy canvas. This linear value governs drafting rollers on ring frames during wet spinning operations, where moisture content directly influences twist angle and breakage tension.
Inspectors record this numerical grade on the mill production docket before moving bobbins to the sizing department for warp preparation.
Count Conversion
Direct numbering systems rely on the fixed mass method, where grams per kilometre dictate the thickness designation of linen roving. Indirect numbering systems reverse this logic by calculating the length contained within a fixed mass of five hundred grams, thereby producing an inverse relationship between the resulting integer and actual strand thickness. Mill technicians calculate Nm by dividing the total length in metres by the mass in grams, yielding a standard metric figure that appears on export compliance documents.
Export documents require this specific metric value to satisfy customs declarations and verify that imported flax yarns match buyer specifications stipulated in sales contracts.
Quality Threshold
Laboratory technicians test conditioned skeins in standard atmospheric chambers to verify that actual count metric numbers fall within established tolerance limits defined by the trade agreement. Variations exceeding five percent above or below the contractual target trigger an automatic rejection of the spinning lot at the finishing stage. Buyers establish acceptance criteria based on tensile strength per unit tex, while individual mills maintain tighter internal tolerances to minimize yarn breakage during high speed weaving on air jet looms.
Moisture regain variations during wet spinning distort the measured metric number if conditioned testing fails to follow strict temperature protocols.