HS Classification between Flax Fibre and Made-Up Linen Goods
Classification between Chapter 53 flax and Chapter 63 made-up linen depends strictly on Section XI Note 7 edge finishing, sewing, and structural shape criteria.
Tex Density
Measurement Metric
Linear mass per unit length defines the universal metric for quantifying yarn thickness and sliver weight across modern textile production. Designated by international standards as grams per one thousand metres, tex density establishes a direct measurement scale where higher numerical values indicate heavier and coarser strands. Flax spinning mills apply this direct system alongside traditional linen wet-spun lea counts to standardize inventory and processing controls.
The system applies to drawing slivers, roving ribbons, combed tops and finished singles yarn, replacing convoluted inverse numbering schemes. Metric applicability ends when characterising non-linear properties like tensile elongation or raw bundle diameter.
Calculation Method
Mill testing laboratories determine yarn counts by conditioning skeins under standardized relative humidity before precision analytical weighing. Technicians wind a sample length of one hundred metres on a motorized wrap reel, transferring the skein directly to an electronic balance. Dividing the measured mass in grams by length in metres and multiplying by one thousand yields the exact tex density of the production lot.
In linen wet spinning, a lea count of sixty corresponds mathematically to approximately twenty-seven point six tex, whereas a coarse tow yarn of twenty lea equals eighty-three tex. Process adjustments on the spinning frame alter draft gears whenever daily weighings drift beyond specified commercial tolerances.
Specification Contract
Export sale contracts define linear tolerance ranges within plus or minus three percent of nominal yarn targets. Verifying lot tex density ensures downstream weaving facilities maintain specified cloth weights and warp tension levels during high-speed loom operation.