Calculating Plain Linen Target Weight from Yarn Count
Target linen weight equals yarn tex multiplied by thread density, adjusted for warp size, crimp, wet process mass loss, and area shrinkage factors.
Lea
Yarn Measure
Linear density in wet-spun and dry-spun flax manufacturing is traditionally expressed through an indirect length-per-mass unit defined by the number of 300-yard skeins contained in one avoirdupois pound. A standard linen lea count indicates fineness where higher numerical values correspond to finer yarn diameters and lower values denote coarse roves. In international flax procurement and Chinese spinning mills, this numbering system governs product classification across long line flax and short tow stock.
The metric boundary stops at synthetic filament blends and rotor-spun blended yarns, which typically transition to the metric count or direct Tex system.
Count Determination
Laboratory verification of yarn fineness requires skein reeling under regulated tension followed by conditioning in a standard atmosphere before analytical weighing. Laboratory technicians wind a predetermined length of yarn onto a wrap reel to produce lea skeins, verifying the exact linear mass on an electronic balance calibrated to decimal fractions of a gram. The calculated count is cross-referenced against target tolerances specified in mill spinning orders and international buyer contracts.
Deviation beyond contracted yarn count tolerances triggers automated adjustments to drafting zone gear ratios on wet spinning frames to correct sliver mass delivery. Mill test certificates document both the mean lea count and the coefficient of variation across multiple spindle positions to verify spinning stability across the entire lot. When the measured skein weight falls below tolerance, yarn strength diminishes proportionately, increasing breakage rates during subsequent warp preparation.
Spinning Control
Mill operational schedules use nominal count designations to allocate combed sliver assortments to specific ring spinning frames. Production planning boards specify the target lea along with flyer speed, ring rail traverse rate, and trough water temperature.