For worsted spining, ~40 fibers in the yarn cross-section is considered a commercial minimum. If the wool fiber density is 1.30 g/cm 3 , what is the minimum wool fiber diameter (micron) and metric count (Nm) required for spinning 80 Nm worsted yarn? 已知正常精纺纱线成纱要求单纱截面中纤维根数≥40根,羊纤维密度为1.30 g/cm 3 ,若纺80纱,问纤维至少需为多少?相当于羊纤维的细度为多少μm ?