Yarn count system for different fiber varies from fiber to fiber. Yarn number varies and it differs according to the kind of fibre. Many yarns use for weaving and sewing threads are numbered by the cotton system. Spun yarn size refer to as count and expresses in terms of length per unit of weight. It is an indirect system. The finer the yarn, the larger the number. The count is based on the number of hanks (1 hank is 840 yards) in 1 pound of yarn. In this system the unit of weight remains constant.
Count = length / one pound.
Count = No of hanks x 840 yards / one pound.
Yarn Count System for different fiber varies as
Denier: Filament yarn size is dependently part on the size of the holes in the spinneret and partly on the rate at which the solution is pumped through the spinneret and rate at which it is withdrawn.
The size of the filament yarns is determined as denier, which is expressed in terms of weight per unit length. If 9000 meters of yarn weigh 1 gm it is then 1 denier. In this system, the unit of length remains constant. The finer the yarn, the smaller the number.
Denier = weight of yarns in gms/9000 mts.
1 denier = 9000 mts weigh 1gm
Tex system: The international organization for standardization has adopted the Tex system, which determines the yarn count or number in the same way for all fibre yarns and uses metric units.
Tex = weight in gms/100 mts of yarn.