Yarn count and yarn numbering system

Definition
The count of a yarn is a numerical expression which defines its fineness. It is also called as yarn number or liner density. It is also called as yarn diameter.
The fineness of yarn cannot be expressed easily inter-mesh of diameter as in case of wires or rods. The instrument such as micrometer cannot be used to determine the diameter of yarn. Therefore special methods are used to determine the fineness or coarseness of yarn.

System of yarn numbering

According to the definition given by the textile institute count is a number indicating the mass per unit length or the length per unit mass of yarn. Several systems and unit are used for expressing the yarn number.

Indirect system of yarn numbering

In this system:

1. The count is the number of units of length per unit of weight of yarn.
2. Higher the count finer is the yarn.
3. This system is generally used for cotton, woolen, worsted and linen yarn.

Merits of yarn numbering system

1. The weight of fabric can be calculated easily.
2. The threads per inch are directly proportional to the square root of the yarn count and they can be easily calculated.

Disadvantages of indirect of yarn numbering system

1. The count does not express the size of the yarn directly.
2. When the component threads are of different units, it is difficult to calculate the resultant count of folded yarn.

Direct system of yarn numbering

In this system the count of yarn is the number of units of weights per unit length of yarn. This system is used for jute and silk yarn.
Advantages of direct of yarn numbering system

1. The count directly expressed the size of the yarn.
2. The resultant count of the folded yarn can be easily calculated.

Demerit of direct of yarn numbering system
1. It is difficult to calculate the weight of the fabric.

Universal system
Tex system of yarn numbering is called as universal system. This is a direct system of yarn numbering. This system is applicable to yarn made from natural as well as synthetic fibers.
The merits and demerits as applicable like direct system of yarn numbering.

Units of length and weight in counting system

Indirect system

S.No.	Name of system	Weight unit	Length unit
1	Cotton English	1 Lb	Hank of 840 yard.
2	Cotton French	½ kg	Hank of 1000meters.
3	Cotton metric	1kg	Hank of 1000meters.
4	Spun silk	1 Lb	Hank of 840 yard.
5	Linen	1Lb	Lea of 300 yard.
6	Worsted	1Lb	Hank of 560 yard.
7	Woolen	1 Lb	Leaf of 300 yard.

Direct system:-

S.No.	Name of system	Weight unit	Length unit
1	Silk, Nylon	0.05grams	450meters
2	Jute, Hemp	1Lb	14,400yard.
3	Tex	1 grams	1000meters
4	Denier	1 grams	9000meters

Definitions of count in different system

1. Cotton English count (NE) / British count:

2. French count (NF):

3. Metric count (Nm):

Tex: It is defined as