Yarn Counting Systems

The Yarn Count

The yarn count expresses the thickness of the yarn, and must be known before calculating the quantity of yarns for a known length of fabric. The yarn count number indicates the length of yarn in relation to the weight.

Three systems of yarn count are currently in use:

Fixed weight; the fixed length and the Tex systems. The foxed weight can be used with British and American weights and systems. The fixed length system and the Tex system are based on metric weights and measures.


1: The fixed weight system

This most popular system in the Textile Ind. Cotton Count (Ne) is used very widely.
The fixed weight yarn count system is used for numbering spun yarns of Cotton, Linen and Silk.

It is based on the length of the yarn per lb. weight.

The greater the length of the yarn weighing 1 lb., the finer it is, and the higher the count number.

The count number gives the number of unit lengths, I.E.: skeins, hanks, etc, in 1 lb.;.

E.g.: 10 hanks of cotton is abbreviated to 10’s cotton.

12 skeins Yorkshire woolen spun is abbreviated to 12’s Y.sk.

The unit length of 1’s count (i.e.: 1 unit count of 1 lb weight) varies with different fibres and spinning systems.

Wool:
Woolen spun:
Galashiels: cut (unit length) 200yards
(ie: 1’s wool has 200 yards per pound, 10’s has 2000 yards per lb., etc

Yorkshire : skein 256 yards

West of England: hank 320 yards
American (Philadelphia): cut 300 yards

Worsted Spun:
English and American hank 560 yards

Linen: lea 300 yards (ie: 1 lea linen has 300 yards, a 5 lea linen has 1500 yards)

Cotton: hank 840 yards

Spun Silk: hank 840 yards


Plied Yarns:


When a yarn is plied, that is, when two yarns of identical count are twisted together, the yarn is twice as thick, and therefore the length of yarn per lb is halved. The numbering of the yarn states both the count of the single component and the number of components that make up the ply.
E.g.: 2/10’s cotton; the length of this yarn would be 10 x 840 divided by 2 = 4200 yards per lb.

If the cotton yarn is plied, it is noted like this:

10/2 cotton. This means that 2 threads of #10 cotton singles spun at 8,400 yards/lb have been twisted together to give 4,200 yards/lb of 2 ply yarn.
The first number is the size of the singles yarn, the 2 gives the number of plies.
So... 10/4 cotton would be 4 threads of #10 cotton twisted together to give 2,100 yards/lb.

It can be seen from the table below that a 2/20 yarn varies greatly in length depending on whether it was measured as cotton, linen, wool, or worsted.

2/20’s cotton 8400 yds per lb 20s = 59 Tex
2/20’s linen 3000 yds per lb 20s linen = 166 Tex
2/20’s wool 2560 yds per lb 20s Wool = 195 Tex
2/20’s worsted 5600 yds per lb 20s Worsted = 89 Tex

NM :
NM stands for number of meters and is based on the number of meters in one gram of yarn. The NM designation would be noted either before or after a number indication the number of meters in 1 gram of yarn: NM 10 or 10 NM meaning there are 10 meters of yarn per gram. Plied yarn would be marked NM 2/10 with the first number indicating the number of plies and the second number giving the meters per gram.

Linen:

Flax fibers undergo a name change when they are spun and become linen. The unit of measurement for linen yarns is the lea and 300 yards per 1lb of fiber = 1 lea.

Linen Lea = Ne x 2.8 = (1661 / Tex) = (14,950 / Denier)

Silk:

In the English system, spun silk count is based on 840 yards per 1 lb of fiber.
#1 silk is 840 yards/lb
#2 silk is 1680 yards/lb
#3 silk is 2520 yards/lb
#10 silk is 8,400 yards/lb.
#20 silk is 16,800 yards/lb.

While the silk yarns may have multiple plies and skeins may be marked with the number of plies, the size number will always remain the same. So a #10 silk yarn will always have 8,400 yarns no matter how many plies went into making that yarn.

Calculating Cotton, Linen, and Silk Yarn Counts:

The formula for calculating the count of cotton, linen, and silk yarns is the same as those for woolens and worsteds:

Number of yards divided by weight times 16 oz (454 grams) times the number of plies divided by the FWS factor for the specific fiber equals Count.

The FWS factors are:
1. Cotton – 840
2. Linen – 300
3. Silk – 840



2. The fixed length system

This system in used to number continuous filament yarns, ie: reeled silk and man-made extruded yarns such as rayon.
It is based on a fixed yarn length to a variable weight and is measured in deniers.

The denier count of a yarn states the weight in grams per 9000 meters.

The coarser the yarn, the higher the denier count number becomes.

Thus: 9000 meters of 30 denier yarn weighs 30 grams.

Ne = 5,315 / Den

3. The Tex system.

Tex is an internationally agreed system of yarn numbering that applies to all types of yarns, regardless of the method of production. It is easy to understand and define, for commercial purpose other systems are more used than this.

The Tex system is also based on the fixed length system. i.e: Weight per unit length.

The Tex count represents the weight in grams per 1 kilometer (1000 meters) of yarn.

For example, a yarn numbered 10 Tex weighs 10 grams per kilometer.
20 Tex means weight of yarn is 20 Gms per Kilometer.

The Tex number increases with the size of the yarn - more the Tex thicker is the yarn.

For labeling yarns an international code is followed as below :

The yarn count number is followed by the word "Tex". The term "folded" is used in preference to "plied" yarn when two or more yarns are twisted together, and the direction of the twist is included in the formation.

E.g.: R 40 Tex/ 2 S – two threads of 20 Tex are folded in an "S" direction, therefore the resultant count (R) will be 40 Tex because the weight is exactly doubled.

This is unlike other systems where the count of child yarn is mentioned and not the final count.

To convert English Cotton Count to Tex

Ne = 590.5 / Tex

Denier :
This is most popular numbering system under Fixed Length Methods and used widely for most of the Man Made Filaments and Fibres.

Denier is a measurement that is used to identify the fiber thickness of individual threads or filaments used in the creation of cloth, carpeting drapery material, and similar products.

Yet surprisingly, the concept of denier was originally applied mainly to natural fibers, such as silk and cotton. Over time, the unit of thickness for synthetic fibers such as rayon and nylon also came to be identified as denier.

From definition it is clear that Denier is 9 times the Tex so conversion formulae are

Denier = Tex * 9

Ne = 5315 / Denier

Estimating the yarn count

When the yarn count is not known, it can be established by measuring a length of 10, 50, or 100 metres, depending on the count you judge the yarn to be. This is best done on a swift ( a skein winder) set to a circumference of 1 meter. The hank is then weighed in grams. Eg, if 50 meters of yarn weighs 2 grams, 1000 meters will weigh 40 grams and the count is therefore 40 Tex.