Rationalization Of Yarn Numbering

Conversion of count from one system to another costs time and money and there is always the risk of a mistake. As the textile industry developed commercially and technically ,it become increasingly clear that was need to devise a system of yarn numbering which could be used by all concerned in the production and distribution of this urgent need did not lead to its speedy solution.Numerous discussion and conference have been held but it was mot until comparatively recently that a firm decision was taken .

The Tex System:   The yarn number or count in the Tex system is the weight in grams of 1 km of yarn.This system is therefore a direct system, simply defined and simple to use.Extension of the basic system are used in order to express the fineness is expressed in  ''millitex" that is the weight in milligram per kilometer  .Foe such intermediate products as slivers and coarse yarn structure likes cords,the count is expressed in  "Kilotex" that is the weight in kilograms per  kilometer or what amount to the same thing, grams per meter.

The adoption of the Tex system of yarn numbering will ,of course, be a slow process work and some headaches until everyone becomes familiar with it, but this short-term disadvantage will be more than compensated for in the future when the old system are merely of historical  interest.A number of yarn and fabric feature are used numerically,and in their calculation the present system are used.For example the twist factor for a cotton yarns indicates the degree of twist in the yarn and is related to the count turns per inch in the following way :

It is  immediately obvious that when the Tex system is used "Terns per Inch" Will no longer be a suitable way expressing twist and that metric length unit would be appropriate , say, "Terns per inch " .The twist factor will therefore be different.Further since the Tex system is a direct system and cotton system an indirect system,the from of the relationship between turns ,twist factor, and count will change:

 Numerical examples to illustrate this point will be given when twist testing is discused later in this chapter.I fabric technology the openness, or, more appropriately,the closeness of a fabric, is expressed by the 'cover' factor.The warp cover factor is given by:

Again it is apparent that the inch must be by a metric length unit and that (rot cotton count) will be a different value to {rot (Tex Count)} .The cover factor could become.

1. Tex = 590.5 / Cotton count

2. Tex = denier x 0.111

A few calculation will show that the equivalent tex yarn yarn number of a 'round' traditional count is usually far from round.For example, 32 s cotton count become 18.45 tex ,and 150 denier become 16.67 tex. It will be appreciated that when the tex system is used commercial,inconvenient number such as these must be avoided.The industry will be obliged to alter its present range of yarn thicknesses slightly and spin to convenient tex yarn numbers.When the change is made the opportunity arises for the introduction of a reduced range of yarn thicknesses,an idea which has been put forward before.

Tex	Cotton	Worsted
10	59.5	88.6
10.5	56.1	83.4
11	53.7	80.5
11.5	51.3	77.0
12	49.2	73.8
12.5	47.2	70.9
13	45.4	68.1
14	42.2	63.3
15	39.4	59.5
15	36.9	55.4
17	34.7	52.1
18	32.8	49.2
19	31.1	46.6
20	29.5	44.3
21	28.1	42.2
50	11.8	17.7
60	9.8	14.8
80	7.4	11.1
100	5.9	8.9