Representation Method, Conversion Relationship, Test Method of Yarn Fineness / Yarn Count: Tex, Den, Nm, Ne

Yarn fineness definition: The fineness of yarn is known as the count of yarn. Yarns for fabrics can be thick or thin, and this degree of thickness is usually expressed in counts (metric yarn counts, English yarn counts), but also tex and Denier. The higher the count, the finer the yarn, and the lower the count, the thicker the yarn.

The finer the yarn, the lighter and thinner the woven fabric is, the appearance is tight and detailed, smooth and soft, and uniform color, the lighter the processed garment is. The thicker the yarn, the heavier the fabric, the coarser the appearance of texture, and the stronger the fabric.

Yarn fineness not only affects the thickness and weight of garment fabrics but also affects the physical and mechanical properties of fabrics, such as strength, stretchability, elasticity, and abrasion resistance. In addition, the uniformity of yarn fineness also poses a certain influence on the appearance style and performance. If the fineness is not uniform, it will cause an uneven surface of fabric, uneven thickness, and bad smoothness. In short, the fineness of yarn must attract the attention of textile practitioners.

Representation Method, Conversion Relationship, Test Method of Yarn Fineness / Yarn Count

1 Yarn definition: single yarn and plied yarn

The yarn is the collective name of the single yarn and plied yarn. Many short fibers or filaments are arranged in an approximately parallel state and rotated and twisted in the axial direction to form a thin object with a certain strength and thickness called yarn, a single is called single yarn, and two or more single yarns twisted together, called plied yarn, or thread for short. According to the number of plied yarn, it can be divided into 2-plied yarn, 3-plied yarn, etc. More about yarn can read this article: Yarn Classification Guide: Raw Material, Process, Structure, Use

2 Representation method of yarn fineness: yarn count

In most cases, yarns are not perfectly round in cross-section, they are easily flattened, they have more hairy surfaces and they are not uniform in thickness, thus a direct measurement of the diameter is both time-consuming and inaccurate. The fineness of the yarn is difficult to measure directly with tools and the general diameter representation is only used in research. Usually, an indirect indicator is used to express the fineness of the yarn: yarn count. Yarn count can be rated through this tester.

There are various indirect indicators, such as tex, dtex, denier, metric count, English count, etc. In general, the legal unit of measurement for textile fiber and yarn fineness is the tex, dtex. Professionally, the fineness of yarn is expressed in two indirect indicators, namely the direct yarn numbering system and the indirect yarn numbering system.

The direct yarn numbering system includes tex and Denier

Define	Description
Tex = (G/L) * 1000 G is the mass of the yarn (g); L is the length of the yarn (m). Tex indicates the weight of 1000m of yarn at the convention moisture regain. Tex is the legal unit of measurement, 1tex = 10dtex. At present, the linear density of cotton yarn and cotton-type chemical fiber pure and blended yarn is often expressed in terms of tex.	The larger the value of the text, the thicker the yarn. For example, at convention moisture regain of 8.5%, there is a cotton yarn that weighs 18.2g for 1000m, so the yarn count is called 18.2tex. The plied yarn is equal to the single yarn tex multiplied by the ply number, such as 20tex*2 for a single is 20tex 2-plied yarn, and the count of the plied yarn is 40tex. When the text of a single yarn is different, the count of plied yarn is the sum of the tex number of single yarns, such as 20tex + 30tex, and the count of the plied yarn is 50tex.
Denier is simply called D D = (G/L) * 9000 G is the mass of the yarn (g); L is the length of the yarn (m). Denier indicates the mass of 9000m long fibers (or yarns) at the convention moisture regain. It is commonly used to indicate the fineness of chemical fiber filaments and silk.	The larger the value of Denier, the thicker the silk yarn. For example, a 9000m filament weighing 1g is called 1D and while weighing 100g is called 100D at the convention moisture regain. Natural fibers of raw silk are made of multiple cocoon silk merged, the thickness of each cocoon silk is not the same, so the merged raw silk thickness differences, commonly used two limit numbers to indicate, such as 20/22 denier, which means that there is a difference between 20 ~ 22 denier. Natural fibers of raw silk are made of multiple cocoon silk merged, the thickness of each cocoon silk is not the same, so the merged raw silk thickness differences, commonly used two limit numbers to indicate, such as 20/22 denier.

The indirect yarn numbering system includes metric count and English count

Define	Description
Metric count is abbreviated as Nm Nm = L/G G is the mass of the yarn (g); L is the length of the yarn (m). The metric count is an index of fineness using metric units of measurement. In the convention moisture regain, is expressed in terms of the length (m) that 1g of yarn has. The fineness of the wool yarn and wool-type chemical fiber (pure and blended) is often expressed in the metric count.	The higher the metric count, the finer the yarn. For example, if a combed wool yarn is 1 strand (50m long per strand), and the weight is 1.25g at convention moisture regain, the combed wool yarn is 50/1.25 = 40 metric counts. A plied yarn consisting of single yarns of the same count, e.g. 40Nm/2 means a 40Nm single plied yarn with a combined count of 20Nm. If the single-plied yarns have different counts, the counts of the single yarns are listed side by side and separated by a slash, e.g. 24/28.
English count for short Ne Ne = (L/G) * 840 L is the length of the yarn (yd) and G is the mass of the yarn (lb). English count is an index of fineness in English units of measurement. At convention moisture regain, how many times of 840 yards length of 1lb weight cotton fiber yarn, which is called how many English counts(S). At present, in cotton, viscose staple fiber blended with synthetic fibers are expressed in English counts (S).	The higher the count value, the finer the yarn. The application and expression are similar to metric counts, such as 32s, 40s, 32s/2, 40s/3, etc. For example, if a cotton yarn weighs 1lb and has a length of 32 times 840 yards measured at convention moisture regain, the yarn is called 32s. The plied yarn is expressed in the same way as the metric count. It is important to note that the specified lengths are different for different types of yarn.

Note:

The formula for calculating the count of the plied yarn is as follows

Metric convention moisture regain is 8.5%. English convention moisture regain is 9.89%. Moisture regain, which is the percentage of yarn water weight to yarn dry weight, i.e.

Moisture regain = (yarn wet weight – yarn dry weight) / yarn dry weight * 100%.

Since yarns, especially natural yarns, have good moisture absorption, the moisture regain varies with weight, and the actual moisture regain of various yarns varies with temperature and humidity conditions. To compare the moisture absorption capacity of various yarns, they are often placed in a uniform standard atmospheric condition and after staying for a certain period, their moisture regain reaches a stable value, which is then called the moisture regain in the standard atmospheric condition.

However, in trade costing, the yarn is not in standard condition, and the actual moisture regain of the same material in the standard condition is also related to the quality of the fiber itself and the impurity rate, etc. For fair measurement and valuation, there is recognized moisture regain, which is called convention moisture regain. It is close to the standard moisture regain, but not the standard conditions of moisture regain.

The weight of tex is the weight at the convention moisture regain. For different types of fiber, the conventional moisture regain is also different, such as cotton yarn 8.5% (English 9.89%), silk 11%, acrylic 2%, viscose 13%, etc. More conventional moisture regain can be found in the relevant manual. In practice, the material is often dried in the laboratory oven/incubator first and then calculated as dry weight * (1 + convention moisture regain) to obtain the convention weight.

3 Conversion relation of yarn fineness index

In the customary, the fineness of cotton and linen fiber is expressed by the metric count Nm, the fineness of wool fiber is expressed by the diameter and quality count, the fineness of silk, chemical fiber is expressed by denier, the fineness of cotton yarn is expressed by English count Ne. The conversion relationship between them is shown in the table below

Index	conversion formula
Ne and tex	Tex = (590.54/Ne) * (100 + metric convention moisture regain) or = (590.54/Ne) * (100 + English convention moisture regain)
Nm and tex	tex = 1000/Nm
Denier and tex	1D = (1/9)tex = 1.1dtex (1tex = 10dtex)

For example, in 150D filament yarn, the metric count is 60Nm, and tex is 16.67tex. Pure cotton yarn is 18.2tex, by conversion, we can know that the yarn is 32 metric count.

Since the English convention moisture regains of cotton yarn is 9.89% and the metric convention moisture regain of cotton yarn in the tex system is 8.5%, the factor 590.5 should be changed to 583.1 when converting the English count to metric count. In addition, there is no difference in the conventional moisture regain for pure chemical fiber yarns, so the effect of moisture regain is not considered and its conversion constant is 590.5

Tex versus other indicators

Ne and tex

Ne tex	120 5	115 5.1	110 5.3	105 5.6	100 5.9	90 6.6	86 6.9	80 7.5	60 10	57 10.5	50 12
Ne tex	42 14	40 14.5	36 16.5	34 17.5	32 18.5	30 19.5	28 21	24 25	21 28	20 30	18 33
Ne tex	14 42	10 59	8 74	6 100	5 120	2 300	1 590

Nm and tex

Nm tex	200 5	180 5.6	140 7.1	125 8	120 8.3	100 10	90 11.1	84 11.9	77 13	72 14	69 14.5
Nm tex	60 16.7	56 18	50 20	48 20.8	40 25	38 26.3	30 33	20 50	13 77	10 100	5 200

D and tex

D tex	1 1.1	3 3.3	5 5.5	7 7.8	10 11	12 13	15 17	18 20	20 22	28 31	30 33
D tex	20 22	35 39	40 44	45 50	50 56	56 62	70 78	75 82.5	100 110	150 167	300 330

Fineness parameters of commonly yarns

Yarn type	Commonly used fineness parameters
Cotton yarn	12tex, 14.5tex, 18.5tex, 21tex, 28tex, 33tex…
Woolen yarn	10tex, 11.8tex, 12.3tex, 15.5tex…
Silk	4.76tex, 5.9tex, 7.14tex…
Mulberry silk	14.3/16.5dtex, 22/24.2dtex, 30.8/33dtex, 38.5dtex, 77dtex…
Chemical fiber filament	56dtex, 66dtex, 82.5dtex, 110dtex, 167dtex…

4 Test method of yarn fineness/yarn count

Test standard: ISO 2060
Textiles – Yarn from packages – Determination of linear density (mass per unit length) by the skein method

Testing instrument: Wrap Reel meter, and yarn count tester