# Identification of Fabrics

Jul. 30, 2020
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Identification method of gram weight and count of knitted fabrics

Count is the number of 840 yards of cotton yarn that weighs a pound (454 grams).The larger the count, the thinner the yarn.For example, 48S is thinner than 23.Gram weight refers to the weight in grams per square meter of fabric.Generally speaking, the greater the number of yarns of the same quality, the greater the gram weight.Grey cloth gram weight and gram weight conversion products, such as in formula, and actual may have very big deviation, the main reason is divided into two aspects, embryo layout can use the formula to calculate, as long as the condition is more near, the result more accurate, for weaving is a physical change, and by grey fabric processing for the finished fabric, after dyeing and finishing multiple processes, fabric after physical and chemical change, variable increase, involving various types of machinery, during working procedure, and so on, form each enterprise has different specifications, so the fabric gram weight and finished product gram conversion, every enterprise has its standards.

The gram weight of grey cloth is converted to the gram weight of finished product

How to set up a reduction formula?It is suggested to collect the results from the blank cloth to the finished cloth, and then use the computer to select the most results as the standard, and then evaluate its practicability according to the production situation of the enterprise, and then formulate the conversion formula.

Example reference :(general cloth, general dyeing and finishing process) embryo weight == order product weight x embryo weight coefficient

Cloth like embryo weight coefficient: plain weave 92% / double bead 88% / double position clothes 89% / single bead 93% / single position clothes 89% / pull plain weave 100% / wool towel 106%/ double side 88% / pull rib 91% / pull rib 83% Pull rib 92% / lamp core 87%.

1, grey cloth weight: refers to the weight per unit area of the fabric, generally expressed in grams per square meter (g/m2).The simplest calculation in business.

For example, cotton fabrics are generally in the range of 70 ~ 250 g/m2;

The weight of Vaseline (combed) wool fabric is about 185 g/m2.

Thick tweed (coarse comb) is about 280g/m2;

Thin silk fabrics are generally between 20 ~ 100 g/m2.

Grey cloth weight is also one of the moral character index that examines fabric physical performance, this pays more attention to wool fabric.It is stipulated in the "Ministry award" standard of worsted fabric and woolen type chemical fiber fabric that the weight of square meter is too light to exceed the allowable tolerance (the stipulation is 5%), and it is classified as first-class goods.More than 5% but less than 7% is second class.

(2) According to the calculation method of the Ministry standards (moisture regain factor should be deducted) :

Where: GK -- square meter weight (g/m2) GO -- sample dry weight (g) WK -- sample common moisture regain (%) L -- sample length (cm) B -- Sample width (cm) The constant moisture regain (WK) of commonly used yarns is summarized as follows: cotton yarn: 8.5% worsted yarn: 16% carded yarn: 15% polyester/cotton yarn (65/35): 3.2%.

(3) Calculation method for approximate weight in square meters based on fabric structure factors:

Where: NtT -- warp Tex number (digit) NTw -- weft Tex number (digit) PT -- warp density (root /10cm) PW -- weft density (root /10cm).

This calculation formula is an approximation and does not take into account the bending, elongation and weight change of the yarn during processing.(Note: The Tex number refers to the weight (g) of the yarn 1000 m long at a common determination of moisture regain.).

One square meter cotton cloth without pulp drying weight:

Where: G -- dry weight (G) of cotton cloth without pulp of one square meter;

Gj -- dry weight of warp yarn of cotton cloth of one square meter (gram);

Gw -- dry weft weight of cotton cloth of one square meter (g);

Pj -- Warp density of cotton cloth (root / 10cm)

Pw -- weft density of cotton cloth (root /10 cm);

Gj -- standard dry weight of warp spun (g / 100m);

Gw -- Weft spun out standard dry weight (g / 100m);

Fj -- total flying rate of warp yarn;

Aj -- warp shrinkage;

Sjz -- total warp elongation;

Aw - filling shrinkage.

Among them:

1. Standard dry weight (g /100) of weft and warp yarn = metric number * 0.92166/10 or =53.74 / inch count

2. The weight of strand is calculated according to the weight after merging.

3. Total warp elongation: sizing single yarn is calculated at 1.2% (including winding and warping calculated at 0.5%, sizing at 0.7%).The shangshui ply line no. 10 and No. 2 shall be calculated as 0.3% and above no. 10 and No. 2 shall be calculated as 0.7%.

4. Indirect weft elongation is small and may be omitted.

5. Total flying rate of warp yarn: coarse (branch) fabric is calculated at 1.2%;Medium (branch) plain weave fabrics by 0.6%, twill fabrics by 0.9%;Fine (branch) fabrics by 0.8%;Yarn fabrics are counted at 0.6%.

6. The total elongation of warp yarn, the total flying rate of warp yarn and the shrinkage rate of warp and weft yarn are the basis for calculating the fabric weight of one square meter, not the specified index.A simple method for estimating the price and workshop collar yarns: 100 m warp = warp density/count * portal width *0.0065 100 m weft = filling density/count * portal width *0.0065(engineer) hundreds of meters with warp = (warp number * total number of the root/(1 -) of shrinkage rate) / 10000 * 101 m with weft weft weft density number * * * 3.937 = (reed space + waste) / 100000 * 1.003 waste - 12 cm, stretch yarn take tome yarn 8 cm this formula is widely used for the sales staff of convenient calculation (not note) invention, principle of right, simple calculation, error is inevitable, you so-called 101 g/m2, you absolutely right?Definitely not, just to be more precise).Grey square metre gram weight = (end spacing + weft density) * 1.1 * 59 / (2.54 * yarn count) = end spacing * 1.1 * 59 / (2.54 * yarn count) + weft density * 1.1 * 59 / (2.54 * yarn count).

Longitude and latitude:

A. Warp (weft) density /2.54-- convert inch density to metric density

B. Coefficient 1.1-- considering the warp (weft) shrinkage rate and the warp (weft) yarn loss, it is about 10%. Although there is a deviation, but as a quick and convenient calculation, it doesn't matter.

C.59/ yarn count -- it is to convert the inch yarn count to the metric special number, and it is to combine the conversion coefficient of cotton 583.1, polyester 590.5, etc., and take the coefficient of 590, although there is an error, there is no serious harm.

D. I don't have specific examples of unit conversion involved. I believe you have the basic skills.

To sum up: Warp A * b * C + zonal A * b * C = precision + weft)*1.1*59/(2.54* yarn)= grey fabric square meters gram weight fabric cost accounting data per meter = (warp + weft) X 0.065x finished product width X1.01

For example: 45sT/C *45sT/C 110*70 58/59" T/C (yarn price: 26000 yuan/ton) yarn quantity for 100m = (110+70) / 45x0.065x59x1.01 =15.5KG/ 100m yarn quantity for 155G/M.The yarn dyeing fee is 8000 yuan/ton, and the price per meter is 15.5x (2.6+0.8) = 5.27 yuan/meter, plus 3 yuan/meter for public payment, and 1.00 yuan/meter for aftertreatment. The calculation formulas commonly used for [conversion] textile are divided into two kinds: calculation formulas for fixed-length system and fixed-weight system.

1. Calculation formula of fixed length system:

(1) denier (D) =g/L*9000, where G is the weight (g) and L is the length (m) of the silk thread.

(2), Tex (number) [Tex (H)] : Tex = g/L of * 1000 g for yarn (or silk) weight (g), L the length of the yarn (or silk) (m)

(3) DTEX: DTEX =g/L*10000 where G is the weight (g) of the silk thread and L is the length (m) of the silk thread. Calculation formula of fixed weight is as follows:

Metric count (1), (N) : N = L/G which G for yarn (or silk) weight (G), L the length of the yarn (or silk) (m), (2), the imperial count (S) : S = L/(G * 840) which G is the weight of the silk thread (lb), L is the length of the thread (yards)

2. Select the conversion formula:

(1) The conversion formula between metric count (N) and Denier (D) =9000/N

(2) The conversion formula of the count of English system (S) and denier (D) =5315/S

(3) Conversion formula between DTEX and Tex: 1TEX = 10DTEX

(4) The conversion formula between Tex and Denier (D) : Tex =D/9

Tex =K/S Value: pure cotton yarn K=583.1 Pure chemical fiber K=590.5 poly-cotton yarn K=587.6 cotton viscose yarn (75:25)K=584.8 dimensional cotton yarn (50:50)K=587.0

(6) Tex and metric number (N) conversion formula: Tex =1000/N

(7) The conversion formula between DTEX and Denier (D) : DTEX =10D/9

Value of K: pure cotton yarn K=583.1 pure chemical fiber K=590.5 poly-cotton yarn K=587.6 cotton viscidity yarn (75:25)K=584.8 dimensional cotton yarn (50:50)K=587.0 9). Conversion formula of DTEX and metric count (N) : DTEX =10000/N

(10) the conversion formula between the metric centimeter (cm) and the inch (inch) :1inch=2.54cm

Conversion formula of metric meter (M) and British code (YD) :1 yard =0.9144 M

The conversion formula of silk and satin square gram weight (g/m2) and mu meter (m/m) :1m/m=4.3056g/m2

(13), the weight of the silk and the formula for converting pounds: pounds (lb) = silk weight per meter (g/m) * 0.9144 (m/yd) * (yd) / 453.6 (50 g/yd     