Identification method of gram weight and count of knitted fabric
Count is the number of lengths of 840 yards in a pound (454 grams) cotton yarn. The larger the count, the finer the yarn. For example, 48S is thinner than 23. Gram weight refers to the number of grams per square meter of fabric weight. Generally speaking, the larger the number of yarns of the same quality, the greater the gram weight. The gram weight of blank cloth and the gram weight of finished products may be greatly different from the actual ones if they are calculated by formula, for two main reasons. Embryo cloth can be calculated by formula, and the more similar the conditions are, the more accurate the results will be. Because the weaving changes to the physical nature, the cloth is processed from embryo cloth to finished cloth, which goes through multiple processes of dyeing and finishing. The process involves various types of machinery, processes and so on, forming different enterprises have different specifications and standards, so each enterprise has its own standard for the conversion of the gram weight of the blank cloth and the gram weight of the finished product.
The gram weight of the grey cloth is converted from the gram weight of the finished product
How to establish the conversion formula? It is suggested to collect the results from the previous blank cloth to the finished cloth, and then use the results of the most computer screening 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
Weight coefficient of cloth embryo: Plain 92% / double bead 88% / double garment 89% / single bead 93% / single garment 89% / rack plain 100% / scarf 106%/ double 88% / rack rib 91% / rib 83% rack lamp 92% / lamp core 87%.
(1) Fabric weight: refers to the weight of fabric per unit area, generally expressed in grams per square meter (g/m2). The simplest calculation in business.
For example: cotton fabric is generally in the range of 70 ~ 250 g/m2;
Vertine (combed) wool fabric weight about 185 g/m2;
Thick tweed (coarse comb) is about 280g/m2;
Thin silk fabrics are generally between 20 ~ 100 g/m2.
Fabric weight is also one of the character indexes to evaluate the physical properties of fabric, which is more important for wool fabric. It is stipulated in the Ministry standard of combed fabric and wooly chemical fiber fabric that the weight of square meters should not exceed the allowable tolerance (stipulated as 5%), which is classified as first-class products. More than 5% but not more than 7%, is second class.
(2) According to the "Ministry Standard" calculation method (moisture return factor shall be deducted) :
In the formula: GK -- weight of square meter under normal moisture return rate (g/m2) GO -- dry weight of sample (g) WK -- normal moisture return rate of sample (%) L -- length of sample (cm) B -- width of sample (cm) Fixed moisture return rate (WK) of common yarns is summarized as follows: cotton yarn: 8.5% worsted yarn: 16% carded yarn: 15% polyester/cotton (65/35): 3.2%.
(3) The approximate calculation method of the weight of square meters according to the fabric structure factors:
Where: NtT -- Tex number of warp (numbered) NTw -- Tex number of weft (numbered) PT -- warp density (root /10cm) PW -- weft density (root /10cm)
This calculation formula is approximate and does not take into account yarn bending, elongation and weight changes in the fabric during processing. (Note: Tex number (number) refers to the weight (g) of 1000 meters of yarn at the common moisture return rate.) .
Dry weight of one square meter cotton cloth without pulp:
Where: G -- pulp free drying weight of one square meter cotton cloth (grams);
Gj -- the dry weight of the warp of one square meter of cotton cloth (grams);
Gw -- dry weight of weft yarn in one square meter of cotton cloth (grams);
Pj -- Warp density of cotton (root / 10cm)
Pw - cotton weft density (root /10 cm);
gj -- standard dry weight of warp spun (g /100 m);
gw -- standard dry weight of weft spun out (g /100 m);
Fj -- total warp flaring rate;
aj -- warp shrinkage rate;
Sjz - total warp elongation;
aw -- weft shrinkage rate.
1. Warp and weft yarn spinning standard dry weight (g /100) = metric number * 0.92166/10 or =53.74 / British number
2. The weight of strands shall be calculated according to the weight after merging.
3, the total elongation of warp yarn: sizing single yarn is calculated at 1.2% (winding, warping calculated at 0.5%, sizing calculated at 0.7%). For Line 10 and 2 of Sheung Shui Strand, 0.3% shall be applied and 0.7% shall be applied for line 10 and 2 and above.
4, indirect filling yarn elongation is small, can be omitted.
5, warp total flying rate: coarse size (branch) fabric according to 1.2%; Medium (branch) plain fabric by 0.6%, twill fabric by 0.9%; Fine size (branch) fabric according to 0.8%; Thread fabric is measured by 0.6%.
6. The total warp elongation, the total warp flaring rate and the warp and weft shrinkage rate are the basis for calculating the weight of a square meter fabric, not the prescribed index. The simple method for evaluating the price and collar yarn in the workshop: 100 meters of warp = warp density/count * gate width *0.0065 100 meters of weft = weft density/count * gate width *0.0065 (for artisan) warp for 100 meters = (warp number * total warp number/(1-warp shrinkage)) /10000*1.01 weft for 100 meters = weft number * weft density *3.937* (sley width + refilament) /100000*1.003 refilament -- elastic yarn takes 12cm, This formula is widely used in the convenient calculation of sales staff (also not the invention of musical notes), the principle is correct, the calculation is simple, the error is inevitable (your so-called 101g/m2, juedui correct? No, it's just jingque.) 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 direction:
a. Convert imperial density to metric density by (latitude) density /2.54--------
b. Coefficient 1.1------- is a comprehensive consideration of warp (weft) shrinkage and warp (weft) yarn loss of about 10%. Although there is a deviation, as a quick and convenient calculation, there is no major problem.
c.59/ yarn count ------- is to convert the British yarn count into the metric special number, which is a combination of conversion factors such as 583.1 cotton and 590.5 polyester, etc. The coefficient of 590 is adopted. Although there are errors, there is no major problem.
d. I have not listed all the specific unit base conversion involved. I believe you should have this basic skill.
To sum up: Warp a * b * c + weft a * b * c = precision + weft density)*1.1*59/(2.54* yarn)= grey cloth square meter gram weight fabric cost accounting data yarn per meter = (warp density + weft density) X0.065X finished door width X1.01
For example: 45s T/C*45sT/C 110*70 58/59 data-index-1668664415214="2280" data-textnode-notemoji-index-1668664415214="2280" class="character" style="margin: 0px; padding: 0px;" >" polyester cotton rice (yarn price: 26000 yuan/ton) 100 meters yarn amount = (110+70) / 45X0.65X59X1.01 =15.5KG/ 100 meters per meter yarn amount of 155G/M. The yarn dyeing fee is 8000 yuan/ton, then the quotation 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 post-pass treatment. The common textile calculation formula is divided into two kinds: the calculation formula of fixed length system and the calculation formula of fixed weight system.
1. Calculation formula of fixed length system:
(1), Denier (D) =g/L*9000, where g is the weight of the silk thread (grams),L is the length of the silk thread (meters)
(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 of the silk thread (grams),L is the length of the silk thread (meters). The calculation formula for fixed weight:
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. Choose the conversion formula:
(1) The conversion formula of metric count (N) and Denier (D) =9000/N
(2) The conversion formula of English count (S) and Denier (D) =5315/S
(3) The conversion formula of dtex and tex is 1tex=10dtex
(4) The conversion formula of tex and Denier (D) :tex=D/9
(5) The conversion formula of tex and English count (S) :tex=K/S K value: pure cotton yarn K=583.1 pure chemical fiber K=590.5 polyester cotton yarn K=587.6 cotton viscose yarn (75:25)K=584.8 dimensional cotton yarn (50:50)K=587.0
(6) Conversion formula between tex and metric number (N) :tex=1000/N
(7) Conversion formula of dtex and Dannier :dtex=10D/9
(8) The conversion formula of dtex and English branch (S) is as follows: dtex=10K/S K value: pure cotton yarn K=583.1 pure chemical fiber K=590.5 polyester cotton yarn K=587.6 cotton viscose yarn (75:25)K=584.8 dimensional cotton yarn (50:50)K=587.0 9) Conversion formula between dtex and metric system (N) :dtex=10000/N
(10) The conversion formula between metric centimeter (cm) and British inch (inch) is :1inch=2.54cm
(11) The conversion formula of metric meters (M) and British yards (yd) :1 yard =0.9144 meters
(12) The conversion formula of the gram weight of square meters (g/m2) and m/m of satin is as follows :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