Views: 6 Author: Site Editor Publish Time: 2022-01-07 Origin: Site
1. Yarn consumption
Grey cloth is woven from warp and weft yarns. Knowing the amount of warp and weft per unit area of the grey fabric and the unit price of these yarns, the raw material price of the grey fabric can be calculated. Generally, you can know the amount of yarn used in the grey fabric according to the process sheet on the machine, or you can calculate the amount of yarn used by measuring the warp and weft density and yarn specifications according to the sample of the grey fabric. When measuring yarn specifications, both high-precision electronic balances and yarn properties are required. Measuring the length and quality of the warp and weft yarns can get the yarn titer. Through the combustion method, the basic properties of commonly used textile materials can be basically judged.
After receiving samples from customers, trading companies can obtain the calculation results of grey fabric prices with the help of textile mills. Trading companies can also preliminarily confirm product prices through calculations. Today, when small batches and multiple varieties are prevalent, the total amount of transactions per customer is not large. Calculating the price of finished products quickly for customers is a concrete manifestation of providing customers with high-quality services.
For example, if two synthetic fiber filaments are removed from a gray cloth sample, the mass of the two chemical fibers with a length of 12 cm is measured to be 0.0039 grams, then the yarn size is:
After burning experiments, it was observed that the fiber emits white smoke when burning, and the residue after burning is a black hard substance. It can be preliminarily determined that the fiber is 166 tex polyester filament. When dyeing the grey fabric samples with acid dyes, disperse dyes and cationic dyes respectively, the properties of the grey fabric materials can also be further confirmed. The raw material with the deepest coloration of acid dyes at room temperature is nylon; the deepest coloration of cationic dyes is acrylic or cationic dyeable modified polyester; it can be clearly seen after 20 minutes of boiling under weak acid conditions that the color of the gray fabric to be tested is dyed by disperse dyes. Deepest. In actual production, after polyester-cotton blended yarn and polyester-viscose blended yarn are woven into fabrics, the whiteness of the grey fabric surface is different, and the polyester-viscose grey fabric is whiter. No matter what method is used to determine the basic properties of raw materials, it is necessary to listen to expert opinions in the final confirmation. It is easier to judge the basic properties of fiber raw materials by the finished product than by the grey fabric.
2. Weaving costs
When weaving woven fabric, the higher the weft density, the lower the weaving efficiency and the higher the weaving cost. The textile factory finally determines the weaving cost of the grey fabric according to the comprehensive consideration of raw material specifications, weft density, weaving efficiency, weaving difficulty and other factors. Usually the weaving fee given by the textile factory is the weaving price per centimeter of grey cloth. This price is often expressed by "shuttle" instead of "shuttle/cm". If the weft density on a certain grey fabric is 16 shuttles/cm, and the weft density on another grey fabric is 32 shuttles/cm, the weaving cost of the former is 50% lower than that of the latter when the weaving speed is the same. The more complex the fabric weave, the more difficult it is to weave. The weaving equipment of a certain factory is all wide-width air-jet looms, and the weaving price of plain weave polyester grey fabric with a weft density of 16 shuttles/cm is 0.018 yuan, so the fabric weaving processing fee is 1.8 yuan/m. And the price of the fabric per 100 shuttles is:
100 (shuttle) ÷ 16 (shuttle/cm) × 0.018 (yuan/cm) = 0.1125 (yuan)
3. Loss of raw materials
In the weaving process, the cloth edge must be cut off before the grey cloth is wound onto the cloth roll. If you use a finished product sample or a gray fabric sample as a sample to analyze the price composition of the gray fabric, you must consider the consumption of raw materials. Analyze the price of grey fabric with a sample of grey fabric. The consumption of selvage weaving yarn for chemical fiber and filament can be calculated at 1.5% of the total yarn used per unit area of grey fabric; grey fabrics made of chemical fiber and cellulose fiber blended yarn as raw materials are used for fabric weaving Yarn consumption can be calculated based on 2% of the total amount of yarn used per unit area of the grey fabric; the yarn consumption of cellulose fiber products can be calculated based on 2.5%-3% of the total amount of yarn used per unit area of the cellulose fiber product. When estimating the price of grey cloth with a sample of the finished product, the consumption of selvedge weaving yarn can also be increased appropriately.
4. Calculation example
Knowing that the price of 200D polyester low-stretch yarn is 12,000 yuan/ton, the price per kilogram is 12 yuan. When per ton of polyester low-elasticity yarn is covered with spandex yarn, 44 kilograms of spandex is required. The unit price of spandex is 90,000 yuan/ton, and the processing cost of spandex covered yarn is 500 yuan per ton. Then the unit price per kilogram of spandex coated yarn is:
90000 (yuan/ton) ÷ 1000 = 90 (yuan/kg)
90 (yuan/kg) × 44 (kg/ton) = 3960 (yuan/ton)
12000 (yuan/ton) + 3960 (yuan/ton) + 500 (yuan/ton) = 16460 (yuan/ton)
16460 (yuan/ton) ÷ 1000 (kg/ton) = 16.46 (yuan/kg)
Both the warp and weft of the grey fabric are (P200D + Sp40D), the warp density on the machine is 76 yarns per inch, and the weft density is 46 yarns per inch. The width of the upper machine is 81 inches. The raw material loss caused by trimming during weaving is 4% of the weight of the grey fabric. The spandex is calculated at 4% of the weight of the grey fabric. The manufacturing and processing fee for each 100 shuttles of the air-jet loom is 0.11 yuan. Q: What is the unit cost of the double stretch fabric?
①Dosage of warp yarn:
From the machine warp density, it can be seen that the number of warp yarns on the entire width of 81 inches/meter is: 76 (threads/inch) × 81 (inch) = 6156 (threads)
The thickness of 200D polyester is 22.2 tex, and the mass per unit length is: 22.2 (tex) ÷ 1000 (m) = 0.0222 (g/m)
Then the quality of 1m warp yarn is: 0.0222 (g/m) × 6156 (threads/m) = 137 (g)
②The amount of weft yarn:
The weft density is 46 threads/inch, and the number of wefts contained in 1m warp:
46 (pieces/inch) ÷ 2.54 (cm/inch) = 18 (pieces/cm)
18 (root/cm)×100 (cm/m) = 1800 (root/m)
The length of a single weft on the full width is: 81 (inch) × 2.54 (cm/inch) = 206 (cm/piece)
Then the quality of the entire width of the weft yarn is: 0.0222 (g/m) × 1800 (pieces/m) × 2.06 (m/piece) = 82 (g)
③Yarn consumption per extended meter:
The quality of yarn per extended meter in the whole width is: 137 (g) + 82 (g) = 219 (g)
If the quality of spandex is calculated at 4% of the grey fabric, its quality is estimated to be 9 grams. The quality of the trimmed fabric is 4% of the mass of the grey fabric, which is 9 grams, and the mass of the full-width extended meter grey fabric is: 219 (g/m) + 9 (g/m) + 9 (g/m) = 237 (g)
④Raw material price: 235 (g/m) × 16.46 (yuan/kg) = 3.87 (yuan/m)
⑤Weaving processing fee:
There are 1800 yarns per linear meter, that is, 1800 weft yarns are needed for every 1 meter weaving. Knowing that the processing fee for every 100 weft yarns is 0.11 yuan, the processing fee for 1800 weft yarns is: 1800 (threads/meter) × 0.11 (yuan/100 threads) = 1.98 (yuan/meter)
⑥Grey cloth cost: 3.87 (yuan/meter) + 1.98 (yuan/meter) = 5.85 (yuan/meter)
In the above calculation process, the spandex cost calculation is actually estimated according to known conditions, and the amount of spandex fiber yarn can also be accurately calculated according to the calculation methods of various fiber content in the grey cloth. The above calculation shows that the price of raw materials constitutes the main part of the price of grey cloth, and the fluctuation of raw material price has a greater impact on the price of grey cloth.
5. Factors affecting raw material prices
The prices of wool fiber and polyester fiber are far apart. The price difference between ordinary polyester low-stretch yarn DTY and polyester drawn yarn FDY of the same titer is also greater, while the price difference between polyester drawn yarn and sea-island yarn of the same titer is even greater. Compared with ordinary viscose fiber, the price of Modal fiber, which is a rich and strong fiber, and Tencel fiber, which is a wood pulp fiber, is several times more than that of ordinary viscose fiber. There is also a difference between ordinary cotton yarn and fine cotton yarn. Therefore, whether it is natural fiber, regenerated fiber or synthetic fiber, the basic properties of the fiber determine the fiber price.
The lower the fiber denier and the lower the production efficiency, the higher the price. The price difference between 55.5dtex polyester filament and 333.3dtex polyester filament is almost half. The price of 16s cotton yarn and 32s cotton yarn is also very different. In layman's terms, the finer the fiber, the higher the price.
5.3 Number of shares
Take polyester as an example. Compared with 165dtex/144f filament, 165dtex/72f filament has more single filaments, the more difficult it is to polymerize and draw, the better the flexibility, and the better the hand feel after processing. So the price of 165dtex/144f filament is higher. Take cotton yarn as an example, the price of 32s single yarn will be lower than 32s/2 strands.
5.4 Blending ratio
The blending ratio of polyester-cotton yarn and polyester-viscose yarn is relatively fixed, mostly polyester accounts for 65%, and cotton yarn or viscose yarn accounts for 35%. The blending ratio of wool-like fabrics has obvious variability. For example, the blending ratio of wool, polyester and acrylic "three-in-one" yarn can be 45/35/20, 49/36/15, or 51/24/25. In short, as the proportion of wool in blended yarns continues to increase, the price of raw materials will gradually increase.
5.5 Supply and demand
The fluctuation of textile prices has obvious seasonality. The price of raw materials and the cost of textiles fluctuate with the seasons, which are the main reasons for the fluctuation of textile prices. Fluctuations in textile prices caused by the supply and demand in the domestic market often have a greater impact on the healthy development of the textile industry, and attention must be paid when considering the overall cost of textiles.