Multi-variety production includes yarns with different counts, yarns with different technological processes and processing methods, and yarns with different uses. The purpose of cotton distribution is to use raw cotton more rationally, because yarn quality and characteristics are not required. The same, and the spinning process has its own characteristics. Therefore, various yarns have different quality requirements for the use of raw cotton.
01 different count yarns
High-count yarn generally refers to yarn with a count of 50 or more. It is generally used in high-end products. It requires high yarn strength, few appearance defects, and uniform evenness. The diameter of high-count yarn is smaller and the number of fibers contained in the cross-section is larger. If it is less, defects are easily exposed, and the fiber number distribution in the cross-section is uneven, which has a greater impact on the evenness level of cotton yarn. On the contrary, the requirements for low-count yarn are relatively lower. Therefore, different grades should be selected according to different counts when matching cotton. Raw cotton of different qualities.
02 Combed yarn and carded yarn
Combed yarn is generally a high-end product that requires good appearance, uniform evenness, and few neps and impurities. The combing process can remove a large number of short fibers and some impurity defects, but it is more difficult to remove neps. Therefore, the cotton used for combing requires the raw cotton linters and neps to be as low as possible. If the maturity is too poor, the tax rate will be too high. If neps are produced, use as little as possible. Because combed products are used to make high-end fabrics, they have higher requirements for the dyeing effect of the cloth. Therefore, raw cotton with good color and good uniformity is selected, and sometimes long-staple cotton is required.
03 Single yarns and strands
Generally, single yarns are twisted in the backhand direction, and strands are twisted in the forward direction. The angle between the fibers in the strands and the strand axis is small, so the fiber utilization rate is high, the strength is greatly enhanced, and evenness is improved. Generally, evenness is improved. The level can be improved by 2%-3%. Since most of the hairiness and defects are wrapped inside the yarn, the chance of being exposed to the outside of the yarn is reduced, so the number of hairiness and defects is also greatly improved. Strands are generally used with warp yarns, so the cotton grade and quality may be reduced.
04 Warp and weft
The warp yarns undergo more tension and friction opportunities during use, so the warp yarn strength requirements are higher. When blending cotton, raw cotton with slender fibers, high single fiber strength, moderate maturity, and good uniformity should be selected. In the weaving process, there are many opportunities to remove neps and impurities on the yarn, and it also needs to go through the sizing process, so the requirements for the color and impurity content of the raw cotton are low, the weft yarn is not sizing, the preparation process is simple, there are few opportunities to remove impurities, and the weft yarn It is mostly exposed on the surface of the fabric, so the weft yarn has a greater impact on the color, appearance, feel and other factors of the fabric. However, the weft yarn does not have high requirements for strength, so you can choose raw cotton with good color, less impurities, thicker and shorter, and slightly lower tension.
05 Yarn for knitting
Knitwear is made of single or several yarns knitted by knitting machines. It has high requirements on yarn breakage, defects, strength and dyeing effect. Knitted yarn is generally used to make underwear and is required to be soft and comfortable, so the yarn The twist is small, and knitting yarns have high requirements for evenness evenness. Yarns with uneven thickness are particularly obvious on fabrics. Therefore, when blending cotton, the yarn strength, evenness, defects, and number of broken ends must be carefully considered in all aspects. Take care of it, so you should choose raw cotton with slender fibers, good uniformity, normal maturity, low short staple rate, and few defects. For knitting yarn for fleece fabrics, you should choose raw cotton with good maturity, good elasticity, and short length. .
06 Yarn for dyeing
Generally, cotton fabrics need to be finished and dyed. The color absorption capacity of the fabric is closely related to the performance of the fiber. Light-colored fabrics do not have high requirements for raw cotton, but raw cotton with low maturity coefficient and large difference cannot be used, otherwise It will cause uneven fiber mixing, and spots or stripes will appear on the fabric after dyeing. Therefore, light-colored fabrics require the use of raw cotton with less impurities and better color. Dark fabrics have high requirements for fiber color absorption capacity and good maturity of raw cotton. Printed fabrics can have lower requirements for raw cotton, because after printing, some yarn defects and rungs on the cotton fabric can be covered. For yarn-dyed yarns, the requirements are The highest yarn used for one-color cloth fabrics, one-color cloth is also called Mitong cloth, which uses dyed yarn to weave high-end decorative or clothing fabrics. Because the yarn has to go through multiple processes during the dyeing process, the yarn is required to be free of hairiness, yarn defects, and joints. Currently, there are very few yarns in China that can reach high-end single-color fabrics.
07 Special yarn
There are many types of yarns for special use, such as tire cords, high-end sewing threads, decorative fabric yarns, handkerchief yarns, etc. It is required to select specific cotton based on quality requirements when blending, and must not create a universal cotton blending phenomenon.
In the yarn purchase contract, in addition to requiring the yarn mill to order yarn according to the purpose of the yarn, many orders also require specific quality and technical indicators of the yarn, such as evenness CV value, nep defects in the finished yarn, etc., as well as the quality of the cotton yarn. In addition to being related to production management, process conditions, mechanical status, operating level, etc., it has a lot to do with the quality of the raw cotton used and the reasonable use of it. Therefore, we must master the different requirements of yarn quality on raw cotton, and the differences between them. Interrelationship, giving full play to the technical performance of raw materials, when the cost of cotton distribution is relatively low, it plays an important role in improving yarn quality, stabilizing production, and reducing production costs.
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