A plied yarn is a thread formed by bonding two or more single yarns. The strands can also be plied, combined and bonded in a certain way, and the strands can be re-bonded, such as double-strand, triple-strand and multi-strand. Mainly used for sewing thread, braided thread or medium-thick and strong fabrics. 
　　Conventional strands are usually made of pure cotton or blended two single yarns or more than two single yarns bonded together. In recent years, fancy strands are made of two or more different single yarns bonded together, such as : Pure cotton and blends, plain and slub yarns, and plain and filament yarns, etc.
　　Pure cotton yarn is made of cotton fiber. According to different spinning processes, it can be divided into carded yarn and combed yarn. Carded yarn is a yarn spun from cotton fibers through a common spinning system. The combed yarn is a yarn spun from cotton fibers through a combed spinning system. The combed yarn is made of raw materials. The fibers in the finished yarn are straight and parallel, with less knots, good luster, and evenness. This kind of cotton yarn is mostly used for weaving fabrics. Cotton yarn is widely used, it can be used as weaving yarn, such as: bed sheets, quilt covers, curtains and other home textile series. It can also be used as knitting yarn, especially combed yarn can be used to produce high-quality textiles, such as undershirts, fine-grained poplin, etc. Cotton yarn can also be used to produce electrical yellow wax cloth, tire cord fabric, high-speed sewing thread and Embroidery thread, etc. Pure cotton fabrics are made of cotton as raw materials and produced by textile technology. They have the characteristics of moisture absorption, heat resistance, alkali resistance and hygiene. Generally speaking, pure cotton fabrics have better moisture absorption and heat resistance, and wear. Some work clothes in industries that require high hygroscopicity of clothing can choose pure cotton fabrics for processing. For example, summer school uniforms, etc.
　　According to the national standard, the yarn quality is rated according to the quality index and weight unevenness. Cotton yarns are rated according to evenness, neps, and number of foreign particles. The quality index mainly refers to the strength of the yarn, which reflects the durability and durability of the fabric to a certain extent. The grade of the yarn mainly reflects the difference in the thickness of the yarn and the appearance defects, which directly affects the appearance of the fabric, such as the evenness of the texture, the size of the clarity and the shadow, etc. The quality of yarn is closely related to production management, process conditions, mechanical conditions, technical operation level, the quality of raw cotton and its rational use. Pure cotton fabric is a textile made of cotton as raw material, and through the loom, the warp and weft yarns are interwoven vertically and horizontally. At present, according to the actual source of processed cotton, it is divided into virgin cotton fabric and cotton fabric. Cotton with a cotton content of more than60is pure cotton. Don't39;t think that pure cotton is cotton. They still have different places.