Cotton yarn is made of cotton fiber through spinning process, which is called cotton thread after joint stock processing. According to the different spinning process, it can be divided into the universal carded yarn and the combed yarn. (1) Carded yarn: yarn made of cotton fiber through a common spinning system. (2) Combed yarn: yarn made of cotton fiber through the combed spinning system. Combed yarn is made of high quality raw materials, and this yarn is straight, glossy, evenness and it has less mixed and high strength. This kind of cotton yarn is usually used for weaving high-grade fabrics.