Sewing thread is the thread needed for knitted clothing products. The sewing thread can be divided into three categories: natural fiber sewing thread, synthetic fiber sewing thread and mixed sewing thread. With the development of polyester industry, sewing thread with pure polyester fiber as its raw materials more and more. Polyester fiber is a good quality synthetic fiber, used to obtain the suture strength is high, in all sorts of nylon thread, second only, and wet state will not reduce the intensity. Its shrinkage is very small, after the appropriate shape after the contraction of less than 1%, so the sewing stitching can always maintain a very beautiful, without shrinkage. Wear resistance after nylon. Low moisture regain, a good high temperature, low temperature, light and water resistance. Therefore, the polyester line is the use of very wide variety, in many occasions, replacing the cotton sewing thread. Polyester thread widely used, can be used for cotton fabric, chemical fiber fabric and blended fabric sewing, sewing knit coat can also be used. A special line of polyester or leather shoes and leather industry with fine lines.