Spandex is the abbreviation of polyurethane fiber, which is a kind of elastic fiber. Spandex is generally composed of multiple filaments, usually 10D/root. Currently, there are 15D/root, or even 20D/root. The less the number of theoretical roots, the better the evenness of the evenness, because the chance of overlapping forms is less. DMAC, the production solution of spinning, is harmful to the liver of the human body. Generally, 10D/root contains 0.5mg/kg, such as 15D/root contains 0.7mg/kg, which exceeds the standard. When producing Spandex, special attention must be paid to the winding tension, the number of counts on the tube, the breaking strength, the breaking elongation, the degree of forming, the amount of oil adhesion, the elastic recovery rate, etc., which directly affect the knitting, especially the knitting production Pay more attention to single-sided fabrics.