The flat wire process is the first and most important process in the production of Muguang Plastics. Flat yarn is a chemical fiber monofilament with a flat cross-section, which is the basic material for the production of woven cloth. The flat yarns are made of specific types of polypropylene and polyethylene resins through melt extrusion to form films, which are slit longitudinally into strips, and the strips are heated at the same time for drawing orientation and then shaped, and finally wound into flat yarn spindles. To ensure the strength of the base fabric for the ton bag, the tensile strength of the flat yarn must be improved. What we have to do is not only to strictly control the quality of raw materials, but also to pass multiple inspections in each production process.