The Zhejiang Wanxin Weishen Textile Technology Co., Ltd process of polyester includes two parts: polyester melt synthesis and melt spinning. The raw materials of synthetic polyester are polyethylene terephthalic acid and ethylene glycol, which are mainly obtained from petroleum cracking, but also from coal and natural gas. Petroleum is heated and cracked to obtain toluene, xylene and ethylene. After chemical processing, terephthalic acid or dimethyl terephthalate and ethylene glycol can be obtained. In the early polyester production, dimethyl terephthalate and ethylene glycol were used as raw materials because terephthalic acid was not easy to refine. In 1965, the refining of terephthalic acid was successful, which reduced the production process and cost of polyester. Polyester produced with terephthalic acid and ethylene glycol as raw materials has increased year by year. Polycondensation: Transesterification of dimethyl terephthalate and ethylene glycol, the resulting diethylene terephthalate oligomer, polycondensation at 280～290℃ and vacuum conditions to obtain polyterephthalic acid Ethylene glycol ester; or directly esterify terephthalic acid and ethylene glycol, and then polycondensate ethylene terephthalate to 100% wool yarn(48Nm/2) obtain a polyester melt.