PROCESS FOR PREPARING POLYETHYLENENAPHTHALATE FIBER

摘要

A manufacturing method of a polyethylene naphthalate fiber is provided to increase maximally the viscosity of prepolymer and to use a relax nozzle when discharging the prepolymer. The naphthalene dicarboxylate and the esterification reaction materials of diol are melted and polymerized so that the polyethylene naphthalate pre-polymer with the inherent viscosity of 0.45 to 0.75 dl/g is obtained. The obtained pre-polymer is passed through a modified nozzle, rapidly cooled and then cut by a cylindrical model with a hollow shape. A chip with high viscosity is manufactured through the cut pre-polymer chip through the solid polymerization process. The chip with high viscosity is manufactured by the melting and spinning processes. The melting point of the solid polymer is below 270 degrees centigrade and the density thereof is below 1.355. The distribution of molecular weight is below 1.75.