MANUFACTURE OF MOLDED PRODUCT OF FLAME RETARDING THERMOPLASTIC RESIN

PURPOSE:To obtain high quality product described in the titled, when a thermoplastic resin including halogen series flame retarding agent is extruded and molded, by supplying inactive gas to an extruder when it is extruded, thereby suppressing the decomposition of the halogen series flame retarding agent. CONSTITUTION:When the thermoplastic resin 2 (e.g. polypropylene, polyvinyl chloride) including the halogen series flame retarding agent whose decomposition temperature lies within the range of 150-300 deg.C, such as halogenized ester phosphate, aromatic halogen compound, and aliphatic halogen compound, is extruded and molded, the normal state inactive gas (e.g. nitrogen gas, carbon dioxide gas) whose capacity is larger than that of the supplied resin is supplied to the extruder from an inactive gas supplying pipe before the resin is melted. Then by performing the extrusion with the supply of the inactive gas being continued, the decompositon of the halogen series flame retarding agent is suppressed, and the molded products without degradation of the strength, and discoloration, and the like is obtained.