SYNTHETIC RESIN MOLDING METHOD

摘要

A synthetic resin molding method in which the molding is done by using a metal mold which is obtained by covering a cavity-forming wall surface of a metal mold body with one or not less than two insulating layers of a heat resisting polymer, and which has a difference between a thermal expansion coefficient of the metal mold body-contacting insulating layer and that of the metal mold body of less than 2 x 10<-5>/ DEG C. When the method according to the present invention is used for the injection molding or blow molding of a synthetic resin using a metal mold coated with a special insulating layer, the separation of the insulating layer from the metal mold does not occur, and the metal mold comes to have a durability. This method also enables a molded product having a good external appearance to be obtained. The method according to the present invention therefore enables an injection molded product, such as a housing for a light electric appliance, which has heretofore required a posterior process, such as painting due to many weld lines occurring thereon, to be obtained without carrying out a painting step.