JPS5686714A - Curing method of molded article - Google Patents

Abstract

PURPOSE: To reduce a thermosetting time of a thermoplastic resin molded article by a method wherein an initial heating is performed for the thermoplastic resin molded article under a lower temperature than a transision point of glass and the final heating is performed under an approximately equal temperature to the transition point of glass.

CONSTITUTION: When an article molded from a thermoplastic resin compound is heated to be cured, the molded article is heated under a temperature lower than the glass transition point after the setting of the molded article, and then, the temperature is gradually raised and at a stage of a setting completion, it is heated under a temperature approximately equal to the glass transition point after a setting. A glass transition point of the molded article wherein a curing is not finished, rises, in general, as the curing advances, and at a stage when a curing is completed, it reaches a constant high glass transition point. And further, the speed of a curing reaction generally increases as a temperature increases, however, when a curing temperature exceeds sharply a glass transition point at that stage, a stress relaxation speed becomes small and an apparent curing speed becomes small, reversely. Owing to the aforementioned reason, a heating as aforementioned is performed.

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