System of manufacturing injection molded article and metal mold

Abstract

In an injection process, molten resin is successively injected from a first flow channel and a second flow channel connected with each other in order into a cavity of a metal mold. High-temperature resin existing in the first flow channel is injected in advance into the cavity as a part of a single shot of molten resin to later form a skin layer of a molded article. other low temperature resin near a flowable limit existing in the second flow channel is subsequently injected into the cavity as another part of the single shot of molten resin to later form a core layer of the molded article. A low temperature resin remaining in the first flow channel when injection is completed is warmed to be a high-temperature resin before the next cycle, thereby allowing successive molding of molded articles.

Description

CROSS-REFERENCE TO RELATED APPLICATION[0001]This patent application is based on and claims priority to Japanese Patent Application 2018-169487, filed on Sep. 11, 2018 in the Japan Patent Office, the entire disclosure of which is hereby incorporated by reference herein.BACKGROUNDTechnical Field[0002]Embodiments of this disclosure relate to a system of manufacturing an injection molded article and a metal mold.Related Art[0003]In a known manufacturing system of manufacturing an injection-molded article, multiple shots of molten resin are supplied from multiple sources and are sequentially injected into a cavity.[0004]In recent years, in a process of manufacturing injection molded articles, it is demanded that a molding cycle is further shortened. In this point of view, a known equipment disclosed in the first patent literature has room for improvement, because it cannot sufficiently shorten the molding cycle.[0005]Various embodiments of the present disclosure have been made in view of...

AI Technical Summary

Benefits of technology

The patent describes a manufacturing system and a metal mold that achieve a faster molding cycle and reduced defects in the appearance of the injection molded article. This is achieved by setting the temperature of the molten resin injected into the cavity to a low level near its flowable limit, which reduces the time required for solidification. Additionally, the temperature of the molten resin that forms the skin layer of the article is set to a higher level, which lowers its melt viscosity and helps prevent defects in appearance.

Problems solved by technology

In this point of view, a known equipment disclosed in the first patent literature has room for improvement, because it cannot sufficiently shorten the molding cycle.

Images