Decompression micro-foaming injection molding device and process thereof

Abstract

The invention provides a decompression micro-foaming injection molding device and a process thereof, belongs to the field of injection molding, and solves the problems that existing supercritical fluid and polymers are poor in mixing, and a screw rod is uneven in stress. The decompression micro-foaming injection molding device comprises a high-pressure gradient mixing screw rod head, an injection molding screw rod, gas homogenizers, a machine head, a machine barrel, a supercritical fluid pressure control module and a screw rod displacement monitoring module, the plurality of gas homogenizers connected with an external gas supply unit are arranged on the machine barrel, and the high-pressure gradient mixing screw rod head is connected with the injection molding screw rod through nesting or threads. When a screw rod head is close to one of the gas homogenizers, an inlet valve at the part is opened, inlet valves at other parts are closed, and the pressure gradient generated by rotation of the screw rod head turns out core layer materials, so that supercritical fluid and the materials are fully dissolved, the supercritical fluid pressure control module controls the gas injection pressure and temperature, and the screw rod displacement monitoring module assists in positioning the position of the high-pressure gradient mixing screw rod head.

Description

technical field [0001] The invention belongs to the technical field of injection molding, and relates to a decompression micro-foaming injection molding device and a process thereof. Background technique [0002] The traditional injection molding micro-foaming process is to open a hole in a fixed position of the barrel, and with the plasticizing retreat of the screw, the supercritical fluid and the polymer melt are forcibly dissolved and mixed in a high temperature and high pressure environment, and stored in the metering section. Advance through the screw to inject the material into the mold. Due to the release of pressure in the mold, the cells in the polymer melt grow and refine, and the product is processed after cooling and shaping. [0003] For example, the invention patent application number: 201510230502.8 discloses a circulating remixing micro-foaming screw, which supplies air to the material by opening vent holes inside the screw, and dissolves the material and th...

AI Technical Summary

Problems solved by technology

The processing of the screw is difficult; there are also problems of uneven gas distribution and uneven force on the screw; the screw is hollow, and the strength of the screw will be reduced, and it is not suitable for the processing of small-diameter screws and high-viscosity materials; materials and supercritical Insufficient fluid contact, low dissolution efficiency, and product quality cannot be guaranteed

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