A molding device for avoiding weld lines in high polished metal injection molding

Abstract

The invention relates to the technical field of injection molding to avoid weld lines, and discloses a molding device for avoiding weld lines in high-polish metal injection molding, including a casing, the inner top wall of the casing is fixedly connected with a guide rail, and the surface of the guide rail is fixedly connected There is an injection groove, the surface of the guide rail and the two sides of the injection groove are slidingly connected with push rods, the end of the push rod away from the guide rail is hinged with the injection groove, and the end of the injection groove away from the guide rail is fixedly connected with a baffle, and the baffle is far away from the side of the injection groove One side is fixedly connected with a flow mechanism. Due to the increase in the amount of molten material, the blocking block is pushed away under the clamping of the return spring, and the molten material enters the cavity. When the restricting block moves to the surface of the inflow port, it will be blocked by the inflow port and will not move again. At the same time, the air blocking block is pushed away by the compression spring, the airflow pipe is opened, and the heated airflow flows into the shell and blows on the surface of the molten material, so as to keep the temperature of the molten material from decreasing with the flow distance Effect.

Description

technical field [0001] The invention relates to the technical field of avoiding welding lines in injection molding, in particular to a molding device for avoiding welding lines in highly polished metal injection molding. Background technique [0002] The thin lines produced at the fusion of molten materials during injection molding are called weld lines. Weld lines only occur at the joints of molten materials. The generation of weld lines has an impact on the strength and appearance of molded objects, because it is a highly polished metal injection molding material. [0003] Among them, the weld mark is caused by the diversion and convergence of several streams of material in the mold during injection or extrusion. The melt is not completely fused at the interface, and cannot be welded together with each other, resulting in fusion marks. For metal products with high polishing requirements, welding The existence of traces will inevitably lead to its failure, which will affect...

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Problems solved by technology

[0003] Among them, the weld mark is caused by the diversion and convergence of several streams of material in the mold during injection or extrusion. The melt is not completely fused at the interface, and cannot be welded together with each other, resulting in fusion marks. For metal products with high polishing requirements, welding The existence of traces will inevitably lead to its unqualified, and then the appearance quality and mechanical properties of plastic parts

[0004] In response to this problem, corresponding injection molding equipment was invented to reduce the probability of weld lines by controlling the temperature of the cavity, injection pressure and flow velocity of the melt. However, the existing equipment cannot completely eliminate weld lines. The injection molding equipment is made of metal, and the molded objects are made of plastic. The heat dissipation speed of the two is definitely different. However, the injection molding is in a closed environment, and the external temperature cannot be transmitted to the inside in time, so that the temperature difference between the two cannot be compensated in time; In addition, because the flow rate of the melt is related to the injection pressure and its own temperature, when the melt enters the cavity, as its own temperature decreases, the flow speed slows down, and eventually it will not be able to weld with other temperatures. The phenomenon of integration, so a high-polish metal injection molding device that avoids weld marks came into being

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