Ultrasonic vibration-assisted injection molding method and device

Abstract

The invention discloses an ultrasonic vibration-assisted injection molding method and device and relates to the field of injection molding. The device comprises a forming mechanism, an injection mechanism and an ultrasonic vibration mechanism. The ultrasonic vibration mechanism is arranged between a plunger and a hydraulic device, an amplitude-change pole amplifies an ultrasonic vibration amplitude and transfers the same to the plunger, the plunger then transfers vibration to a melt, and injection molding in different conditions is met by changing the frequency, amplitude and vibrating mode ofultrasonic vibration. The method and device are wide in applicability, improve the quality of a plastic part, improve the flowing rate of a melted plastic in a charging barrel, a nozzle and a cavity,reduce the injection time, shorten the injection molding period and improve the percent of pass of the plastic part.

Description

technical field [0001] The invention relates to the field of injection molding, in particular to a method and device for ultrasonic vibration-assisted injection molding. Background technique [0002] Injection molding is a method in which heat-melted plastic is injected into a mold cavity by high pressure through an injection molding machine, and after cooling and solidification, a molded product is obtained. Injection molding has fast production speed, high efficiency, automatic operation, various designs and colors, shapes from simple to complex, and sizes from large to small, and the products are accurate in size, easy to update and replace, and can make plastic parts with complex shapes. Injection molding is suitable for molding processing fields such as mass production and products with complex shapes. [0003] Ultrasonic-assisted injection molding device and molding method for direct molding metal flash products (patent publication number CN104999633A) proposes that a...

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Problems solved by technology

However, the device and method did not improve the defects generated on the side of the injection machine, and did not solve the problems of the blockage of the molten material at the nozzle and the gate, and the large flow resistance of the molten material in the barrel.

[0004] In the process of injection molding, under-injection is prone to occur, and the design target shape cannot be achieved, that is, the injection is completed, and the cavity is not completely filled; the lack of forming is due to the defects formed by cooling and hardening of the molten injection molding resin before it is completely filled in the cavity. It may be that the injection pressure or injection speed is too low, and the exhaust effect is not good.

Depression (shrinkage pit) is the most common surface defect of molded products. It is caused by thermal shrinkage of molded products. The shrinkage volume can be solved by increasing the holding pressure, but when a high holding pressure is applied after the filling process is completed, residual stress will be formed inside the molded product and cause burrs to occur

In addition, during the injection molding process, the molten material often blocks the nozzle and the gate, and the gas in the molten material will also have a greater impact on the quality of the plastic part. Although the injection molding process is relatively mature at present, these problems still exist. exists, there is no better solution

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