Low-pressure glue injection method and glue injection machine using LD-PE material

Abstract

The invention relates to the technical field of LD-PE material injection molding, in particular to a low-pressure glue injection method and glue injection machine using an LD-PE material. The method comprises the following steps that (1) an LD-PE glue solution is conveyed to a glue injection gun through a gear pump; (2) opening and closing of the glue injection gun are controlled through a fluid valve; and (3) a gun head of the glue injection gun stretches into the edges of water gaps of a forming mold or into the water gaps to carry out glue injection. The forming mold is provided with inserted connection holes allowing the gun head of the glue injection gun to be inserted, the bottoms of the inserted connection holes communicate with the water gaps, every two mold cavities of the forming mold correspond to one water gap, one water gap corresponds to one inserted connection hole, each water gap is located between the two corresponding adjacent mold cavities, and the two ends of each water gap communicate with the opposite faces of the two corresponding mold cavities correspondingly. By means of the low-pressure glue injection method and the glue injection machine, low-pressure glue injection of the LD-PE material is achieved, raw material waste caused by excessive water gap materials is greatly reduced, and the rejection rate of injection molded products, especially wire harness products such as connectors and USB connectors, is reduced.

Description

technical field [0001] This application relates to the technical field of LD-PE material injection molding, in particular to a low-pressure glue injection method using LD-PE material and a glue injection machine. Background technique [0002] In the connection between the wire harness of the current electronic product and the PCB board, it is necessary to perform injection molding and solidification on the connection through an injection molding process to form a packaging inner mold, so as to achieve the purpose of protecting the solder joints and connecting lines. It is especially suitable for the internal mold encapsulation processing of the connection between the PCB board and the wiring harness of the USB connection male or female. The raw materials of the existing injection molding process mainly include LE-PE material and hot melt adhesive. LE-PE material is cheap (12.3 yuan / kg), has high hardness, and has good protection performance for products. It is widely used. ...

AI Technical Summary

Problems solved by technology

Although LE-PE material is high in quality and low in price, due to its high viscosity and hardness, the injection pressure required in the existing injection molding process is also extremely high. The tree-shaped nozzle design of the nozzle and the long nozzle length greatly increase the pressure required for injection molding of LE-PE materials. Under the action of high pressure, the liquid rubber material forms a high-speed and high-pressure rubber fluid to the fine lines and solder joints of the wiring harness. Great impact force is formed, therefore, the product rejection rate due to the rubber fluid punching through thin lines or punching out solder joints has also remained high

Some manufacturers use hot melt adhesive to reduce the pressure of the injection molding process, thereby reducing the reject rate of the product, but the price of hot melt adhesive is high (130 yuan / kg), and the hot melt adhesive is soft after curing, and its own hardness Low, the protection of the wiring harness and solder joints at the connection is low, the connection is easily damaged during the use of the product and an open circuit problem occurs, the overall service life of the product is short, and the existing low-pressure plastic machine using hot melt adhesive cannot To achieve low pressure in the true sense, it can only be achieved when hot melt adhesive is used, and LE-PE material cannot be used for low pressure injection molding

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