1. Injection device of injection molding mold
The injection molding mold has two parts: a clamping device and an injection device. The clamping device can close the injection mold under injection pressure. It should be noted that before the plastic is injected into the mold, it must be melted, and then the pressure and speed must be controlled to inject the melt into the mold.
Under normal circumstances, injection molding molds have two types of injection devices: a screw preplasticizer and a reciprocating screw. The screw type preplasticizer has the characteristics of constant melt quality, high pressure and high speed, and precise injection volume control. The device uses a preplasticizing screw (first stage) to send molten plastic into the injection rod (second stage), and is often used The production of transparent, thin-walled products is required for high productivity. Screw preplasticizers also have disadvantages, such as uneven residence time, higher equipment costs and maintenance costs. The reciprocating screw injection device is widely used and can complete the melting and injection steps of plastic without a plunger.

Second, the demolding method of injection molding mold
1. Forced demoulding
Forced demolding is suitable for injection molds with simple structure and is characterized by high efficiency. It is often used in low-precision applications. For soft plastic products such as polyethylene and polypropylene, semi-circular coarse-tooth threads with a small depth should be adopted, and the products should be extruded out of the core by the push plate of the injection mold. It is worth mentioning that, due to the large demolding force, the pushing surface area should be designed to be larger.
2. Manual demoulding
Manual demolding is suitable for injection molds with simple structure. It has the characteristics of high precision, low efficiency and high labor intensity. It is often used for small batch production. After the injection mold is opened, the core or ring will be ejected from the injection mold together with the product, and then the thread will be manually removed with a tool outside the injection molding machine to complete the demolding step. Although the manual operation efficiency in the mold is high, the operation is difficult, and the threaded core or the ring needs to be used alternately, and the product will remain in the mold after the mold is opened, and the threaded core needs to be removed with a wrench.
3. Motorized demoulding
Motorized demolding is suitable for injection molds with complex structures. It has the characteristics of high efficiency and high precision, and is widely used. Among them, the Huff die is used for external threads, the flap core die is used for internal threads, and the rack and pinion mechanism is commonly used to unthread the threads.