The structure of the injection mold is determined by the type of injection molding machine and the structural characteristics of the plastic part. Each mold is composed of a movable mold and a fixed mold. The movable mold is installed on the movable plate of the injection molding machine, while the fixed mold is installed on the fixed plate of the injection molding machine. During injection, the movable mold and the fixed mold form a pouring system and cavity after being closed. The part is left on the side of the movable mold, and then the plastic part is ejected by the demoulding mechanism set in the movable mold. According to the different roles of various parts in the mold, a set of injection mold can be divided into the following parts:
1. Molded parts
The parts that give the shape, structure, and size of the molding material, usually composed of cores (punch molds), concave mold cavities, threaded cores, inserts, etc.
2. Pouring system
It is the channel that leads the molten plastic from the nozzle of the injection machine to the closed mold cavity, and is usually composed of a main runner, a runner, a gate and a cold well.
3. Guiding parts
In order to ensure that the movable mold and the fixed mold can be accurately aligned when they are closed, the guide part is used for guiding and positioning. It is composed of a guide post and a guide sleeve. Some injection molding molds are also equipped with guide parts on the ejector plate, ensuring the smooth and reliable movement of the demoulding mechanism.
4. Demoulding mechanism
The device that realizes the demolding of plastic parts and the pouring system has many structural forms. The most commonly used are ejector pins, ejector pipes, top plates and pneumatic ejector ejection mechanisms, which are generally composed of ejector rods, reset rods, slingshots, ejector fixed plates, It is composed of top plate (top ring) and top plate guide post/guide sleeve.
5. Mold temperature adjustment system
In order to meet the mold temperature requirements of the injection molding process, a mold temperature adjustment system is required to adjust the mold temperature.
6. Exhaust system
In order to smoothly exhaust the gas in the mold cavity, an exhaust groove is often set at the parting surface of the injection mold and the fitting position of the insert.
7. Other structural parts
Refers to the parts (such as: fixed plate, movable/fixed template, support column, support plate and connecting screw) set to meet the requirements of mold structure.