Die injection molding is a machining method used for mass production of some parts with messy shapes. The specific principle is: the plastic raw materials that are heated and melted are pushed into the cavity of the plastic mold with the screw of the injection molding machine under high pressure, and the plastic molding products are obtained after cooling and curing.
　　The plastic mold consists of a movable mold and a fixed mold. The movable die is installed on the movable template of the injection molding machine, and the fixed die is installed on the fixed template of the injection molding machine. During injection molding, the movable die and the fixed die are closed to form the pouring system and cavity. When opening the mold, separate the active mold from the fixed mold to remove the plastic product.
　　Although the structure of the plastic mold may vary greatly depending on the type and function of the plastic, the shape and structure of the plastic product, and the type of injection molding machine, the underlying structure is the same. The structure of the plastic mold is divided by function, which is mainly composed of: pouring system, temperature control system, molding parts system, exhaust system, guiding system, ejecting system and so on. Among them, the casting system and molded parts are the parts that are in direct contact with the plastic and change. With plastics and products. They are the most messy part of plastic molds, vary greatly, and require high processing finish and precision. Gate system: refers to the part of the runner before the plastic enters the cavity from the nozzle, including the main runner, cold block, runner and gate.