Classified by molding(1) Injection molding is to first add plastic to the heating barrel of the injection machine. The plastic is heated and melted. Under the push of the injection machine screw or plunger, the nozzle and the mold casting system enter the mold cavity due to physical and chemical effects. The hardening is shaped into an injection molded product.  (2) Compression molding, commonly known as press molding, is one of the methods for molding plastic parts earlier. Compression molding is to directly add plastic to an open mold cavity with a certain temperature, and then close the mold, and the plastic melts into a flowing state under the action of heat and pressure. Due to physical and chemical effects, the plastic is hardened into a plastic part having a constant shape and constant shape and size.  (3) Extrusion molding is a process in which a plastic in a viscous state is passed through a die having a specific cross-sectional shape at a high temperature and a certain pressure, and then formed into a continuous profile of a desired cross-sectional shape at a lower temperature. A molding method.  (4) Injection molding is also called casting molding. The plastic raw material is added into the preheating feeding chamber, and then the pressing column is placed in the feeding chamber to lock the mold, and the pressure is applied to the plastic through the pressing column, and the plastic is melted into a flowing state under high temperature and high pressure, and enters the cavity through the pouring system. Gradually solidified into plastic parts. (5) Hollow molding is to fix the tubular or sheet-like blank material which is still in plasticized state by extrusion or injection into the molding die, and immediately introduces compressed air to force the material to expand and stick to the mold type. On the wall surface of the cavity, after being cooled and shaped, the mold is released, that is, a processing method of the desired hollow product is obtained. (6) Die-casting mold The die-casting mold is also called transfer molding mold. The plastic raw material is added to the preheating feeding chamber, and then the pressure is applied to the pressing column. The plastic is melted under high temperature and high pressure, and enters the cavity through the casting system of the mold, and is gradually hardened. This molding method is called die casting molding.    Plastic molds can be divided into three categories depending on the casting system:(1) Dashuikou mold: The runner and gate are on the parting line, and the product is demolded together when the mold is opened. The design is simple, easy to process, and the cost is low. Therefore, many people use the large nozzle system. (2) Sluice nozzle: The runner and gate are not on the parting line, generally directly on the product, so it is necessary to design a set of nozzle parting lines. The design is more complicated and difficult to process. Generally, it depends on the product requirements. Fine water system. (3) Hot runner mold: This type of mold structure is basically the same as the fine water nozzle. The difference is that the flow channel is in one or more constant temperature hot runner plates and hot nozzles, no cold material release, flow channel and gate. Directly on the product, so the flow channel does not need to be demoulded. This system is also called the waterless port system, which can save raw materials, is suitable for the case where the raw materials are expensive and the product requirements are high, the design and processing are difficult, and the mold cost is high.