The types of automotive molds include injection molding, stamping, forging, casting and other types. Each type of mold corresponds to different types of parts production. Now more and more parts are produced in plastic, and injection molds play a very important role. The classification of automotive injection molds can be roughly divided into the following categories.
There are many ways to classify automotive injection molds, which can be divided into the following categories according to the different methods of molding and processing plastic parts:
Injection mold is also called injection mold. The molding process of this mold is characterized by placing the plastic raw material in the heated barrel of the injection machine. The plastic is heated and melted, and driven by the screw or plunger of the injection machine, it enters the mold cavity through the nozzle and the gating system of the mold, and the plastic is formed in the mold cavity through heat preservation, pressure maintenance, cooling and solidification.
Since the heating and pressing device can function in stages, injection molding can not only form plastic parts with complex shapes, but also has high production efficiency and good quality. Therefore, injection molding occupies a large proportion in the molding of plastic parts, and injection molds account for more than half of plastic molding molds. Injection machines are mainly used for the molding of thermoplastics, and have gradually been used for the molding of thermosetting plastics in recent years.
Compression mold is also called compression mold or rubber mold. The molding process of this kind of mold is characterized by adding plastic raw materials directly into the open mold cavity, and then closing the mold. After the plastic is in a molten state under the action of heat and pressure, the cavity is filled with a certain pressure.
At this time, the molecular structure of the plastic undergoes a chemical cross-linking reaction, gradually hardening and shaping. Compression molds are mostly used for thermosetting plastics, and their molded plastic parts are mostly used for electrical switch casings and daily necessities.
Transfer mold is also called injection mold or extrusion mold. The molding process of this kind of automotive injection mold is characterized by adding plastic raw materials into the preheated feeding chamber, and then applying pressure to the plastic raw materials in the feeding chamber by the pressure column. The plastic melts under high temperature and high pressure and enters the cavity through the pouring system of the mold. , and then a chemical cross-linking reaction occurs to gradually solidify and shape. The transfer molding process is mostly used for thermosetting plastics, which can form plastic parts with more complex shapes.
The extrusion die is also called the extrusion head. This mold can continuously produce plastics with the same cross-sectional shape, such as plastic pipes, rods, sheets, etc. The heating and pressurizing device of the extruder is the same as that of the injection machine. The plastic in the molten state passes through the machine head to form continuous molded plastic parts, and the production efficiency is particularly high.
In addition to the several types of automotive injection molds listed above, there are also vacuum forming molds, compressed air molds, blow molding molds, and low-foaming plastic molds.