Plastic compression molding molds include two types of structural molds, compression molding and injection molding. They are a type of mold that is mainly used to form thermoset plastics, and the corresponding equipment is a pressure forming machine.
The compression molding method heats the mold to the molding temperature (generally 103°-108°) according to the characteristics of the plastic, and then puts the metered pressed plastic powder into the mold cavity and the feeding chamber, and closes the mold, and the plastic is under the action of high heat and high pressure. It is softened and viscous, solidified and shaped after a certain period of time, and becomes the shape of the desired product.
Different from injection molding and compression molding, there is a separate feeding chamber. Before molding, the mold is closed first, and the plastic is preheated in the feeding chamber to be in a viscous flow state. Under the action of pressure, it is squeezed into the mold cavity and hardened.
Compression molds are also used to mold certain special thermoplastics such as difficult-to-melt thermoplastics (such as polyfluoroethylene) blanks (cold press molding), optical lenses with high optical properties, lightly foamed nitrocellulose car steering wheels, etc.
The compression molding die is mainly composed of a cavity, a feeding cavity, a guiding mechanism, a pushing part, a heating system and the like. Injection molds are widely used to package electrical components. The material used in the manufacture of compression molding is basically the same as that of the injection mold.