Injection molds are parts that give plastics shape and scale during molding. Although the structure of the mold may vary due to the variety and function of plastics, the shape and structure of plastic products and the type of injection machine, the basic structure is common.
The injection molds are thermosetting plastic molds and thermoplastic plastic molds according to the molding characteristics; the mold transfer molds, blow molds, casting molds, thermoforming molds, hot compression molds (compression molds), injection molds, etc. During the hot press mold, it can be divided into overflow type, semi-overflow type, and non-overflow type. The injection mold can be divided into cold runner mold and hot runner mold by pouring system; Can be divided into two types: mobile and fixed. The classification of the mold is also different according to the processing technology. The injection mold is to inject the molten plastic into the cavity of the mold with a certain speed and pressure. After the plastic cools, open the mold and take out the molded injection product.
Compression molds are referred to as compression molds. Plastic materials are directly added to the open mold cavity, and the mold is closed. The plastic becomes active under the action of heating and pressure and fills the cavity, and then chemical crosslinking or physical cooling makes the product Hardening stereotypes.
Compression molds use heated molds to heat-constrain the plastic sheets, then open the molds, take out the molded products, and put them in cold water for cooling. Compression molding is an important skill process in molding processing. It is widely used in industrial production and industrial processing and plays an important role in people’s lives. Generally, powder, granular, agglomerate, flake, or even a blank similar to the product is first placed in the cavity of the heated mold, and then the mold is closed and pressurized to form and solidify or vulcanize, and then After demolding the product (see picture), this method is particularly suitable for the molding of thermosetting plastics (see thermosetting resins). The disadvantage is that the production cycle is long, the power is low, and the product scale accuracy is poor.