Classification of imported plastic molds in molding of plastic products

Mold is an important process equipment of modern industry and an indispensable part of the production of many industrial products. The types of molds are usually classified according to different processing objects and processes. From the perspective of industry, there are mainly plastic molds , rubber molds, metal cold stamping molds, metal cold extrusion molds and hot extrusion molds, and metal drawing molds. , powder metallurgy molds, metal die-casting molds, metal precision casting molds, glass molds, glass steel molds, and so on. In the following, only the different types of molds used in the molding of the most common plastic products are classified and introduced.

The most common molding methods for plastics are generally divided into two categories: melt forming and solid phase forming: melt forming is a method in which plastic is heated above the melting point to make it in a molten state for molding, and molding is a molding method of this type. The main processes include injection molding, compression molding (shrinking) molding, extrusion molding, etc. Solid phase molding refers to a type of molding method in which plastics are kept in a solid state below the melting temperature, such as vacuum molding and compressed air molding in the production of some plastic packaging containers. And blow molding, etc. In addition, there are liquid molding methods such as casting, slush molding and dip molding.

According to the above different molding methods, the types of plastic processing molds corresponding to different process requirements can be divided, mainly including injection molding molds, extrusion molding molds, compression molding molds, blow molding molds, plastic forming molds, and high-expansion polystyrene. Ethylene molding die, etc.

Plastic injection (plastic) mold

It is mainly a molding mold which is most commonly used in the production of thermoplastic parts. The processing equipment corresponding to the plastic injection molding mold is a plastic injection molding machine. The plastic is first heated and melted in the heating barrel of the injection machine, and then in the injection machine. Pushed by the screw or the plunger, the injection system of the nozzle of the injection machine and the mold enters the mold cavity, and the plastic is cooled and hardened to form a product. The structure is usually composed of a molded part, a pouring system, a guiding part, a pushing mechanism, a temperature regulating system, an exhaust system, a supporting part and the like. The manufacturing materials usually use plastic mold steel modules. The commonly used materials are mainly carbon structural steel, carbon tool steel, alloy tool steel, high speed steel and so on. The injection molding processing method is usually only applicable to the production of thermoplastic plastic products. The plastic products produced by the injection molding process are very wide, from daily necessities to various complicated machinery, electrical appliances, vehicle parts, etc., which are molded by injection molding. It is the most widely used processing method in the production of plastic products.

Plastic compression mould

It includes 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 is to heat the mold to the molding temperature (generally 103 ° C - 180 ° C) according to the characteristics of the plastic, and then put the metered plastic powder into the mold cavity and the feeding chamber, close the mold, and the plastic is in high heat and high pressure. The softening viscous flow underneath, after curing for a certain period of time, it becomes the shape of the desired product. Different from injection molding and compression molding, a separate feeding chamber is provided. Before molding, the mold is closed first, and the plastic is preheated in the feeding chamber to be in a viscous flow state, and is extruded into the mold cavity at a high speed under pressure to harden the molding. Compression molds are also used to mold certain special thermoplastics such as difficult-to-melt thermoplastic (such as Teflon) 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.

Plastic extrusion mould

It is a kind of mold used to form plastic products with continuous shape. It is also called extrusion molding machine head. It is widely used in the processing of pipes, bars, monofilaments, plates, films, wire and cable coatings, profiles and so on. The corresponding production equipment is a plastic extruder. The principle is that the solid plastic is melted and plasticized under the conditions of heating and extrusion screw rotation of the extruder, and the cross-section and the shape of the die are made through a specific shape of the die. Continuous plastic products. The manufacturing materials mainly include carbon structural steel, alloy tool steel, etc. Some extrusion dies are also embedded with wear-resistant materials such as diamond on the parts that need wear resistance. Extrusion processing is usually only applicable to the production of thermoplastic products, which are structurally distinct from injection molds and compression molds.

Plastic blow mould

It is a kind of mold used to mold hollow containers of plastic containers (such as beverage bottles, daily chemical products, etc.). The form of blow molding mainly consists of extrusion blow molding, injection molding and blow molding. Injection stretch blow molding hollow molding (commonly known as "injection blow"), multi-layer blow molding hollow molding, sheet blow molding hollow molding, and the like. The equipment corresponding to blow molding of hollow products is usually called plastic blow molding machine, and blow molding is only suitable for the production of thermoplastic products. The blow mold structure is relatively simple, and the materials used are mostly made of carbon steel.

Plastic blister mould

It is a kind of mold which is formed by using plastic plates and sheets as raw materials to form some simple plastic products. The principle is to use a vacuum forming method or a compressed air forming method to fix the plastic plates and sheets fixed on the die or the punch. When heated and softened, it is deformed and attached to the cavity of the mold to obtain the desired molded product, which is mainly used for the production of some daily necessities, foods, and toys. Because the pressure of the plastic mold is low during molding, the mold material is mostly made of cast aluminum or non-metal material, and the structure is relatively simple.

High expansion polystyrene molding die

It is a mold for forming foamed packaging materials of various desired shapes by using expandable polystyrene (beads composed of polystyrene and foaming agent). The principle is that the polystyrene can be steamed into the mold, including simple manual operation molds and hydraulic machine straight-through foam plastic molds, mainly used for the production of packaging products for industrial products. The materials for manufacturing such molds are cast aluminum, stainless steel, bronze, and the like.