According to the different molding methods

Update:22-08-2018
Summary:

According to the different molding methods, the types o […]

According to the different molding methods, the types of plastic processing molds corresponding to different process requirements can be divided, mainly including injection molding dies, extrusion molding dies, blister molding dies, and high-expansion polystyrene molding dies.

1, 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 mold is a plastic injection molding machine. The plastic is first heated and melted in the heating barrel Injection mould of the injection machine, and then the screw of the injection machine. Or the plunger pushes, enters the mold cavity through the nozzle of the injection machine nozzle and the mold, the plastic is cooled and hardened, and the product is released. 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 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.

2, plastic compression mold

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 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.

3, plastic extrusion die

A type of mold used to form continuous shapes of plastic products, also known as extrusion heads, is widely used in the processing of pipes, rods, monofilaments, sheets, films, wire and cable coatings, profiles, and the like. 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 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 tools, etc. Some extrusion dies are also embedded with wear-resistant materials such as diamond on parts that require wear resistance. Extrusion process is usually only applicable to the production of thermoplastic products, which are structurally distinct from injection molds and compression molds.

4, plastic blow mold

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. 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 structure of the blow mold is relatively simple, and the materials used are mostly made of carbon.

5, plastic plastic mold

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 vacuuming 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.

6, high foam polystyrene molding mold

It is a mold for forming foamed packaging materials of various desired shapes by using expandable polystyrene (beads composed of polystyrene and a foaming agent). The principle is that the polystyrene can be steam-formed in 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 used to make such molds are cast aluminum, stainless steel, bronze, and the like.