Different types of molds used in common plastic product molding


Mould is an important technological equipment in modern […]

Mould is an important technological equipment in modern industry and an indispensable part in the production of many industrial products. After my country's entry into the WTO, its ability to attract foreign capital has been enhanced year by year, and its status as a world product manufacturing factory has become more and more prominent, and more and more industrial molds are imported.

The types of molds are usually classified according to the different processing objects and processes. From the perspective of the industry, there are mainly plastic molds, rubber molds, metal cold stamping dies, metal cold extrusion dies and hot extrusion dies, and metal drawing dies. , powder metallurgy mold, metal die-casting mold, metal precision casting mold, glass mold, glass fiber reinforced plastic mold and so on.

The following is only how to classify and introduce the different types of molds used in the molding and processing of common imported plastic products.

The common molding methods of plastics are generally divided into two categories: melt molding and solid-phase molding: melt molding is a method of heating plastic to above the melting point and making it in a molten state for molding, which belongs to the molding process of this molding method. Mainly include injection molding, compression molding (shrinkage) 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, compressed air molding and Blow molding, etc. In addition, there are liquid molding methods, such as casting molding, slush molding and dip molding.

According to the different molding methods above, 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, blister molding molds, high-foaming polystyrene Vinyl forming molds, etc.

Plastic injection (plastic) mold

It is mainly a molding mold that is widely 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 at the bottom of the injection machine, and then in the Driven by the screw or plunger, it enters the mold cavity through the injection machine nozzle and the pouring system of the mold, and the plastic is cooled and hardened to form, and demolded to obtain the product. Its structure usually consists of forming parts, pouring system, guiding parts, pushing mechanism, temperature regulation system, exhaust system, supporting parts and other parts. The manufacturing materials usually use plastic mold steel modules, and the commonly used materials are mainly carbon structural steel, carbon tool steel, alloy tool steel, high-speed steel, etc. The injection molding processing method is usually only suitable for the production of thermoplastic products. The plastic products produced by the injection molding process are very wide, ranging from daily necessities to various complex machinery, electrical appliances, and transportation parts. It is a widely used processing method in the production of plastic products.

Plastic Compression Mould

Including compression molding and injection molding two structural mold types. They are a type of mold mainly used for molding thermosetting plastics, and their corresponding equipment is a pressure molding machine. The compression molding method is to heat the mold to the molding temperature (usually 103 ° C - 180 ° C) according to the characteristics of the plastic, and then put the measured compression molding powder into the mold cavity and the feeding chamber, close the mold, and the plastic is under the action of high heat and high pressure. The bottom is softened and viscous flow, and after a certain period of time, it will be solidified and shaped into the desired shape of the product. The difference between injection molding and compression molding is that there is a separate feeding chamber. Before molding, the mold is closed first. The plastic is preheated in the feeding chamber and is in a viscous flow state. Under the action of pressure, it is squeezed into the mold cavity at a high speed and hardened. Compression molds are also used to form some special thermoplastics such as hard-to-melt thermoplastics (such as polytetrafluoroethylene) blanks (cold pressing), resin lenses with high optical properties, slightly foamed nitrocellulose car steering wheels, etc. . The compression mold is mainly composed of cavity, feeding cavity, guiding mechanism, ejecting parts, heating system, etc. Injection molds are widely used in packaging electrical components. The materials used in the manufacture of compression molds are basically the same as injection molds.

Plastic Extrusion Die

It is a type of mold used to shape and produce continuous-shaped plastic products, also known as extrusion molding head. It is widely used in the processing of pipes, bars, monofilaments, plates, films, wire and cable coatings, and profiles. 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 the screw rotation and pressure of the extruder, and is made into the same cross-section as the shape of the die through a specific shape of the die. Continuous plastic products. Its manufacturing materials are mainly carbon structural steel, alloy tool steel, etc., and some extrusion dies are also inlaid with wear-resistant materials such as diamond on the parts that need wear-resistant. The extrusion process is usually only suitable for the production of thermoplastic products, which are significantly different from injection molds and compression molds in structure.

Plastic blow mold

It is a mold used to form plastic container hollow products (such as beverage bottles, daily chemical products and other packaging containers). The form of blow molding mainly includes extrusion blow molding and injection blow molding according to the process principle. , Injection stretch blow molding (commonly known as "injection stretch blow"), multilayer blow molding, sheet blow molding, etc. 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 steel.

Plastic plastic mold

It is a kind of mold that uses plastic plates and sheets as raw materials to form some relatively simple plastic products. In the case of heating and softening, it is deformed and attached to the cavity of the mold to obtain the desired molded product, which is mainly used in the production of some daily necessities, food, and toy packaging products. Due to the low pressure during molding, the mold material is mostly made of cast aluminum or non-metallic materials, and the structure is relatively simple.

High-expanded polystyrene molding die

It is a mold for forming foam packaging materials of various desired shapes by using expandable polystyrene (bead-like particles composed of polystyrene and foaming agent). The principle is that expandable polystyrene is steamed in the mold, including two types of simple manual operation molds and hydraulic straight-through foam plastic molds, which are mainly used to produce packaging products for industrial products. The materials for making such molds are cast aluminum, stainless steel, bronze, etc..