What are the common types of plastic molds?

Time:

2023-04-07

According to the different molding methods, plastic molds can be divided into different types of plastic processing molds corresponding to different process requirements, which can be mainly divided into the following categories.

Plastic injection molds

　　The plastic is firstly heated and melted in the barrel at the bottom of the injection machine, and then pushed by the screw or plunger of the injection machine, it enters the cavity of the mold through the injection nozzle and the pouring system of the mold, the plastic is cooled and hardened, and the product is obtained by demoulding.

　　The structure usually consists of molding parts, pouring system, guiding parts, pushing mechanism, temperature regulating system, exhaust system, supporting parts and other parts.

　　The manufacturing material is usually plastic mold steel module, the common materials are mainly carbon structural steel, carbon tool steel, alloy tool steel, high-speed steel, etc.

　　Injection molding processing method is usually only applicable to the production of thermoplastic products, with injection molding process to produce a wide range of plastic products, from daily necessities to all kinds of complex machinery, electrical appliances, transportation parts, etc. are formed with injection molds, it is a more widely used processing method in the production of plastic products.

Plastic compression molding

　　Including compression molding and compression injection molding two types of structural mold. They are mainly used to mold thermosetting plastics, and their corresponding equipment is pressure molding machine. Compression molding method according to the characteristics of plastic, the mold is heated to the molding temperature (generally in 103 ° - 108 °), and then the measured compression molding powder into the mold cavity and filling chamber, close the mold, plastic in high heat, high pressure is softened viscous flow, after a certain period of time curing shape, become the desired product shape.

　　Press injection molding is different from compression molding in that there is a separate filling chamber, and the mold is closed before molding, and the plastic is preheated in the filling chamber and becomes viscous flow, and then it is adjusted and squeezed into the mold cavity under pressure to harden and mold. Compression molds are also used to mold certain special thermoplastics such as difficult to melt thermoplastics (such as polyvinylidene fluoride) blanks (cold compression molding), resin lenses with high optical properties, nitrocellulose car steering wheels with slight foaming, etc.

　　The compression molding mold is mainly composed of cavity, filling cavity, guiding mechanism, push out parts, heating system, etc. Compression injection molds are widely used in encapsulating electrical components. The materials used in the manufacture of compression molding dies are basically the same as injection molds.

Plastic extrusion mold

　　A type of mold used to mold and produce continuous shaped plastic products, also called extrusion molding head, widely used in the processing of pipes, rods, monofilaments, plates, films, wire and cable cladding, profiles, etc. Its corresponding production equipment is a plastic extruder, whose principle is to melt and plasticize solid plastic under the conditions of heating and extruder's screw rotation and pressure, and make continuous plastic products with the same cross-section as the shape of the mouth mold through a specific shape of the mouth mold.

　　Its manufacturing materials are mainly carbon structural steel, alloy tools, etc. Some extrusion dies are also inlaid with wear-resistant materials such as diamond in the parts that need to be wear-resistant. The extrusion process is usually only applicable to the production of thermoplastic products, and its structure is obviously different from that of injection molds and compression molds.

Plastic Blow Molding Molds

　　It is a kind of mold used for molding plastic container hollow products (such as beverage bottles, daily chemical products and other packaging containers), and the forms of blow molding are mainly extrusion blow molding, injection blow molding, injection extension blow molding (commonly known as "injection pull blow"), multi-layer blow molding, sheet blow molding, etc. Forming, etc.

　　Blow molding of hollow products corresponding to the equipment is usually called plastic blow molding machine, blow molding is only applicable to the production of thermoplastic varieties of products. Blow molding mold structure is relatively simple, and the materials used are mostly made of carbon more then.

Plastic suction molding mold

　　It is a kind of mold that takes plastic plate and sheet as raw material to form some simple plastic products. Its principle is to use the method of evacuation and opening or compressed air forming method to make the plastic plate and sheet fixed on the concave mold or convex mold, deforming and sticking on the cavity of the mold under the condition of heating and softening to get the required formed products, mainly used in the production of some daily necessities, food and toy packaging products. Because of the low pressure of blister mold, the mold material is mostly made of cast aluminum or non-metal material, and the structure is simple.

High foam polystyrene molding mold

　　It is a kind of mold that applies the raw material of EPS (bead material composed of polystyrene and foaming agent) to form various foam packaging materials of desired shapes. The principle is that EPS can be molded into steam in the mold, including simple hand-operated molds and hydraulic machine straight-through foam molds of two types, mainly used for the production of industrial packaging products.

　　The materials used in the manufacture of such molds are cast aluminum, stainless steel, bronze, etc.