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What are the classifications of plastic molds?

Update:10-12-2021
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 molds, extrusion molding molds, blister molding molds, high-foamed polystyrene molding molds, etc.

1. Plastic injection (plastic) mold

It is mainly a molding mold that is most commonly used in the production of thermoplastic parts. The corresponding processing equipment of the plastic injection mold is a plastic injection molding machine. Propelled by the screw or plunger, it enters the mold cavity through the nozzle of the injection machine and the pouring system of the mold, and the plastic is cooled and hardened to form, and the product is lost after being demolded. Its structure is usually composed of molding parts, pouring system, guide parts, push-out mechanism, temperature control system, exhaust system, support parts and other parts. 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. Injection molding processing methods are usually only suitable for the consumption of thermoplastic products. Plastic products consumed by injection molding technology are very common. From daily necessities to various complex machinery, electrical appliances, and transportation parts, they are all molded by injection molds. It is the most widely used processing method in the consumption of plastic products.

2. Plastic compression mould

It includes two structural mold types: compression molding and injection molding. They are a type of mold mainly used to mold thermosetting plastics, and their corresponding equipment is a pressure molding machine. According to the characteristics of the plastic, the compression molding method heats the mold to the molding temperature (usually 103°-108°), then puts the measured compression powder into the mold cavity and the feeding chamber, closes the mold, and the plastic is under high heat and high pressure. It is hardened and viscous, and after a certain period of time, it is solidified and shaped to become the desired product shape. The difference between injection molding and compression molding is that there is a separate feeding chamber. The mold is closed before molding. The plastic is preheated in the feeding chamber and is in a viscous flow state. It is adjusted and squeezed into the mold cavity under pressure to harden and form. Compression molds are also used to mold some special thermoplastics, such as hard-to-melt thermoplastics (such as polyvinyl fluoride) blanks (cold molding), resin lenses with high optical functions, and finely foamed nitrocellulose car steering wheels, etc. . The compression mold is mainly composed of a cavity, a feeding cavity, a guiding mechanism, an ejecting part, a heating system, etc. Injection molds are commonly used for packaging electrical components. The material used in the manufacture of compression molds is basically the opposite of that of injection molds.

3. Plastic extrusion mould

A type of mold used to mold plastic products with continuous appearance, also called extrusion molding head, is generally used for processing pipes, rods, monofilaments, plates, films, wire and cable coatings, profiled materials, etc. The corresponding consumer equipment is a plastic extruder. The principle is that the solid plastic is melted and plasticized under the conditions of heating and the screw of the extruder to rotate and pressurize, and the cross section is opposite to the shape of the die through a die with a specific shape. Continue plastic products. Its manufacturing materials mainly include carbon structural steel, alloy tools, etc. Some extrusion dies will also be inlaid with wear-resistant materials such as diamond on the parts that require wear-resistant. The extrusion process is usually only suitable for the consumption of thermoplastic products, and its structure is clearly different from injection molds and compression molds.

4. Plastic blow mould

It is a mold used to form hollow plastic container products (such as beverage bottles, daily chemical products and other packaging containers). The blow molding methods mainly include extrusion blow molding, hollow molding, and injection blow molding. , Injection stretch blow molding hollow molding (commonly known as "injection stretch blow"), multilayer blow molding hollow molding, sheet blow molding hollow molding, etc. The corresponding equipment for blow molding of hollow products is usually called a plastic blow molding machine, and blow molding is only suitable for the consumption of thermoplastic products. The structure of the blow mold is more complicated, and the materials used are mostly made of carbon.

5. Plastic blister mold

It is a kind of mold that uses plastic plates and sheets as raw materials to form some more complicated plastic products. Under the condition of heating and hardening, it deforms and sticks to the cavity of the mold to lose the required molded product. It is mainly used for the consumption of some daily necessities, food, and toy packaging products. Due to the low pressure during forming, the blister mold is made of cast aluminum or non-metallic materials, and the structure is more complicated.

6. High-expanded polystyrene molding die

It is a mold that uses expandable polystyrene (beads composed of polystyrene and foaming agent) raw materials to form various foamed plastic packaging materials with required shapes. The principle is that the expandable polystyrene can be steam-formed in the mold, including two types of simple manual molds and hydraulic straight-through foam plastic molds, which are mainly used for packaging products in consumer industrial products. The materials used to make this type of mold include cast aluminum, stainless steel, bronze and so on.