According to the different molding methods, plastic pro […]
According to the different molding methods, plastic processing mold types corresponding to different process requirements can be divided, mainly including injection molding molds, extrusion molding molds, blister molding molds, and high foaming polystyrene molding molds.
1. Plastic injection (plastic) mold
It is mainly a molding die most commonly used in the production of thermoplastic products. The corresponding processing equipment for plastic injection molds is a plastic injection molding machine. The plastic is first heated and melted in the heating barrel of the injection machine, and then the screw of the injection machine. Or driven by the plunger, it enters the mold cavity through the injection system of the injection nozzle and the mold, and the plastic is cooled and hardened to form the product. Its structure is generally composed of molding parts, casting system, guide parts, push-out organization, temperature control system, exhaust system, support parts and other parts. The production materials generally use plastic mold steel modules. The commonly used materials are mainly carbon structural steel, carbon tool steel, alloy tool steel, and high-speed steel. The injection molding processing method is generally 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 kinds of messy machinery, electrical appliances, transportation parts, etc. are molded using injection molds. It is the most widely used processing method in the production of plastic products.
2. Plastic compression mould
Including two types of structural molds: compact molding and injection molding. They are a type of mold mainly used for molding thermosetting plastics, and the corresponding equipment is a pressure molding machine. The compact molding method is based on the characteristics of the plastic. The mold is heated to the molding temperature (generally between 103 ° and 108 °), and the measured compression molding powder is placed in the mold cavity and the feeding chamber. The mold is closed. The plastic is exposed to high heat and high pressure. It is softened and viscous. After a certain period of time, it is cured and shaped to become the desired product shape. Different from injection molding and compact molding, there is a separate feeding chamber. The mold is closed before molding. The plastic is preheated in the feeding chamber in a viscous flow state. It is adjusted into the mold cavity under the effect of pressure and hardened. Tightening molds are also used to mold certain special thermoplastics, such as hard-to-melt thermoplastics (such as polyvinylidene fluoride) blanks (cold compression molding), resin lenses with high optical properties, finely foamed nitrocellulose steering wheels, etc. . The compression mould is mainly composed of a cavity, a feeding cavity, a guide structure, a pushing part, a heating system and the like. Injection molds are widely used in the packaging of electrical components. The material used for the production of compression molds is basically the same as that of injection molds.
3.Plastic extrusion mold
A type of mold used to produce plastic products in continuous shapes, also known as extrusion heads, is widely used in the processing of pipes, rods, 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, plasticized under the conditions of heating and screw rotation and pressure of the extruder, and made into a die with a specific shape to have the same cross-section as the shape of the die. Successive plastic products. Its production materials mainly include carbon structural steel, alloy tools, etc. Some extrusion molds will be inlaid with diamond and other wear-resistant materials on parts that require wear resistance. The extrusion process is generally only applicable to the production of thermoplastic products, and its structure is significantly different from injection molds and compression molds.
4. Plastic blow mould
It is a mold used to mold plastic container hollow products (such as various packaging containers such as beverage bottles, daily chemical products, etc.). The form of blow molding is according to the principle of the process. There are extrusion blow molding and injection blow molding. 2, injection stretch blow molding hollow molding (commonly known as "injection stretch blow"), multilayer blow molding hollow molding, sheet blow molding hollow molding and so on. The corresponding equipment for blow molding of hollow products is generally called a plastic blow molding machine. 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 blister mould
It is a mold that uses plastic plates and sheets as the material to form some simpler plastic products. The principle is to use vacuum blooming or compressed air forming methods to make plastic plates and sheets fixed on concave or convex molds. Under the condition of heating and softening, it is deformed and pasted on the cavity of the mold to obtain the required 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 materials are mostly made of cast aluminum or non-metal materials, and the structure is relatively simple.
6.High foaming polystyrene molding mold
It is a mold that uses expandable polystyrene (bead material composed of polystyrene and foaming agent) to form foam packaging materials of various shapes. Its principle is that polystyrene can be steam-formed in the mold, including simple manual operation molds and hydraulic press straight-through foam plastic molds. It is mainly used to produce industrial packaging products. The materials for making such molds are cast aluminum, stainless steel, bronze and so on.