Typical
injection molding machines include injection devices, clamping devices, hydraulic systems, and electrical control systems. The injection molding machine has a dense plastic product that can be molded in a complex shape, accurate in size or with metal inserts. It is widely used in electromechanical, automotive, transportation, building materials, packaging, agriculture, culture and health, national defense, and people's daily life. All areas of life. The injection molding process has good processing of various plastics, high productivity, and easy automation. In today's rapid development of the plastics industry, injection molding machines occupy an important position in terms of quantity and variety, and thus become one of the fastest growing and most productive models of plastic machinery.
Plastic injection molding technology was developed from the end of the 19th century to the beginning of the 20th century according to the principle of die casting. It is one of the most commonly used methods in plastic processing. This method applies to all thermoplastics and some thermoset plastics (about 1/3 of the total amount of plastics).
The working principle of the injection molding machine, the working principle of the injection molding machine is similar to that of the injection needle. It is the injection of the plasticized molten state (ie, the viscous flow state) into the closed by the thrust of the screw (or plunger). In a good cavity, the process of the product is obtained after curing and setting. Injection molding is a cyclic process, and each cycle mainly includes: quantitative feeding - melt plasticization - pressure injection - filling mold cooling - mold extraction. After removing the plastic part, the mold is closed again and the next cycle is performed.
The structure of the injection molding machine, the injection molding machine is divided into a plunger type injection molding machine and a screw type injection molding machine according to the plasticizing method; according to the transmission mode of the machine, it can be divided into hydraulic type, mechanical type and hydraulic-mechanical (linkage type); The method is divided into automatic, semi-automatic and manual injection molding machines.
(1) Horizontal injection molding machine: This is the most common type. The mold clamping portion and the injection portion are on the same horizontal center line, and the mold is opened in the horizontal direction. Its characteristics are: short body, easy to operate and maintain; low center of gravity, smooth installation; after the product is ejected, it can be automatically dropped by gravity, easy to achieve fully automatic operation. At present, injection molding machines on the market mostly adopt this type.
(2) Vertical injection molding machine: the clamping part and the injection part are on the same vertical center line, and the mold is opened in the vertical direction. Therefore, the floor space is small, the insert is easy to be placed, the mold is convenient to be loaded and unloaded, and the material falling from the hopper can be plasticized more uniformly. However, it is not easy to automatically fall after the product is ejected, and must be removed by hand, which is not easy to achieve automatic operation. The vertical injection molding machine should be used for small injection molding machines. Generally, it is used in injection molding machines below 60 grams, and large and medium-sized machines should not be used.
(3) Angle injection molding machine: the injection direction and the mold interface are on the same surface, and it is especially suitable for the planar product in which the machining center portion is not allowed to leave the gate mark. It has a smaller footprint than a horizontal injection molding machine, but the inserts placed in the mold are easily tilted down. This type of injection molding machine is suitable for small machines.
(4) Multi-mode rotary injection molding machine: It is a special injection molding machine with multi-station operation. Its characteristic is that the clamping device adopts a rotary structure, and the mold rotates around the rotating shaft. This type of injection molding machine fully utilizes the plasticizing ability of the injection device, can shorten the production cycle and increase the production capacity of the machine, and is therefore particularly suitable for large-volume molding which requires a long time for cooling or requires more auxiliary time for inserting the insert. The production of products, but because of the large and complex clamping system, the clamping force of the clamping device is often small, so the injection molding machine is more in the production of plastic soles and other products.
