The plastic injection molding machine works similarly to the syringe for injection. It uses the thrust of the screw (or plunger) to inject the plasticized molten state (ie, the viscous flow) into the closed cavity. The process of obtaining the product after curing and setting.
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 cooling large-volume plastics with long setting time or requiring more auxiliary time due to the inserting of 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.
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.
