Analysis of the structure and working principle of injection molding machine


Injection molding machine is a special equipment that combines the hot working characteristics of plastic and the principle of melt die-casting molding of metal. * The initial plunger injection molding machine was only developed in the late 40s with a pre-plasticized screw injection molding machine. Since then, the focus of development has mainly revolved around pre-plasticized screw injection molding machines, and advanced forms such as twin screws and exhaust types have appeared after the line.

In 1980, France manufactured the world's largest screw injection molding machine, with an injection capacity of 170kg.From the 80s to recent years, the development of injection molding machines mainly focuses on several aspects: that is, the application of micro-automatic control system and various auxiliary equipment in automatic molding; precision machinery and high-performance hydraulic system cooperation; the development of various special injection molding machines and computer-aided design of complex shape plastic flow analysis to determine the best injection molding conditions; Application of various energy-saving technologies on injection molding machines.

First, the working principle of the injection molding machine

Injection molding machine is referred to as injection molding machine.

Injection molding is the use of the thermophysical properties of plastics, the material from the hopper into the barrel, the outside of the barrel by heating ring, so that the material melts, in the barrel is equipped with a screw driven by the external power motor to rotate, the material in the dual action of screw shear gradually plasticized, melted and homogenized, when the screw rotates, the material in the groove friction and shear force under the action, the molten material pushed to the screw head, at the same time, the screw retreats under the reaction of the material, so that the screw head forms a storage space, complete the plasticization process, Then the screw under the action of injection cylinder piston reasoning, with high speed and high pressure, the molten material in the storage room is injected into the mold cavity through the nozzle, and the melt in the cavity is pressurized, cooled, cured and shaped, and the mold opens the mold under the action of the mold clamping mechanism, and the finalized product is ejected from the mold and falls down through the ejection device.

Second, the composition of the injection molding machine will be composed of structural analysis

According to the requirements of injection molding process, the injection molding machine is a machine with strong mechatronics, which is mainly composed of injection parts, mold clamping parts, fuselage, hydraulic system, heating system, control system, feeding device, etc.

At present, common ear injection molding devices are single-cylinder and double-cylinder types.

There are two types of plasticized parts: plunger type and screw type. During the continuous pushing of the rotating screw, the plastic changes its physical state, and is injected into the mold cavity in a molten state. Therefore, the plasticized part is the core component to complete uniform plasticization and achieve quantitative injection.