What is the working principle of the injection molding machine? What are the classifications of the injection molding machine? Some people have such a problem, we all know that the injection molding machine is the main molding equipment for making thermoplastics or thermosetting plastics into various shapes of plastic products using plastic molding molds.
So what is the working principle of the injection molding machine, and the next analysis:
First, the working principle of the injection molding machine
Injection molding is the use of the thermophysical properties of plastic, the material is added to the barrel from the hopper, the outer barrel is heated by the heating ring, the material is melted, and the barrel is equipped with a screw that drives rotation under the action of an external power motor, and the material is under the action of the screw;
Convey and compact along the screw groove forward, material is gradually plasticized, melted and homogenized under the dual action of external heating and screw shearing, when the screw rotates, the material is under the effect of friction and shear force of the screw groove, the molten material is pushed to the head of the screw, at the same time, the screw retreats under the reaction of the material, makes the head of the screw form a storage space, completes the plasticization process;
Then, under the effect of piston thrust of injection cylinder, screw rod with high speed, high pressure, the molten material in the storage chamber is injected into the cavity of mold through nozzle, and the molten material in the cavity is under the effect of clamping mechanism, after solidification and setting, mold opens mould under the effect of mould clamping mechanism, and through ejector device put and by ejector device, the finalized product is ejected and falls from mould.
Second, the classification of injection molding machines
According to the clamping parts and injection parts configuration type, there are three types: horizontal, vertical and angle
1. Horizontal injection molding machine:
Horizontal injection molding machines are the most commonly used type. It is characterized by the fact that the centerline of the injection assembly is concentric or consistent with the centerline of the clamping assembly and is parallel to the installation ground. Its advantages are low center of gravity, stable work, mold installation, operation and maintenance are more convenient, mold opening is large, occupies a small space height, but covers a large area, large, medium and small machines are widely used.
2. Vertical injection molding machine:
It is characterized by the alignment of the clamping device and the injection device in a line and perpendicular to the ground. It has the advantages of small footprint, convenient mold assembly and disassembly, easy insert installation, plasticizing of materials falling into the hopper more evenly, easy to realize automation and automatic line management of multiple machines. The disadvantage is that the ejection product is not easy to fall off automatically, and it is often necessary to take it out manually or by other methods, and it is not easy to achieve fully automatic operation and injection of large products.
3. Angular injection molding machine:
The axes of the injection unit and the clamping device are arranged perpendicular to each other. According to the relative position of the centerline of the injection assembly and the installation base surface, there are horizontal type, vertical and horizontal type: 1) horizontal type, injection assembly line is parallel to the base surface, and the center line of the mold clamping assembly is perpendicular to the base surface; 2) vertical and horizontal type, the center line of the injection assembly is perpendicular to the base surface, and the center line of the mold clamping assembly is parallel to the base surface. The advantage of the angle injection machine is that it has the advantages of both horizontal and vertical injection machines, and is especially suitable for molds with asymmetrical geometry of side gates.
Classification of injection molding machines
In fact, the working principle of the injection molding machine is similar to the syringe used for injection, which is to use the thrust of the screw (or plunger) to inject the plasticized molten state (i.e., viscous flow) plastic into the closed mold cavity, and obtain the process of obtaining the product after curing and shaping.
