(1) Working principle of injection molded parts
The working principle of injection molded parts is as follows. It uses the thrust of the screw (or plunger) to inject the plastic in the molten state (that is, the state of viscous fluid) into the closed mold cavity, and after solidification and molding, the product can be obtained.
(2) Injection molding process
Injection molding is a cyclic process, each cycle includes the following processes: quantitative feeding-melt plasticization-pressure injection-mold filling and cooling-mold opening and retrieval-closed mold closure.
(3) Operation items of injection molded parts
The operation items of injection molded parts include three aspects, namely control keyboard operation, electrical control system operation and hydraulic system operation. These three operating items will perform injection feeding actions, temperature monitoring of each part of the barrel, and adjustment options of injection pressure and injection speed.
(4) Molding process of general screw injection molded parts
First, the granular or powdered plastic is added to the barrel, and then the screw is rotated and the outer wall of the barrel is heated to make the plastic into a molten state.
Secondly, when the machine is closing the mold and the injection seat is moved forward, the nozzle should be close to the gate of the mold, and then pour the pressure oil into the injection cylinder and push the screw forward to melt the melt at a higher pressure and a higher speed. The body is injected into a closed mold.
Finally, after holding pressure and cooling, the injection molded part will solidify and form, and then the mold can be opened and the product can be taken out. Warm reminder, the purpose of pressure holding is to prevent the melt in the cavity from flowing back, so as to ensure that the product has a certain density and dimensional tolerance.
The basic requirements of injection molding are plasticization, injection and molding. Plasticization is the prerequisite for ensuring good quality of injection molded parts. In order to meet the molding requirements, injection must ensure sufficient pressure and speed. Due to the high injection pressure, it will also generate a lot of pressure in the mold cavity, so there must be sufficient clamping force during mold production. It can be seen that the injection device and the clamping device are the key components of the injection part.
(5) Judgment criteria for the quality of injection molded parts
First, the appearance quality of injection molded parts includes completeness, color, gloss, etc.
Secondly, the size and relative position of injection molded parts must be accurate.
Finally, the physical, chemical, and electrical properties of the injection molded parts must be in line with the application.
The above is the entire content of the injection molded parts. In fact, some injection molded parts also have defects. The defects of the product mainly lie in the design of the mold, the manufacturing accuracy and the degree of wear. If you want to know more about the mold, please click:Injection Mould Manufacturers