Injection molding machine, also known as injection molding machine or injection machine

                  Injection molding machine, also known as injection molding machine or injection machine. It is the main molding equipment for making plastic products of various shapes from thermoplastic plastics or thermosetting plastics using plastic molding dies. Divided into vertical, horizontal, all-electric. The injection molding machine can heat the plastic, apply high pressure to the molten plastic, and eject it to fill the mold cavity.

                  The working principle of an injection molding machine is similar to that of a syringe used for injection. It uses the force of a screw (or plunger) to inject a plasticized molten state (ie, viscous flow state) into a closed mold cavity. After curing and setting, the process of the product is obtained.

                  Injection molding is a cyclic process, and each cycle mainly includes: quantitative feeding - melt plasticization - pressure injection - mold cooling - mold removal. Remove the plastic parts and then close the mold for the next cycle.

                  Injection molding machine operation items: Injection molding machine operation items include control of the keyboard operation, electrical control system operation and hydraulic system operation in three aspects. The injection process, the feeding action, the injection pressure, the injection speed, the ejection type selection, the temperature monitoring of each barrel section, the injection pressure, and the back pressure adjustment were performed.

                  The general molding process of the screw-type injection molding machine is as follows: First, the granular or powdery plastic is added into the barrel, and the plastic is melted by the rotation of the screw and the outer wall of the barrel, and the machine then performs mold clamping and injection seat advancement. The nozzle is tightly attached to the gate of the mold, and then the pressure oil is injected into the injection cylinder to advance the screw so that the molten material is injected into the closed mold with a relatively low temperature and a relatively high speed. The time and pressure are maintained (also called pressure keeping), cooling, solidifying and molding, then the product can be opened and removed. (The purpose of holding pressure is to prevent the backflow of the molten material in the cavity, to supplement the material in the cavity, and to ensure the products With a certain density and dimensional tolerances). The basic requirements for injection molding are plasticization, injection and molding. Plasticization is the prerequisite for achieving and ensuring the quality of molded products. In order to meet the requirements of molding, injection must ensure sufficient pressure and speed. At the same time, due to the high injection pressure, a very high pressure is generated in the mold cavity (the average pressure in the mold cavity is generally between 20 and 45 MPa), so a sufficient clamping force must be provided. It can be seen that the injection device and the mold clamping device are key components of the injection molding machine.

                  The evaluation of plastic products mainly includes three aspects. The first is the appearance quality, including the integrity, color, luster, etc.; the second is the accuracy between the size and relative position; the third is the physical and chemical properties corresponding to the purpose. Electrical properties. These quality requirements, in turn, vary depending on the use of the product. The defects of the products mainly lie in the design, manufacturing precision and wear degree of the molds. In fact, technicians in plastic processing plants often suffer from the difficulty of using technical means to make up for the problems caused by mold defects and have little effect.

                  The adjustment of the process in the production process is a necessary way to improve the quality and yield of the product. Because the injection cycle itself is very short, if the process conditions are not well mastered, waste products will continue to flow. When adjusting the craft, it is best to change only one condition at a time and observe several times at a time. If pressure, temperature, and time are unified and adjusted, it is easy to cause confusion and misunderstanding. If problems arise, you do not know what the reason is. The measures and means for adjusting the process are various. For example, there are more than a dozen possible solutions to solve the problem of unsatisfactory products. To solve the problem, one or two major solutions must be selected to solve the problem. In addition, we should also pay attention to the dialectical relationship in the solution. For example: The product has sunken, sometimes to raise the material temperature, sometimes to reduce the material temperature; sometimes to increase the amount of material, sometimes to reduce the amount of material. It is necessary to admit the feasibility of solving the problem with reverse measures.


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